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We use electromagnetic communication everywhere these days. Cell phones, wifi, old-school radio transmissions, television, deep space communication, etc.
I'm curious about some of the possible reasons we have never seen biological systems having evolved to use electromagnetic, i.e. radio, for communication. The one obvious exception to this are organisms that generate their own light, i.e. bioluminescence. Cuttlefish are masters of this, and many other species as well.
It seems like bio-radio could have offered all kinds of evolutionary advantages for animals capable of using it.
Are their basic physical limits in chemistry, or excess energy requirements or something that would basically have made this impossible? Or was this perhaps just something that life never evolved to use, but would otherwise be possible in evolution?
There is a very different mechanism for generation (and detection) of ultraviolet, visible and infrared light vs radio waves.
For the first, it is possible to generate it using chemical reactions (that is, chemiluminescence, bioluminescence) with a typical energy of order of 2 eV (electronovolts). Also, it is easy to detect with similar means - coupling to a bond (e.g. using opsins).
For much longer electromagnetic waves, and much lower energies per photon, such mechanism does not work. There are two reasons:
- typical energy levels for molecules (but it can be worked around),
- thermal noise has energies (0.025 eV) which are higher than radio wave photon energies (<0.001 eV) (it rules out both controlled creation and detection using molecules).
In other words - radiation which is less energetic than thermal radiation (far infrared) is not suitable for communication using molecular mechanisms, as thermal noise jams transmission (making the sender firing at random and making the receiver being blind by noise way stronger than the signal).
However, one can both transmit, and detect it, using wires. In principle it is possible; however, without good conductors (like metals, not - salt solutions) it is not an easy task (not impossible though).
Because the intermediate stages are not evolutionarily favoured. That's why.
Sound and light perception are useful without any generative capability. An organism with a tiny amount of perception for either of these things has an advantage over those without; and an organism with a tiny amount more has an advantage over those with a tiny bit less. This advantage forms the basis for selection and thus improved sensory capabilities (balanced, of course, by the cost of those capabilities).
Being able to perceive radio on the other hand provides no useful information about the world at low level perception so even if an organism was to randomly mutate so as to detect radiowaves* there would be no selection for this ability, and thus no mechanism to drive the evolution of advanced radio reception. Without the ability to perceive radiowaves there is no possibility of evolving the ability to generate radio signals in a controlled manner.
*-In fact, since radiowaves generally interact very little with organic materials unlike heat, light and sound even this first step of random mutation is much less likely than for sense that have evolved.
Actually, electromagnetic communication is used by certain fish, the mormyrids and the gymnotids. Pulse modulated in the former and amplitude modulated in the latter.
However, the frequencies used are not much greater than 1Khz, which is not what we ordinarily consider to be in the radio frequency spectrum.
There is, too, another biological species in which the use of the full RF spectrum has evolved. Its activities even extend to the use of the UV and X-ray frequencies.
That species is our own. I am not being flippant here. We must not fall into the trap of considering ourselves as apart from nature. Contrary to our usual intuitions, technologies have evolved autonomously within the collective imagination of our species.
The broader evolutionary model which supports this contention is outlined, very informally, in "The Goldilocks Effect: What Has Serendipity Ever Done For Us?" , a free download in e-book formats from the "Unusual Perspectives" website.
I just found a research about possibility of organism with loop DNA (Mostly bacteria) could use there DNA as antenna to transmit and receive radio wave around 1kHz
But as other said. Communication mostly evolve from sensory organ. So the radio wave has too much noise and could not give useful information about situation. They don't selectively evolve to the point that they could be used to communicate
But the bacteria has inherently possibility from start. So they may actually do some communication
A quick comparison between light and sound vs. Radio
- Light: Wavelength 380 nm -740 nm
- Sound: 17 mm - 17 m
- Radio: 1mm - 10e5 km
From the Planck relation, the energy of a wave is inversely proportional to the wavelength. As a result light is stronger than sound which is stronger than FM radio which is stronger than AM radio. Very likely, the energy density provided by radio is far too weak to have meaningful signal processing.
However, there are some uses in the radio frequency. Bat echolocation occurs at a frequency of 14,000 to 100,000 Hz which is well within the radio frequency.
Devolution, de-evolution, or backward evolution is the notion that species can revert to supposedly more primitive forms over time. The concept relates to the idea that evolution has a purpose (teleology) and is progressive (orthogenesis), for example that feet might be better than hooves or lungs than gills. However, evolutionary biology makes no such assumptions, and natural selection shapes adaptations with no foreknowledge of any kind. It is possible for small changes (such as in the frequency of a single gene) to be reversed by chance or selection, but this is no different from the normal course of evolution and as such de-evolution is not compatible with a proper understanding of evolution due to natural selection.
In the 19th century, when belief in orthogenesis was widespread, zoologists (such as Ray Lankester and Anton Dohrn) and the palaeontologists Alpheus Hyatt and Carl H. Eigenmann advocated the idea of devolution. The concept appears in Kurt Vonnegut's 1985 novel Galápagos, which portrays a society that has evolved backwards to have small brains.
Dollo's law of irreversibility, first stated in 1893 by the palaeontologist Louis Dollo, denies the possibility of devolution. The evolutionary biologist Richard Dawkins explains Dollo's law as being simply a statement about the improbability of evolution's following precisely the same path twice.
How Did Human Language Evolve? Scientists Still Don't Know
Humans have language and other animals don’t. That’s obvious, but how it happened is not. Since Darwin’s time , scientists have puzzled over the evolution of language. They can observe the present-day product: People today have the capacity for language, whether it be spoken, signed or written. And they can infer the starting state: The communication systems of other apes suggest abilities present in our shared ancestor.
But the million-dollar question is what happened in between . How did we transition from ape-like communication to full-fledged human language?
Most scientists think this happened in stages , as our ancestors evolved the adaptations needed for language. In earlier stages, human ancestors would have used a kind of protolanguage — more complex than ape communication, but lacking elements of modern language.
But what exactly was this protolanguage like? That’s where we hit considerable debate. Some researchers argue that our ancestors sang before they spoke . Others claim protolanguage was dominated by pantomimed gestures — a society built on charades.
Here, I’ll do my best to summarize prevailing models for language origins, drawing largely from a 2017 academic review by evolutionary biologist W. Tecumseh Fitch.
What Makes Language, Language
Before trying to explain how language evolved, we need to clarify exactly what evolved. We must define what language is and how it differs from the communication abilities of our closet evolutionary relatives, the great apes.
In human language , arbitrary sounds and signs represent specific words, which can be learned, invented and infinitely combined within grammatical structures. We can talk about anything we can think — plans, pancakes, politics — including what is not the case: “I have no plans to make pancakes or enter politics.” And many statements have specific meanings that are context dependent. For instance, “How are you?” can be a greeting, not a genuine inquiry. Language allows us to bond with others, or to deceive them. And although our native tongue is not innate, toddlers pick it up without conscious effort.
These qualities make language an extraordinary communication system found exclusively in humans. But the system can be dissected into components, or traits necessary for language. And these emerged at different times in our evolutionary past. Traits shared with other apes likely existed millions of years ago in our common ancestor. The traits we don’t see in other apes probably only emerged in hominins, the evolutionary branch that includes humans and our extinct relatives.
There are at least three elements of language only present in hominins:
First, is a fine-control over our vocal tracts. Other apes are likely born with a more limited repertoire of vocalizations. The difference comes down to how our brains are wired: Humans have direct connections between the neurons controlling our voice box and the motor cortex, the region of our brain responsible for voluntary movements. Brain scans show these connections are lacking in other primates.
