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The Death of Natural Selection

The views expressed are those of the author and are not necessarily those of Scientific American.


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My evening plan to read Harry Potter for the first time (I know!) was thwarted by Linton Weeks’s thought-provoking post on the right of plants to evolve. The post reports on the work of the Community Environmental Legal Defense Fund, a nonprofit that helps communities develop laws that recognize ecosystems as rights-bearing entities. The CELDF’s work is not unprecedented; in 2008 Ecuador granted nature the constitutional right to the maintenance and regeneration of its evolutionary processes. The associate director of CELDF explained: “fish and other species in a river may be recognized as having the right to exist and evolve.”

These are not the only efforts to protect species’ abilities to evolve. The International Union for the Conservation of Nature (IUCN), for example, defines wilderness areas as “protecting large mainly untouched areas where ecosystem processes, including evolution, can continue unhindered by human[s], including development or mass tourism.” Other environmental organizations are similarly concerned about species’ evolutionary opportunities.

That environmentalists are pursuing legal protection of nature’s right to evolve suggests that nature’s ability to evolve could be threatened or withheld. Can humans really stop evolution?

Darwin wouldn’t think so. In On the Origin of Species, he wrote:

It may be said that natural selection is daily and hourly scrutinizing throughout the world, every variation, even the slightest; rejecting that which is bad, preserving and adding up all that is good; silently and insensibly working, whenever and wherever opportunity offers, at the improvement of each organic being in relation to its organic and inorganic conditions of life.

Species are constantly evolving to changes in their environments. “Right to evolve” proponents are arguing something more specific, that species should have the right to evolve under certain environmental conditions. This contention prompts monstrous scientific and philosophical questions. Do species have the right to evolve without human interference? To undergo natural selection, not artificial selection? Is it even possible for humans to avoid affecting the evolutionary trajectories of other species?

Humans have long recognized their ability to select for certain traits in other species. Artificial selection, or selective breeding, explains the proliferation of domesticated plants and animals. It explains the difference between a Great Dane and Paris Hilton’s Chihuahua. Darwin used the familiarity of artificial selection to make his case for “natural selection” – the ability of biotic and abiotic non-humans to select for certain traits in other species.

If it profit a plant to have its seeds more and more widely disseminated by the wind, I can see no greater difficulty in this being effected through natural selection, than in the cotton-planter increasing and improving by selection the down in the pods on his cotton-trees.

But Darwin, and the scientists who followed him, believed that artificial selection occurred much more rapidly than natural selection:

We see nothing of these slow changes[of natural selection] in progress, until the hand of time has marked the long lapse of ages, and then so imperfect is our view into long past geological ages, that we only see that the forms of life are now different from what they formerly were.

Recent research in ecology and evolution refutes this idea. In one experiment, ecologists found that in the absence of insect herbivores, evening primroses evolved to flower earlier and produce less defensive compounds in only three generations. Such “rapid evolution” has also been observed in organisms ranging from zooplankton to soapberry bugs to finches. It seems that populations sometimes respond to selective forces in just a few generations.

The second way that Darwin distinguished natural selection from artificial selection was by the quality of its products. In his view, humans necessarily produced species of lesser quality than God’s Nature. He valued the art of nature over the artifice of humans:

How fleeting are the wishes and efforts of man! how short his time! and consequently how poor will his products be, compared with those accumulated by nature during whole geological periods.

Like Darwin, many environmentalists value the work of nature over the work of humans. Perhaps this explains their concern for species’ access to “natural” conditions – meaning conditions without humans – and, presumably, access to natural selection. In this context “artificial” selection has a negative connotation: artificial in the sense of a mimicked or inferior product. People love their Chihuahuas and tulips, and benefit from their corn and cows, but they want to protect the evolutionary autonomy of polar bears and narwhal whales.

This sounds fine. It sounds sensible, given our familiar categories: natural versus artificial, human versus nature, Chihuahua versus polar bear.

But is there a species, anywhere, with an evolutionary trajectory that has not been affected by humans?

If climate change is caused by humans, then no organisms can avoid selection resulting from human actions. Climate change impacts every corner of the globe. And species evolve in turn.

It is even difficult to take the human impact out of classic examples of natural selection. Take Wikipedia’s entry on natural selection:

A well-known example of natural selection in action is the development of antibiotic resistance in microorganisms.