Next is our tendency to communicate for the sake of communicating . To encapsulate this, biologist Fitch used the German word Mitteilungsbedürfnis , “the drive to share thoughts.” Whereas chimps use a finite set of calls and gestures to convey the essentials — food, sex and danger — humans talk to bond and exchange ideas, and strive to ensure we’re understood. Most researchers attribute this difference to an idea called “theory of mind,” the understanding that others have thoughts. Chimps demonstrate more limited theory of mind, whereas humans know that other humans think things — and we’re constantly using language to uncover and influence those thoughts.
The last difference is hierarchical syntax. Phrases and sentences have nested structure and these provide meaning beyond the simple sequence of words. For instance, take the sentence: “Chad, who was out to lunch with Tony, was late to the meeting.” Hierarchical syntax processing allows us to correctly interpret that Chad was late to the meeting, even though “Tony” is closer to the verb “was late.” Over 60 years ago and still today , linguist Noam Chomsky proposed hierarchical syntax as the key to language.
So hypotheses for language origins must explain (at least) these three traits: precise vocal learning and control, overtly social communication and hierarchical syntax.
Leading Views on Language Evolution
Now for the fun part: How did these components emerge, and eventually converge, to constitute language?
There are several prevailing views, which differ in terms of the evolutionary pressures favoring language adaptations, the order these adaptations arose and the nature of protolanguage along the way.
Some believe precise vocal control and learning was the first language trait to emerge in hominins — and not for speaking, but for singing. This idea of musical protolanguage comes from Darwin himself and has been modified over the years by different researchers . During this hypothetical singing stage of human evolution, our ancestors’ survival and/or reproductive success would have depended on serenading, in the context of maintaining social bonds , attracting mates or soothing infants . (Given my repulsion for acapella, I’d be evolutionarily unfit for this phase).
An alternate view envisions protolanguage characterized by gesture and pantomime. In this case, syntax and social communication would have preceded vocal prowess. The strength of the gestural hypothesis is that our closest relatives, chimpanzees, exhibit more controlled and variable gestures ( over 70 and counting ) than calls ( 4 types and more hard-to-distinguish subtypes). The weakness of this view is, it’s unclear why or how language became so speech-dominate.
Others, convinced that hierarchical syntax emerged last, propose a protolanguage with symbolic words, but no complex, nested sentences. According to this view, our pre-linguistic ancestors talked more like babies — “Water! Thirsty!” — or pop-culture’s image of cavemen — “Me hunt mammoth. Me want sex.”
These models aren’t mutually exclusive. Some researchers integrate them into successive stages, associated with different hominin species. Perhaps between 2 and 4 million years ago, Australopiths like Lucy were gifted singers. By 1.9 million years ago Homo erectus combined gestures and expressive vocalizations into group rituals. And hierarchical syntax only emerged some 200,000- 300,000 years ago with the appearance of our species, Homo sapiens.
Why Does Evolution Matter?
Grains, such as wheat and corn provide 75% of the food the world eats. Today, a corn plant produces twice the grain it did 30 years ago, and probably 10 times what it could a century ago. Why? Because we know -- we have found out -- that living things are changeable. Over many generations we can change them into things that serve us better. Nowadays we do it very systematically and on purpose. We've done it more haphazardly for thousands of years. Somewhere in our dim past we discovered that if we mate our best plants and animals, or save the best seeds, and destroy or eat the less perfect ones, each generation will get slightly better -- more fit, by our standards. But corn, for instance, is still being improved, and still has enemies. One way we could improve it is to find its wild ancestor, the native grass that our ancestors started cultivating. The problem is that we have changed corn so much that it now looks very different from any wild grasses. But understanding that corn has evolved has allowed agricultural researchers to find its wild cousin. Now, using the science of genetics, we can "borrow" genes from that relative to improve corn. We are making it more resistant to disease and insects, and more tolerant of salt and drought.
That's one thing we can do with a knowledge of evolution and genetics: feed a hungry world. Research into improving animals - livestock - is just as dependent on modern evolutionary biology. How could we even conceive of using ancestral genes to improve breeds if we thought all plants and animals were just created, in their present forms?
If you want to see evolution in action, all you have to do is look for things with very short times between generations: insects, for instance. A major problem with bugs (from our point of view) is that their generations are so short that they can evolve fast. So what? So every farmer must be painfully aware that he has to be very careful about how he uses pesticides. If he uses too much, too often, he may force bugs to evolve rapidly and become resistant, so that the poison no longer kills them. This isn't "just a theory" -- it happens.
There are many pesticides that are now useless, because the bugs they were used on have evolved into something that is no longer bothered by those poisons. They may not be new species yet, but they are no longer the same insects, either. The U.S. Department of Agriculture and the multi-national, multi-billion-dollar agribusinesses take evolution very seriously .
Consider those other "bugs": germs. Modern hospitals have learned the hard way just how fast bacteria can evolve. They have accidentally "created," by using too many antibiotics, new breeds of super-germs that have evolved resistance to antibiotics. It's now a race: can we find new antibiotics fast enough to keep up with the mutation-and-natural-selection rates of killers like resistant staphylococcus? And if we do find something that kills it, do we run the risk of forcing it to just evolve again into an even more unstoppable form?
Our first step in understanding AIDS was to figure out what it had evolved from -- it didn't just appear magically. We have also discovered that it will be very difficult to make an AIDS vaccine, because the HIV virus has developed the trick of evolving so fast, that something that prevents it this year, probably won't next year. Another of its tricks is to mutate (evolve) into many different strains within each victim's body, so that the immune system can never find and eliminate all the viruses. If researchers didn't know that life has always changed, and continues to change -- if they didn't believe in evolution -- how could they deal with the turbo-charged evolutionary rates of these tiniest and deadliest life forms?
Finally, a (true) horror story. A few years ago there was a little girl, known to the concerned public as "Baby Fae," who needed a heart transplant. Human donors are hard to find, especially for infants, so a daring surgeon convinced the parents to let him implant a baboon's heart. A hopeful world held its breath, while skeptical biologists scratched their heads (a baboon's heart?), but everyone hoped for the best. Sadly, Baby Fae died after a few weeks. Among the contributing factors may have been that her immune system had recognized the heart as something foreign, and attacked it. After the sensational news stories had died down, it was reported that a biologist asked the surgeon why he had chosen a baboon donor, which is a much more distant relative of ours (in evolutionary terms) than a chimpanzee, which is our closest relative. Wouldn't there have been less danger of rejection with a heart from a closer relative? The surgeon's answer: he hadn't even taken that into consideration, because he didn't believe in evolution! To him, no creatures were related to each other, since they had all been created at once, in their present forms. Maybe a chimpanzee's heart would not have saved Baby Fae either, but the chances might have been better. One would think that a doctor or scientist would want to use the best available knowledge, such as what we understand about evolutionary biology and the relationships of organisms.
1. What is the main point of the article?
a. evolution is an important and useful theory
b. evolution is a theory that has not been proven
c. we should improve crops to feed more people
d. we should not tamper with nature
2. Why must farmers be careful about the pesticides they use?
a. they could poison the land and harm other organisms
b. they crops may die
c. insects may become resistant
d. so that they can produce better crops
3. Why is it difficult to create a vaccine for AIDS?
a. the virus is too well hidden in the body
b. the virus is constantly changing
c. vaccines only work on bacterial infections
d. not enough research money
4. Years ago, doctors would prescribe antibiotics for many symptoms of a common cold. Today, it is much more difficult to get a prescription. Why has the medical industry changed its procedures?
a. too many antibiotics can create resistant bacteria
b. pharmaceutical companies objected to the amount of prescriptions
c. antibiotics can make people sick
d. doctors are against prescribing medicines
5. To see evolution in action, you should look at organisms with:
a. short lifespans
b. complex body systems
c. large populations
d. short amount of time between generations
Short Answer (use complete sentences!)
1. Describe two ways in which the evolution of organisms can have a harmful effect on humans.
2. Name two ways that the Theory of evolution is currently being used to improve the quality of human life?
3. Why did the doctor NOT choose a chimpanzee heart to donate to Baby Fae? Do you think the baby’s chances would have been better if he had?
4. What do you think is the main message the author wanted to get across with this article?
102 Determining Evolutionary Relationships
By the end of this section, you will be able to do the following:
- Compare homologous and analogous traits
- Discuss the purpose of cladistics
- Describe maximum parsimony
Scientists must collect accurate information that allows them to make evolutionary connections among organisms. Similar to detective work, scientists must use evidence to uncover the facts. In the case of phylogeny, evolutionary investigations focus on two types of evidence: morphologic (form and function) and genetic.
Two Options for Similarities
In general, organisms that share similar physical features and genomes are more closely related than those that do not. We refer to such features that overlap both morphologically (in form) and genetically as homologous structures. They stem from developmental similarities that are based on evolution. For example, the bones in bat and bird wings have homologous structures ((Figure)).
Notice it is not simply a single bone, but rather a grouping of several bones arranged in a similar way. The more complex the feature, the more likely any kind of overlap is due to a common evolutionary past. Imagine two people from different countries both inventing a car with all the same parts and in exactly the same arrangement without any previous or shared knowledge. That outcome would be highly improbable. However, if two people both invented a hammer, we can reasonably conclude that both could have the original idea without the help of the other. The same relationship between complexity and shared evolutionary history is true for homologous structures in organisms.
Some organisms may be very closely related, even though a minor genetic change caused a major morphological difference to make them look quite different. Similarly, unrelated organisms may be distantly related, but appear very much alike. This usually happens because both organisms were in common adaptations that evolved within similar environmental conditions. When similar characteristics occur because of environmental constraints and not due to a close evolutionary relationship, it is an analogy or homoplasy. For example, insects use wings to fly like bats and birds, but the wing structure and embryonic origin is completely different. These are analogous structures ((Figure)).
Similar traits can be either homologous or analogous. Homologous structures share a similar embryonic origin. Analogous organs have a similar function. For example, the bones in a whale’s front flipper are homologous to the bones in the human arm. These structures are not analogous. A butterfly or bird’s wings are analogous but not homologous. Some structures are both analogous and homologous: bird and bat wings are both homologous and analogous. Scientists must determine which type of similarity a feature exhibits to decipher the organisms’ phylogeny.
This website has several examples to show how appearances can be misleading in understanding organisms’ phylogenetic relationships.
The advancement of DNA technology has given rise to molecular systematics , which is use of molecular data in taxonomy and biological geography (biogeography). New computer programs not only confirm many earlier classified organisms, but also uncover previously made errors. As with physical characteristics, even the DNA sequence can be tricky to read in some cases. For some situations, two very closely related organisms can appear unrelated if a mutation occurred that caused a shift in the genetic code. Inserting or deleting a mutation would move each nucleotide base over one place, causing two similar codes to appear unrelated.
Sometimes two segments of DNA code in distantly related organisms randomly share a high percentage of bases in the same locations, causing these organisms to appear closely related when they are not. For both of these situations, computer technologies help identify the actual relationships, and, ultimately, the coupled use of both morphologic and molecular information is more effective in determining phylogeny.
Why Does Phylogeny Matter? Evolutionary biologists could list many reasons why understanding phylogeny is important to everyday life in human society. For botanists, phylogeny acts as a guide to discovering new plants that can be used to benefit people. Think of all the ways humans use plants—food, medicine, and clothing are a few examples. If a plant contains a compound that is effective in treating cancer, scientists might want to examine all of the compounds for other useful drugs.
A research team in China identified a DNA segment that they thought to be common to some medicinal plants in the family Fabaceae (the legume family). They worked to identify which species had this segment ((Figure)). After testing plant species in this family, the team found a DNA marker (a known location on a chromosome that enabled them to identify the species) present. Then, using the DNA to uncover phylogenetic relationships, the team could identify whether a newly discovered plant was in this family and assess its potential medicinal properties.
Building Phylogenetic Trees
How do scientists construct phylogenetic trees? After they sort the homologous and analogous traits, scientists often organize the homologous traits using cladistics . This system sorts organisms into clades: groups of organisms that descended from a single ancestor. For example, in (Figure), all the organisms in the orange region evolved from a single ancestor that had amniotic eggs. Consequently, these organisms also have amniotic eggs and make a single clade, or a monophyletic group . Clades must include all descendants from a branch point.
Which animals in this figure belong to a clade that includes animals with hair? Which evolved first, hair or the amniotic egg?
Clades can vary in size depending on which branch point one references. The important factor is that all organisms in the clade or monophyletic group stem from a single point on the tree. You can remember this because monophyletic breaks down into “mono,” meaning one, and “phyletic,” meaning evolutionary relationship. (Figure) shows various clade examples. Notice how each clade comes from a single point whereas, the non-clade groups show branches that do not share a single point.
What is the largest clade in this diagram?
Organisms evolve from common ancestors and then diversify. Scientists use the phrase “descent with modification” because even though related organisms have many of the same characteristics and genetic codes, changes occur. This pattern repeats as one goes through the phylogenetic tree of life:
- A change in an organism’s genetic makeup leads to a new trait which becomes prevalent in the group.
- Many organisms descend from this point and have this trait.
- New variations continue to arise: some are adaptive and persist, leading to new traits.
- With new traits, a new branch point is determined (go back to step 1 and repeat).
If a characteristic is found in the ancestor of a group, it is considered a shared ancestral character because all of the organisms in the taxon or clade have that trait. The vertebrate in (Figure) is a shared ancestral character. Now consider the amniotic egg characteristic in the same figure. Only some of the organisms in (Figure) have this trait, and to those that do, it is called a shared derived character because this trait derived at some point but does not include all of the ancestors in the tree.
The tricky aspect to shared ancestral and shared derived characters is that these terms are relative. We can consider the same trait one or the other depending on the particular diagram that we use. Returning to (Figure), note that the amniotic egg is a shared ancestral character for the Amniota clade, while having hair is a shared derived character for some organisms in this group. These terms help scientists distinguish between clades in building phylogenetic trees.
Choosing the Right Relationships
Imagine being the person responsible for organizing all department store items properly—an overwhelming task. Organizing the evolutionary relationships of all life on Earth proves much more difficult: scientists must span enormous blocks of time and work with information from long-extinct organisms. Trying to decipher the proper connections, especially given the presence of homologies and analogies, makes the task of building an accurate tree of life extraordinarily difficult. Add to that advancing DNA technology, which now provides large quantities of genetic sequences for researchers to use and analzye. Taxonomy is a subjective discipline: many organisms have more than one connection to each other, so each taxonomist will decide the order of connections.
To aid in the tremendous task of describing phylogenies accurately, scientists often use the concept of maximum parsimony , which means that events occurred in the simplest, most obvious way. For example, if a group of people entered a forest preserve to hike, based on the principle of maximum parsimony, one could predict that most would hike on established trails rather than forge new ones.