Tricky. Humans created the selective force (antibiotics) and applied them to microorganisms. It seems the distinction between natural selection and artificial selection is a distinction between unintended and intended design. In the antibiotic example, antibiotics led to selective elimination of maladapted individuals from a larger population. Similarly, in the evening primrose example, ecologists removed insect herbivores from the plants, then the plants responded to the lack of herbivory. In the Chihuahua example, humans picked the Chihuahuas they liked best and bred them. The results of the antibiotic and primrose examples were not intended by humans. The results of the Chihuahua example were.

Few experiments directly compare the results of intended and unintended selection on one organism. (But see this one). Such comparisons could help ecologists better understand evolutionary processes and could help conservationists develop species that are better adapted to climate change or other stressors. Many environmental organizations already emphasize that genetic diversity will be important to species’ evolutionary potentials, and hence odds of survival. Why not breed for climate change resistant species?

The National Center for Science Education states that “The only difference between natural selection and artificial selection is whether the difference in reproductive success is driven by naturally occurring processes, or whether the selection is imposed by humans.” But microorganisms, and Chihuahuas, and even narwhal whales, are acted upon by many concurrent selective forces. Human actions constitute some of those forces, whether they are intended or not.

Unlike Darwin, who believed that humans’ creative powers were trivial compared to Nature’s, environmentalists believe that humans’ creative powers are unique; they believe that humans are so powerful and strange that their capacity to influence other species’ evolutionary trajectories surpasses the capacities of all other abiotic and biotic earthforms combined.

In the state park near my house in New York, deer prosper, favored by suburban development and the extirpation of large predators. These deer decimate plants in the forest understory. Changes in the plant community lead to changes in the animal community. Japanese stiltgrass and Norway maples compete with the trilliums and white oaks. European Starlings fly overhead, first brought to North America in 1890 by a man who wanted to introduce every bird species mentioned in the works of William Shakespeare. A neighbor walks by; his Chihuahua stops to relieve himself on the side of the trail.

The evolutionary trajectory of every species in my local park is affected both by the actions of humans and the actions of non-humans. We cannot deny the reality or the responsibility of being a part of other species’ environments, just as other species are a part of ours.

Should we despair that we cannot enforce another species’ right to evolve without us? Should we abandon all natural areas, seeing them as corrupted shells of what they should be? Or should we embrace our creative potentials, the potentials we share with the rest of the living and nonliving world.

We couldn’t avoid affecting the evolutionary trajectories of other organisms, even if we tried.

Laura Jane Martin About the Author: Laura Jane Martin is a poet, essayist, and NSF graduate fellow at Cornell University, where she studies the ecology and evolution of wetland plants. She has a BS in Biophysics from Brown University. Find more of her work at ljanemartin.com. Follow on Twitter @Laura_J_Martin.

The views expressed are those of the author and are not necessarily those of Scientific American.






Comments 25 Comments

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  1. 1. PleonasticAxiom 12:17 pm 11/5/2012

    Thank you for this article. Anyone who holds humans above natural selection, honestly has no place in the scientific community and needs to be reschooled. I understand this view can be dangerous, but that’s because it’s hypocritical.

    I wonder how this view will change once we start letting man-made software design efficiency for us. We already have “AIs” that can process out through trial-and-error the best way to use what they have.

    Link to this
  2. 2. PleonasticAxiom 12:17 pm 11/5/2012

    Thank you for this article. Anyone who holds humans above natural selection, honestly has no place in the scientific community and needs to be reschooled. I understand this view can be dangerous, but that’s because it’s hypocritical.

    I wonder how this view will change once we start letting man-made software design efficiency for us. We already have “AIs” that can process out through trial-and-error the best way to use what they have.

    Link to this
  3. 3. Heteromeles 12:29 pm 11/5/2012

    Trajectory? I think the biggest problem is thinking there’s a trajectory to evolution, a process which depends to a huge degree on random processes.

    Two points: in evolution, WE are the next frontier. By that, I mean that we’re creating huge, simple, resource rich systems, otherwise known as farms, parks, cities, and the bodies of ourselves and our symbionts (fine, call them domesticated, make up a special word for them). Anything that can take advantage of these resources prospers enormously, and we spend billions each year fighting them. We call them pests, pathogens, and parasites. Or weeds.