For scientists deciphering evolutionary pathways, the same idea is used: the pathway of evolution probably includes the fewest major events that coincide with the evidence at hand. Starting with all of the homologous traits in a group of organisms, scientists look for the most obvious and simple order of evolutionary events that led to the occurrence of those traits.
Head to this website to learn how researchers use maximum parsimony to create phylogenetic trees.
These tools and concepts are only a few strategies scientists use to tackle the task of revealing the evolutionary history of life on Earth. Recently, newer technologies have uncovered surprising discoveries with unexpected relationships, such as the fact that people seem to be more closely related to fungi than fungi are to plants. Sound unbelievable? As the information about DNA sequences grows, scientists will become closer to mapping the evolutionary history of all life on Earth.
To build phylogenetic trees, scientists must collect accurate information that allows them to make evolutionary connections between organisms. Using morphologic and molecular data, scientists work to identify homologous characteristics and genes. Similarities between organisms can stem either from shared evolutionary history (homologies) or from separate evolutionary paths (analogies). Scientists can use newer technologies to help distinguish homologies from analogies. After identifying homologous information, scientists use cladistics to organize these events as a means to determine an evolutionary timeline. They then apply the concept of maximum parsimony, which states that the order of events probably occurred in the most obvious and simple way with the least amount of steps. For evolutionary events, this would be the path with the least number of major divergences that correlate with the evidence.
Visual Connection Questions
(Figure) Which animals in this figure belong to a clade that includes animals with hair? Which evolved first, hair or the amniotic egg?
(Figure) Rabbits and humans belong in the clade that includes animals with hair. The amniotic egg evolved before hair because the Amniota clade is larger than the clade that encompasses animals with hair.
(Figure) What is the largest clade in this diagram?
(Figure) The largest clade encompasses the entire tree.
Which statement about analogies is correct?
- They occur only as errors.
- They are synonymous with homologous traits.
- They are derived by similar environmental constraints.
- They are a form of mutation.
What do scientists use to apply cladistics?
What is true about organisms that are a part of the same clade?
- They all share the same basic characteristics.
- They evolved from a shared ancestor.
- They usually fall into the same classification taxa.
- They have identical phylogenies.
Why do scientists apply the concept of maximum parsimony?
- to decipher accurate phylogenies
- to eliminate analogous traits
- to identify mutations in DNA codes
- to locate homoplasies
Critical Thinking Questions
Dolphins and fish have similar body shapes. Is this feature more likely a homologous or analogous trait?
Dolphins are mammals and fish are not, which means that their evolutionary paths (phylogenies) are quite separate. Dolphins probably adapted to have a similar body plan after returning to an aquatic lifestyle, and, therefore, this trait is probably analogous.
Why is it so important for scientists to distinguish between homologous and analogous characteristics before building phylogenetic trees?
Phylogenetic trees are based on evolutionary connections. If an analogous similarity were used on a tree, this would be erroneous and, furthermore, would cause the subsequent branches to be inaccurate.
Describe maximum parsimony.
Maximum parsimony hypothesizes that events occurred in the simplest, most obvious way, and the pathway of evolution probably includes the fewest major events that coincide with the evidence at hand.
What we see in the layers of the earth’s crust is better explained by a global flood catastrophe than by the slow, uniformitarianist theories of evolutionists.
Evolutionist scientists tell us that what we view on the earth’s surface, and its crust, is the result of millions (billions) of years of slow, steady deposits of material. The layers of our planet’s outer shell are a result of a plodding process that took a very long period of time. However, there are many features that simply could not have been formed this way and actually make much more sense when attributed to the worldwide flood of Noah’s time. Studies have been done on the effects of the Mt. St. Helen’s eruption on May 18, 1980, that show that landscapes similar to what we see in the Grand Canyon could have been formed in mere minutes instead of thousands, millions, or billions, of years. In other words, there is no reason at all to doubt the biblical record of creation and Noah’s worldwide flood.
Darwin in America
A lmost 160 years after Charles Darwin publicized his groundbreaking theory on the development of life, Americans are still arguing about evolution. In spite of the fact that evolutionary theory is accepted by all but a small number of scientists, it continues to be rejected by many Americans. In fact, about one-in-five U.S. adults reject the basic idea that life on Earth has evolved at all. And roughly half of the U.S. adult population accepts evolutionary theory, but only as an instrument of God’s will.
Most biologists and other scientists contend that evolutionary theory convincingly explains the origins and development of life on Earth. Moreover, they say, a scientific theory is not a hunch or a guess, but is instead an established explanation for a natural phenomenon, like gravity, that has repeatedly been tested and refined through observation and experimentation.
So if evolution is as established in the scientific community as the theory of gravity, why are people still arguing about it more than century and a half after Darwin proposed it? The answer lies, in large part, in the theological implications of evolutionary thinking. For many religious people, the Darwinian view of life – a panorama of brutal struggle and constant change – conflicts with both the biblical creation story and the Judeo-Christian concept of an active, loving God who intervenes in human events. (See “Religious Groups’ Views on Evolution.”)
This basic concern with evolutionary theory has helped drive the decadeslong opposition to teaching it in public schools. Even over the last 15 years, educators, scientists, parents, religious leaders and others in more than a dozen states have engaged in public battles in school boards, legislatures and courts over how school curricula should handle evolution. The issue was even discussed and debated during the runups to the 2000 and 2008 presidential elections. This battle has ebbed in recent years, but it has not completely died out.
Outside the classroom, much of the opposition to evolution has involved its broader social implications and the belief that it can be understood in ways that are socially and politically dangerous. For instance, some social conservatives charge that evolutionary theory serves to strengthen broader arguments that justify practices they vehemently oppose, such as abortion and euthanasia. Evolutionary theory also plays a role in arguments in favor of transhumanism and other efforts to enhance human abilities and extend the human lifespan. Still other evolution opponents say that well-known advocates for atheism, such as Richard Dawkins, view evolutionary theory not just as proof of the folly of religious faith, but also as a justification for various types of discrimination against religion and religious people.
A look back at American history shows that, in many ways, questions about evolution have long served as proxies in larger debates about religious, ethical and social norms. From efforts on the part of some churches in the 19th and early 20th centuries to advance a more liberal form of Christianity, to the more recent push and pull over the roles of religion and science in the public square, attitudes toward evolution have often been used as a fulcrum by one side or the other to try to advance their cause.
Darwin comes to America
In formulating his theory of evolution through natural selection, Charles Darwin did not set out to create a public controversy. In fact, his concerns over how his ideas would be received by the broader public led him to wait more than 20 years to publicize them. He might never have done so if another British naturalist, Alfred Russel Wallace, had not in 1858 independently come up with a very similar theory. At that point, Darwin, who had already shared his conclusions with a small number of fellow scientists, finally revealed his long-held ideas about evolution and natural selection to a wider audience.
Darwin built his theory on four basic premises. First, he argued, each animal is not an exact replica of its parents, but is different in subtle ways. Second, he said, although these differences in each generation are random, some of them convey distinct advantages to an animal, giving it a much greater chance to survive and breed. Over time, this beneficial variation spreads to the rest of the species, because those with the advantage are more likely than those without it to stay alive and reproduce. And, finally, over longer periods of time, cumulative changes produce new species, all of which share a common ancestor. (For more on this, see “Darwin and His Theory of Evolution.”)
In November 1859, Darwin published “On the Origin of Species by Means of Natural Selection,” which laid out his theory in detail. The book became an instant bestseller and, as Darwin had feared, set off a firestorm of controversy in his native Britain. While many scientists defended Darwin, religious leaders and others immediately rejected his theory, not only because it directly contradicted the creation story in the biblical book of Genesis, but also because – on a broader level – it implied that life had developed due to natural processes rather than as the creation of a loving God.
In the United States, which was on the verge of the Civil War, the publication of “Origin” went largely unnoticed. By the 1870s, American religious leaders and thinkers had begun to consider the theological implications of Darwin’s theory. Still, the issue didn’t filter down to the wider American public until the end of the 19th century, when many popular Christian authors and speakers, including the famed Chicago evangelist and missionary Dwight L. Moody, began to inveigh against Darwinism as a threat to biblical truth and public morality.
At the same time, other dramatic shifts were taking place in the country’s religious landscape. From the 1890s to the 1930s, the major American Protestant denominations gradually split into two camps: modernist, or theologically liberal Protestantism (what would become mainline Protestantism) and evangelical, or otherwise theologically conservative, Protestantism.
This schism owed to numerous cultural and intellectual developments of the era, including, but not limited to, the advent of new scientific thinking. Theologians and others also grappled with new questions about the historical accuracy of biblical accounts, as well as a host of provocative and controversial new ideas from such thinkers as Karl Marx and Sigmund Freud about both the individual and society. Modernist Protestants sought to integrate these new theories and ideas, including evolution, into their religious doctrine, while more conservative Protestants resisted them.
By the early 1920s, evolution had become perhaps the most important wedge issue in this Protestant divide, in part because the debate had taken on a pedagogical dimension, with students throughout the nation now studying Darwin’s ideas in biology classes. The issue became a mainstay for Protestant evangelists, including Billy Sunday, the most popular preacher of this era. “I don’t believe the old bastard theory of evolution,” he famously exclaimed during a 1925 revival meeting. But it was William Jennings Bryan, a man of politics, not the cloth, who ultimately became the leader of a full-fledged national crusade against evolution.
Bryan, a populist orator and devout evangelical Protestant who had thrice run unsuccessfully for president, believed that teaching of evolution in the nation’s schools would ensure that whole generations would grow up believing that the Bible was no more than “a collection of myths,” and would undermine the country’s Christian faith in favor of the doctrine of “survival of the fittest.”
Bryan’s fear of social Darwinism was not entirely unfounded. Evolutionary thinking had helped birth the eugenics movement, which maintained that one could breed improved human beings in the same way that farmers breed better sheep and cattle. Eugenics led to now-discredited theories of race and class superiority that helped inspire Nazi ideology in America, some used social Darwinism to argue in favor of restricting immigration (particularly from Southern and Eastern Europe) or to enact state laws requiring sterilization to stop “mental deficients” from having children.
Many who favored the teaching of evolution in public schools did not support eugenics, but simply wanted students to be exposed to the most current scientific thinking. For others, like supporters of the newly formed American Civil Liberties Union, teaching evolution was an issue of freedom of speech as well as a matter of maintaining a separation of church and state. And still others, like famed lawyer Clarence Darrow, saw the battle over evolution as a proxy for a wider cultural conflict between what they saw as progress and modernity on the one side, and religious superstition and backwardness on the other.
Scopes and its aftermath
At the urging of Bryan and evangelical Christian leaders, evolution opponents tried to ban the teaching of Darwin’s theory in a number of states. Although early legislative efforts failed, evolution opponents won a victory in 1925 when the Tennessee Legislature overwhelmingly approved legislation making it a crime to teach “any theory that denies the story of the Divine Creation of man as taught in the Bible.” Soon after the Tennessee law was enacted, the ACLU offered to defend any science teacher in the state who was willing to break it. John Scopes, a teacher in the small, rural town of Dayton, Tennessee, agreed to take up the ACLU’s offer.
The subsequent trial popularly referred to as the Scopes “monkey” trial, was one of the first true media trials of the modern era, covered in hundreds of newspapers and broadcast live on the radio. Defending Scopes was Darrow, then the most famous lawyer in the country. And joining state prosecutors was Bryan. From the start, both sides seemed to agree that the case was being tried more in the court of public opinion than in a court of law.
As the trial progressed, it seemed increasingly clear that Darrow’s hope of spurring public debate over the merits of teaching evolution was being stymied by state prosecutors. But then Darrow made the highly unorthodox request of calling Bryan to the witness stand. Although the politician was under no obligation to testify, he acceded to Darrow’s invitation.
With Bryan on the stand, Darrow proceeded to ask a series of detailed questions about biblical events that could be seen as inconsistent, unreal or both. For instance, Darrow asked, how could there be morning and evening during the first three days of biblical creation if the sun was not formed until the fourth? Bryan responded to this and similar questions in different ways. Often, he defended the biblical account in question as the literal truth. On other occasions, however, he admitted that parts of the Bible might need to be interpreted in order to be fully understood.
Scopes was convicted of violating the anti-evolution law and fined, although his conviction was later overturned by the Tennessee Supreme Court on a technicality. But the verdict was largely irrelevant to the broader debate. The trial, particularly Darrow’s questioning of Bryan, created a tremendous amount of positive publicity for the pro-evolution camp, especially in northern urban areas, where the media and cultural elites were sympathetic toward Scopes and his defense.
At the same time, this post-Scopes momentum did not destroy the anti-evolution movement. Indeed, in the years immediately following Scopes, the Mississippi and Arkansas state legislatures enacted bills similar to Tennessee’s. Other states, particularly in the South and Midwest, passed resolutions condemning the inclusion of material on evolution in biology textbooks. These actions, along with a patchwork of restrictions from local school boards, prompted most publishers to remove references to Darwin from their science textbooks.
Efforts to make evolution the standard in all biology classes stalled, due largely to the fact that the government prohibition on religious establishment or favoritism, found in the establishment clause of the First Amendment to the U.S. Constitution, applied at the time only to federal and not state actions. State governments could set their own policies on church-state issues. Only in 1947, with the Supreme Court’s decision in Everson v. Board of Education, did the constitutional prohibition on religious establishment begin to apply to state as well as federal actions. Evolution proponents also received a boost a decade after Everson, in 1957, when the Soviet launch of the first satellite, Sputnik I, prompted the United States to make science education a national priority.
Meanwhile, beginning in the late 1960s, the U.S. Supreme Court issued a number of important decisions that imposed severe restrictions on state governments that opposed the teaching of evolution. In 1968, in Epperson v. Arkansas, the high court unanimously struck down as unconstitutional an Arkansas law banning the teaching of evolution in public schools. Specifically, the justices said, the law violated the First Amendment’s establishment clause because it sought to prevent students from learning a particular viewpoint antithetical to conservative Christianity, and thus promoted religion.
Almost 20 years after Epperson, the court issued another key ruling, this time involving the teaching of “creation science” in public schools. Proponents of creation science contend that the weight of scientific evidence supports the creation story as described in the biblical book of Genesis, with the formation of Earth and the development of life occurring in six 24-hour days. The presence of fossils and evidence of significant geological change are attributed to the catastrophic flood described in the eighth chapter of Genesis.
In Edwards v. Aguillard (1987), the high court struck down a Louisiana law requiring public schools to teach “creation science” alongside evolution, ruling (as in Epperson) that the statute violated the establishment clause because its aim was to promote religion. (For more on the legal aspects of the evolution debate, see “The Social and Legal Dimensions of the Evolution Debate in the U.S.”)