    Now, sensible people are for conservation. Why? If you have to conserve it, it means you can kill it. It means that it’s part of a system we humans have adapted to do extremely well in. Perhaps we do too well in it. However, if we don’t do conservation, we create the system above, where we’re the luscious reward and we’re fighting a defensive action against everything that’s evolving furiously to keep taking advantage of us.

    I don’t particularly like that game, myself. Still, making things simple has always appealed to our lazy instincts, which is why so many have gotten rich telling others how to be lazy. It’s a trap, of course, not that we can get out of it now.

    So anyway, conserve. It’s about saving future possibilities for systems we can live with. The alternative is worse.

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  4. 4. MadScientist72 1:26 pm 11/5/2012

    This whole “right to evolve” schtick sounds like a thinly veiled attempt to ban GMOs.
    Natural selection is NOT “dead”, and never will be as long as life exists. Artificial selection, on the other hand, has never been “alive”. It’s just a product of the fallacious notion that humans somehow exist outside of nature.
    Evolution is all about adaptation. Organisms that can’t adapt fail, those that can succeed and those that are the most adaptable are the most successful. The ultimate in adaptation is the ability to alter your environment to suit you, so anyone trying to stop humans from changing the environment is trying to stifle OUR evolution.

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  5. 5. Bops 2:41 pm 11/5/2012

    We need to find different balances so that nature and man can make it to the future successfully. That’s Smart thinking.

    Bad people dominate! Good people work it out, so that both sides move ahead.

    The ultimate in adaptation…talk is from Hitler. Shame on you. We all know how that ends up.

    I don’t know if this has anything to do with Monsanto. I don’t think the food produced from these GMO seeds are even fit for animal feed.

    When I looked up Monsanto, how the plants repel bugs, weed killers, all the farmers suede for seed copy-writes, all the articles I read made me feel sick. Are you a paid Monsanto propaganda person? You need to read more about the after effects the plants are causing to people. They are not tested long enough to be safe before they are even planted. Soybean is a good example…look it up for yourself.

    Too many people are having problems with foods causing acid reflex, allergy and cancer. These seeds make the plants taste bitter. Bitter taste is almost always a signal for toxic. Look up all the foods for yourself. These seeds make plants less digestible. Oral food allergy was almost unheard of a few years ago. Not so now. Babies and little kids are taking acid meds. The schools have to have a peanut allergy table because the problem is getting so bad. Where does this root go to? Monsanto and their other companies were suede for advertising that RoundUp and the other weed and pest killers were as safe as table salt. (Salt is toxic in excess) When a lot of people start to notice problems with the plants, the company is at fault.

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  6. 6. Bops 2:50 pm 11/5/2012

    Heteromeles,

    The problem with trying to keep it anything simple, is that at anytime it can get very complicated. Changing seed might be ok, but not so that we can use more chemicals.

    Link to this
  7. 7. Perisoreus 3:36 pm 11/5/2012

    While I think that trying to include ecosystems or species into the legal system, I am rather opposed to the idea of dividing between “artificial” and “natural” selection. There is no such distinction between “nature” and “human”, at least not beyond the realms of western philosophy and surely not within the world out there.

    As is vividly demonstrated in the course of the article, both concepts, “nature” and “man-made” become highly blurry when applied to reality. This is not to say that human action is without consequences and nonhuman processes do not affect humans but rather quite the contrary. Unlike the opening question suggests (and as #4 already implied), there is no and never has been a way of dividing empirically between nature and man.

    The distinction nevertheless has its benefits, for example when argueing against Monsanto or oil companies by referring to a sacredness or autonomy of nature. It is then an efficient weapon because it goes widely unquestioned; but it can backfire as well as can be observed in the gen food case where it hinders a real critique of Monsanto’s business practices. The point is not that genetic engineering is a crime againts nature (it is not) or potentially dangerous (it is no more than conventional farming) but that Monsanto uses the distinction between nature and man to exploit farmers and to hinder free research via patent laws.

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  8. 8. Bill_Crofut 3:49 pm 11/5/2012

    Re: The National Center for Science Education states that “The only difference between natural selection and artificial selection is whether the difference in reproductive success is driven by naturally occurring processes, or whether the selection is imposed by humans.”