Partly due to these and other court decisions, opposition to teaching evolution itself evolved, with opponents changing their goals and tactics. In the first decade of the 21st century, for instance, some local and state school boards mandated the teaching of what they argued were scientific alternatives to evolution – notably the concept of “intelligent design,” which posits that life is too complex to have developed without the intervention of an outside, possibly divine, force. While rejected by most scientists as creationism cloaked in scientific language, supporters of intelligent design cite what they call “irreducibly complex” systems (such as the eye or the process by which blood clots) as proof that Darwinian evolution is not an adequate explanation for the development of life.
But efforts to inject intelligent design into public school science curricula met the same fate as creation science had decades earlier. Once again, courts ruled that intelligent design is a religious argument, not science, and thus couldn’t be taught in public schools. Other efforts to require schools to teach critiques of evolution or to mandate that students listen to or read evolution disclaimers also were struck down.
In the years following these court decisions, there have been new efforts in Texas, Tennessee, Kansas and other states to challenge the presence of evolutionary theory in public school science curricula. For instance, in 2017, the South Dakota Senate passed legislation that would allow teachers in the state’s public schools to present students with both the strengths and weaknesses of scientific information. The measure, which critics claimed was clearly aimed at critiquing evolution, ultimately stalled in the state’s House of Representatives. And in 2018, an internal review at the Arizona State Board of Education led to an unsuccessful effort to dilute references to evolution in the state’s science standards.
Title photo: Famed attorney Clarence Darrow makes a point at the “Scopes Monkey Trial” in 1925. Darrow defended teacher John Scopes, who had run afoul of Tennessee’s law against teaching evolution in public schools. (Bettmann Archive/Getty Images)
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Life, Here and Beyond
Ask most any American whether life exists on other planets and moons, and the answer you’ll get is a confident “yes!” Going back decades (and in many ways generations), we’ve been introduced to a menagerie of extraterrestrials good and bad. Their presence suffuses our entertainment and culture, and we humans seem to have an almost innate belief-or is it a hope-that we are not alone in the universe.
But that extraterrestrial presence on regular display is, of course, a fiction. No life beyond Earth has ever been found there is no evidence that alien life has ever visited our planet. It’s all a story.
This does not mean, however, that the universe is lifeless. While no clear signs of life have ever been detected, the possibility of extraterrestrial biology – the scientific logic that supports it – has grown increasingly plausible. That is perhaps the single largest achievement of the burgeoning field of astrobiology, the broad-based study of the origins of life here and the search for life beyond Earth.
By exploring and illuminating the world of extreme life on Earth, by experimenting with how life here began, by understanding more about the chemical makeup of the cosmos, by testing for habitability on missions to Mars, Saturn’s moon Titan, and beyond, an enormous body of science has already been assembled to analyze and explain the origins, characteristics and possible extraterrestrial dimensions of life. And unlike the ETs and star-ship invaders of popular culture, these discoveries are real.
Turning Science Fiction into Science Fact
Consider: The rover Curiosity has firmly determined that ancient Mars was significantly more wet and warm, and was an entirely habitable place for microbial life. All the ingredients needed for life as we know it – the proper chemicals, a consistent source of energy, and water that was likely present and stable on the surface for millions of years – were clearly present.
Did microbial life then begin? If so, did it evolve? Those questions remain unanswered, but this much is known: If a second genesis occurred on Mars (or on Jupiter’s moon Europa, Saturn’s moon Enceladus, or anywhere else in our solar system), then the likelihood increases substantially that many other forms of life exist on those billions of exoplanets and exomoons now known to orbit distant stars and planets. One origin of life on Earth could be the result of a remarkable and inexplicable pathway to life. Two origins in one solar system strongly suggests that life is commonplace in the universe.
Consider, too, the revolution in understanding that has taken place since the mid-1990s regarding planets and moons in solar systems well beyond ours. Since ancient times, natural philosophers, then scientists, and untold interested others predicted, assumed even, that many other planets orbited their stars. By now thousands of exoplanets have been officially identified – via NASA missions like Kepler as well as ground-based observations — and billions more await discovery. And that’s just in our Milky Way galaxy.
With advances in the instruments and knowledge that make possible the exoplanet hunt, the focus has been increasing refined to identify planets lying in habitable zones – at distances from their stars that would allow water to remain at least periodically liquid on a planet’s surface. The search for exoplanets was born in the fields of astronomy and astrophysics, but it has always been intertwined with astrobiology as well. As with so many NASA missions, the broad and intense drive to find and understand habitable zone planets and moons both greatly enhances astrobiology and is informed by astrobiology.
Our experience with finding distant planets also makes you wonder: Will the search for the current or past presence of extraterrestrial life some day be viewed as a parallel to the earlier search for exoplanets? Men and women of science, as well as the lay public, intuitively assumed planets existed beyond our solar system, but these planets were identified only when our technology and thinking had sufficiently advanced. Is the discovery of ET life similarly awaiting our coming of scientific age?
The Past As a Guide to the Future
Astrobiology research is taking place because its time has come. Scientists across the country and around the world are diving into origin-of-life and life-beyond-Earth issues and developing exciting and cutting edge work. But NASA also has an astrobiology “strategy” describing where the agency sees promising lines of research – from the highly specific to the wide and broad — that the agency might support. A sampling of examples:
• What were the steps that led inanimate materials – rocks, sediments, organic compounds, water – to come together and build living organisms, with replicating genes, cell walls, and the ability to reproduce?
• What led to the proliferation of new life forms on Earth?
• How do water and essential organic compounds arrive on planets and moons, and how do they interact with the planets and moons they land on?
• Is it possible to learn from chemicals and minerals on the surface of planets whether microbes might live there, including beneath the planet’s surface?
• Is it possible, likely even, that life exists elsewhere based on elements other than carbon and a system different than DNA ? Could such life even exist here on Earth, but is as yet undetected?
A New Physics Theory of Life
An MIT physicist has proposed the provocative idea that life exists because the law of increasing entropy drives matter to acquire lifelike physical properties.
Jeremy England, a 31-year-old physicist at MIT, thinks he has found the underlying physics driving the origin and evolution of life.
Katherine Taylor for Quanta Magazine
Popular hypotheses credit a primordial soup, a bolt of lightning and a colossal stroke of luck. But if a provocative new theory is correct, luck may have little to do with it. Instead, according to the physicist proposing the idea, the origin and subsequent evolution of life follow from the fundamental laws of nature and “should be as unsurprising as rocks rolling downhill.”
From the standpoint of physics, there is one essential difference between living things and inanimate clumps of carbon atoms: The former tend to be much better at capturing energy from their environment and dissipating that energy as heat. Jeremy England, a 31-year-old assistant professor at the Massachusetts Institute of Technology, has derived a mathematical formula that he believes explains this capacity. The formula, based on established physics, indicates that when a group of atoms is driven by an external source of energy (like the sun or chemical fuel) and surrounded by a heat bath (like the ocean or atmosphere), it will often gradually restructure itself in order to dissipate increasingly more energy. This could mean that under certain conditions, matter inexorably acquires the key physical attribute associated with life.
“You start with a random clump of atoms, and if you shine light on it for long enough, it should not be so surprising that you get a plant,” England said.
England’s theory is meant to underlie, rather than replace, Darwin’s theory of evolution by natural selection, which provides a powerful description of life at the level of genes and populations. “I am certainly not saying that Darwinian ideas are wrong,” he explained. “On the contrary, I am just saying that from the perspective of the physics, you might call Darwinian evolution a special case of a more general phenomenon.”
His idea, detailed in a recent paper and further elaborated in a talk he is delivering at universities around the world, has sparked controversy among his colleagues, who see it as either tenuous or a potential breakthrough, or both.
England has taken “a very brave and very important step,” said Alexander Grosberg, a professor of physics at New York University who has followed England’s work since its early stages. The “big hope” is that he has identified the underlying physical principle driving the origin and evolution of life, Grosberg said.
“Jeremy is just about the brightest young scientist I ever came across,” said Attila Szabo, a biophysicist in the Laboratory of Chemical Physics at the National Institutes of Health who corresponded with England about his theory after meeting him at a conference. “I was struck by the originality of the ideas.”
Others, such as Eugene Shakhnovich, a professor of chemistry, chemical biology and biophysics at Harvard University, are not convinced. “Jeremy’s ideas are interesting and potentially promising, but at this point are extremely speculative, especially as applied to life phenomena,” Shakhnovich said.
England’s theoretical results are generally considered valid. It is his interpretation — that his formula represents the driving force behind a class of phenomena in nature that includes life — that remains unproven. But already, there are ideas about how to test that interpretation in the lab.
“He’s trying something radically different,” said Mara Prentiss, a professor of physics at Harvard who is contemplating such an experiment after learning about England’s work. “As an organizing lens, I think he has a fabulous idea. Right or wrong, it’s going to be very much worth the investigation.”
At the heart of England’s idea is the second law of thermodynamics, also known as the law of increasing entropy or the “arrow of time.” Hot things cool down, gas diffuses through air, eggs scramble but never spontaneously unscramble in short, energy tends to disperse or spread out as time progresses. Entropy is a measure of this tendency, quantifying how dispersed the energy is among the particles in a system, and how diffuse those particles are throughout space. It increases as a simple matter of probability: There are more ways for energy to be spread out than for it to be concentrated. Thus, as particles in a system move around and interact, they will, through sheer chance, tend to adopt configurations in which the energy is spread out. Eventually, the system arrives at a state of maximum entropy called “thermodynamic equilibrium,” in which energy is uniformly distributed. A cup of coffee and the room it sits in become the same temperature, for example. As long as the cup and the room are left alone, this process is irreversible. The coffee never spontaneously heats up again because the odds are overwhelmingly stacked against so much of the room’s energy randomly concentrating in its atoms.
Although entropy must increase over time in an isolated or “closed” system, an “open” system can keep its entropy low — that is, divide energy unevenly among its atoms — by greatly increasing the entropy of its surroundings. In his influential 1944 monograph “What Is Life?” the eminent quantum physicist Erwin Schrödinger argued that this is what living things must do. A plant, for example, absorbs extremely energetic sunlight, uses it to build sugars, and ejects infrared light, a much less concentrated form of energy. The overall entropy of the universe increases during photosynthesis as the sunlight dissipates, even as the plant prevents itself from decaying by maintaining an orderly internal structure.
Life does not violate the second law of thermodynamics, but until recently, physicists were unable to use thermodynamics to explain why it should arise in the first place. In Schrödinger’s day, they could solve the equations of thermodynamics only for closed systems in equilibrium. In the 1960s, the Belgian physicist Ilya Prigogine made progress on predicting the behavior of open systems weakly driven by external energy sources (for which he won the 1977 Nobel Prize in chemistry). But the behavior of systems that are far from equilibrium, which are connected to the outside environment and strongly driven by external sources of energy, could not be predicted.
This situation changed in the late 1990s, due primarily to the work of Chris Jarzynski, now at the University of Maryland, and Gavin Crooks, now at Lawrence Berkeley National Laboratory. Jarzynski and Crooks showed that the entropy produced by a thermodynamic process, such as the cooling of a cup of coffee, corresponds to a simple ratio: the probability that the atoms will undergo that process divided by their probability of undergoing the reverse process (that is, spontaneously interacting in such a way that the coffee warms up). As entropy production increases, so does this ratio: A system’s behavior becomes more and more “irreversible.” The simple yet rigorous formula could in principle be applied to any thermodynamic process, no matter how fast or far from equilibrium. “Our understanding of far-from-equilibrium statistical mechanics greatly improved,” Grosberg said. England, who is trained in both biochemistry and physics, started his own lab at MIT two years ago and decided to apply the new knowledge of statistical physics to biology.
Using Jarzynski and Crooks’ formulation, he derived a generalization of the second law of thermodynamics that holds for systems of particles with certain characteristics: The systems are strongly driven by an external energy source such as an electromagnetic wave, and they can dump heat into a surrounding bath. This class of systems includes all living things. England then determined how such systems tend to evolve over time as they increase their irreversibility. “We can show very simply from the formula that the more likely evolutionary outcomes are going to be the ones that absorbed and dissipated more energy from the environment’s external drives on the way to getting there,” he said. The finding makes intuitive sense: Particles tend to dissipate more energy when they resonate with a driving force, or move in the direction it is pushing them, and they are more likely to move in that direction than any other at any given moment.
“This means clumps of atoms surrounded by a bath at some temperature, like the atmosphere or the ocean, should tend over time to arrange themselves to resonate better and better with the sources of mechanical, electromagnetic or chemical work in their environments,” England explained.
Self-replication (or reproduction, in biological terms), the process that drives the evolution of life on Earth, is one such mechanism by which a system might dissipate an increasing amount of energy over time. As England put it, “A great way of dissipating more is to make more copies of yourself.” In a September paper in the Journal of Chemical Physics, he reported the theoretical minimum amount of dissipation that can occur during the self-replication of RNA molecules and bacterial cells, and showed that it is very close to the actual amounts these systems dissipate when replicating. He also showed that RNA, the nucleic acid that many scientists believe served as the precursor to DNA-based life, is a particularly cheap building material. Once RNA arose, he argues, its “Darwinian takeover” was perhaps not surprising.
The chemistry of the primordial soup, random mutations, geography, catastrophic events and countless other factors have contributed to the fine details of Earth’s diverse flora and fauna. But according to England’s theory, the underlying principle driving the whole process is dissipation-driven adaptation of matter.
This principle would apply to inanimate matter as well. “It is very tempting to speculate about what phenomena in nature we can now fit under this big tent of dissipation-driven adaptive organization,” England said. “Many examples could just be right under our nose, but because we haven’t been looking for them we haven’t noticed them.”
Scientists have already observed self-replication in nonliving systems. According to new research led by Philip Marcus of the University of California, Berkeley, and reported in Physical Review Letters in August, vortices in turbulent fluids spontaneously replicate themselves by drawing energy from shear in the surrounding fluid. And in a paper appearing online this week in Proceedings of the National Academy of Sciences, Michael Brenner, a professor of applied mathematics and physics at Harvard, and his collaborators present theoretical models and simulations of microstructures that self-replicate. These clusters of specially coated microspheres dissipate energy by roping nearby spheres into forming identical clusters. “This connects very much to what Jeremy is saying,” Brenner said.
Besides self-replication, greater structural organization is another means by which strongly driven systems ramp up their ability to dissipate energy. A plant, for example, is much better at capturing and routing solar energy through itself than an unstructured heap of carbon atoms. Thus, England argues that under certain conditions, matter will spontaneously self-organize. This tendency could account for the internal order of living things and of many inanimate structures as well. “Snowflakes, sand dunes and turbulent vortices all have in common that they are strikingly patterned structures that emerge in many-particle systems driven by some dissipative process,” he said. Condensation, wind and viscous drag are the relevant processes in these particular cases.
“He is making me think that the distinction between living and nonliving matter is not sharp,” said Carl Franck, a biological physicist at Cornell University, in an email. “I’m particularly impressed by this notion when one considers systems as small as chemical circuits involving a few biomolecules.”
England’s bold idea will likely face close scrutiny in the coming years. He is currently running computer simulations to test his theory that systems of particles adapt their structures to become better at dissipating energy. The next step will be to run experiments on living systems.
Prentiss, who runs an experimental biophysics lab at Harvard, says England’s theory could be tested by comparing cells with different mutations and looking for a correlation between the amount of energy the cells dissipate and their replication rates. “One has to be careful because any mutation might do many things,” she said. “But if one kept doing many of these experiments on different systems and if [dissipation and replication success] are indeed correlated, that would suggest this is the correct organizing principle.”
Brenner said he hopes to connect England’s theory to his own microsphere constructions and determine whether the theory correctly predicts which self-replication and self-assembly processes can occur — “a fundamental question in science,” he said.
Having an overarching principle of life and evolution would give researchers a broader perspective on the emergence of structure and function in living things, many of the researchers said. “Natural selection doesn’t explain certain characteristics,” said Ard Louis, a biophysicist at Oxford University, in an email. These characteristics include a heritable change to gene expression called methylation, increases in complexity in the absence of natural selection, and certain molecular changes Louis has recently studied.
If England’s approach stands up to more testing, it could further liberate biologists from seeking a Darwinian explanation for every adaptation and allow them to think more generally in terms of dissipation-driven organization. They might find, for example, that “the reason that an organism shows characteristic X rather than Y may not be because X is more fit than Y, but because physical constraints make it easier for X to evolve than for Y to evolve,” Louis said.
“People often get stuck in thinking about individual problems,” Prentiss said. Whether or not England’s ideas turn out to be exactly right, she said, “thinking more broadly is where many scientific breakthroughs are made.”
Correction: This article was revised on January 22, 2014, to reflect that Ilya Prigogine won the Nobel Prize in chemistry, not physics.
Why Science Does Not Disprove God
A number of recent books and articles would have you believe that&mdashsomehow&mdashscience has now disproved the existence of God. We know so much about how the universe works, their authors claim, that God is simply unnecessary: we can explain all the workings of the universe without the need for a Creator.
And indeed, science has brought us an immense amount of understanding. The sum total of human knowledge doubles roughly every couple of years or less. In physics and cosmology, we can now claim to know what happened to our universe as early as a tiny fraction of a second after the Big Bang, something that may seem astounding. In chemistry, we understand the most complicated reactions among atoms and molecules, and in biology we know how the living cell works and have mapped out our entire genome. But does this vast knowledge base disprove the existence of some kind of pre-existent outside force that may have launched our universe on its way?
Science won major victories against entrenched religious dogma throughout the 19th century. In the 1800s, discoveries of Neanderthal remains in Belgium, Gibraltar and Germany showed that humans were not the only hominids to occupy earth, and fossils and remains of now extinct animals and plants further demonstrated that flora and fauna evolve, live for millennia and then sometimes die off, ceding their place on the planet to better-adapted species. These discoveries lent strong support to the then emerging theory of evolution, published by Charles Darwin in 1859. And in 1851, Leon Foucault, a self-trained French physicist, proved definitively that earth rotates&mdashrather than staying in place as the sun revolved around it&mdashusing a special pendulum whose circular motion revealed the planet&rsquos rotation. Geological discoveries made over the same century devastated the &ldquoyoung earth&rdquo hypothesis. We now know that earth is billions, not thousands, of years old, as some theologians had calculated based on counting generations back to the biblical Adam. All of these discoveries defeated literal interpretations of Scripture.
But has modern science, from the beginning of the 20th century, proved that there is no God, as some commentators now claim? Science is an amazing, wonderful undertaking: it teaches us about life, the world and the universe. But it has not revealed to us why the universe came into existence nor what preceded its birth in the Big Bang. Biological evolution has not brought us the slightest understanding of how the first living organisms emerged from inanimate matter on this planet and how the advanced eukaryotic cells&mdashthe highly structured building blocks of advanced life forms&mdashever emerged from simpler organisms. Neither does it explain one of the greatest mysteries of science: how did consciousness arise in living things? Where do symbolic thinking and self-awareness come from? What is it that allows humans to understand the mysteries of biology, physics, mathematics, engineering and medicine? And what enables us to create great works of art, music, architecture and literature? Science is nowhere near to explaining these deep mysteries.
But much more important than these conundrums is the persistent question of the fine-tuning of the parameters of the universe: Why is our universe so precisely tailor-made for the emergence of life? This question has never been answered satisfactorily, and I believe that it will never find a scientific solution. For the deeper we delve into the mysteries of physics and cosmology, the more the universe appears to be intricate and incredibly complex. To explain the quantum-mechanical behavior of even one tiny particle requires pages and pages of extremely advanced mathematics. Why are even the tiniest particles of matter so unbelievably complicated? It appears that there is a vast, hidden &ldquowisdom,&rdquo or structure, or knotty blueprint for even the most simple-looking element of nature. And the situation becomes much more daunting as we expand our view to the entire cosmos.
We know that 13.7 billion years ago, a gargantuan burst of energy, whose nature and source are completely unknown to us and not in the least understood by science, initiated the creation of our universe. Then suddenly, as if by magic, the &ldquoGod particle&rdquo&mdashthe Higgs boson discovered two years ago inside CERN&rsquos powerful particle accelerator, the Large Hadron Collider&mdashcame into being and miraculously gave the universe its mass. Why did this happen? The mass constituted elementary particles&mdashthe quarks and the electron&mdashwhose weights and electrical charges had to fall within immeasurably tight bounds for what would happen next. For from within the primeval soup of elementary particles that constituted the young universe, again as if by a magic hand, all the quarks suddenly bunched in threes to form protons and neutrons, their electrical charges set precisely to the exact level needed to attract and capture the electrons, which then began to circle nuclei made of the protons and neutrons. All of the masses, charges and forces of interaction in the universe had to be in just the precisely needed amounts so that early light atoms could form. Larger ones would then be cooked in nuclear fires inside stars, giving us carbon, iron, nitrogen, oxygen and all the other elements that are so essential for life to emerge. And eventually, the highly complicated double-helix molecule, the life-propagating DNA, would be formed.
Why did everything we need in order to exist come into being? How was all of this possible without some latent outside power to orchestrate the precise dance of elementary particles required for the creation of all the essentials of life? The great British mathematician Roger Penrose has calculated&mdashbased on only one of the hundreds of parameters of the physical universe&mdashthat the probability of the emergence of a life-giving cosmos was 1 divided by 10, raised to the power 10, and again raised to the power of 123. This is a number as close to zero as anyone has ever imagined. (The probability is much, much smaller than that of winning the Mega Millions jackpot for more days than the universe has been in existence.)
The scientific atheists have scrambled to explain this troubling mystery by suggesting the existence of a multiverse&mdashan infinite set of universes, each with its own parameters. In some universes, the conditions are wrong for life however, by the sheer size of this putative multiverse, there must be a universe where everything is right. But if it takes an immense power of nature to create one universe, then how much more powerful would that force have to be in order to create infinitely many universes? So the purely hypothetical multiverse does not solve the problem of God. The incredible fine-tuning of the universe presents the most powerful argument for the existence of an immanent creative entity we may well call God. Lacking convincing scientific evidence to the contrary, such a power may be necessary to force all the parameters we need for our existence&mdashcosmological, physical, chemical, biological and cognitive&mdashto be what they are.
Science and religion are two sides of the same deep human impulse to understand the world, to know our place in it, and to marvel at the wonder of life and the infinite cosmos we are surrounded by. Let&rsquos keep them that way, and not let one attempt to usurp the role of the other.