    Botanist Prof. Frank B. Salisbury would seem to have challenged that notion:

    “I have my doubts about one point in the concept [of] Neodarwinism…The problem is the origin of variability…The modern theory emphasizes the importance of genetic recombinations but ultimately rests upon mutations as the source of the variability acted upon by natural selection. This is where I run into problems…Could random changes in the nucleotide sequences of DNA (mutations) provide…(new) genes and ultimately the enzymes? At the moment I doubt it.”

    [1971. Doubts About the Modern Synthetic Theory of Evolution. THE AMERICAN BIOLOGY TEACHER, September, p. 335]

    What has changed in the intervening four decades?

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  9. 9. Bird/tree/dinosaur/etc. geek 4:31 pm 11/5/2012

    What has changed, Bill, is that willfully ignorant trolls and quote miners like you have showed up. Please leave now, before I call David Marjanovich to dismantle your online personality.

    Link to this
  10. 10. rRo12 7:23 pm 11/5/2012

    Great post. Reflective :) Thanks!

    Link to this
  11. 11. Shmick 2:48 am 11/6/2012

    Excellent article, always illuminating to examine out assumptions. The “natural” versus “artificial” is largely a distinction without a difference.

    Bops, put down the joint.

    Link to this
  12. 12. Bill_Crofut 9:30 am 11/6/2012

    Bird/tree/dinosaur/etc. geek,

    If Dr. Marjanovich will provide evidence from the scientific literature to refute the challenge posed by Prof. Salisbury, it’ll be a distinct improvement over that which has been offered thus far.

    Link to this
  13. 13. Tim303 10:37 am 11/6/2012

    Fascinating. We are talking about the right of an algorithm to execute–with wide implications for nonhuman (and indeed non-sentient) rights. I just posted on it: http://goo.gl/FHkWy

    Tim Morton

    Link to this
  14. 14. Charles Hollahan 11:19 am 11/6/2012

    For an example of animals which are probably not influenced by humans try the Bristlemouths, genus Gonostoma. One of the most common vertebrates on the planet is the fish Cyclothone sp. Certainly we have changed their input of food in some ways but they are far enough removed that the effects aren’t linked to humans directly as much as other vertebrates plus we’ve hardly changed their habitat.

    The idea of reserves for animals to evolve is just another method to create a buffer. I don’t have any disagreements with that. Humans tend to reduce diversity and increase species like coyotes and other species which tolerate humans and their cities. The midwaters don’t get that much influence. You could argue that we fished-out midwater animals like orange roughy and toothfish but not much in the open seas, but mostly near seamounts. I’m sure we’ve altered those habitats since we’ve fished-out those keystone predators near such places.

    Mutation is now considered to be something of a constant; the rate of mutation can be predicted and measured. The molecular clock is something that is still controversial but I think it has a lot meaning toward understanding evolution. Providing habitat for populations will show evolution with or without humans and it’s no longer thought to take thousands of years before changes can be seen.

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  15. 15. Bird/tree/dinosaur/etc. geek 12:14 pm 11/6/2012

    Would someone please delete Bill_Crofut? His quote mining and baseless fringe views are starting to get extremely annoying.

    Billy boy, if you want to troll, go try trolling on Tet Zoo again, and this time actually read what Marjanovich writes (and, for that matter, his citations). I warn you, though, Darren Naish does not like repeat trolling offenders (just ask Peter Mihalda and John Jackson).

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  16. 16. Bill_Crofut 10:52 am 11/7/2012

    Bird/tree/dinosaur/etc. geek,

    Why don’t you simply ask Ms. Martin to block my comments?

    We already know Mr. Naish has blocked my comments on Tet Zoo. Having already traded comments with Dr. Marjanovich, allow me to offer an alternative suggestion. Why don’t you refute the quotes in my comments with material taken from the scientific journals as mine were? As an alternative/alternative suggestion, pick any comment/citation by Dr. Marjanovich that you believe makes your case and we can debate it here (until my banishment from this web page).

    Link to this
  17. 17. Bird/tree/dinosaur/etc. geek 12:36 pm 11/7/2012

    Bill, you are a quote miner of the worst sort. You are also a shameless liar. Please leave now.

    Mrs. Martin, I refer you to this thread to show that Mr. Crofut is a pathetic quote miner:
    http://www.scientificamerican.com/article.cfm?id=penguins-in-all-their-weird-glory

    Link to this
  18. 18. Bill_Crofut 10:38 am 11/8/2012

    Bird/tree/dinosaur/etc. geek,

    Re: “You are also a shameless liar.”

    Of course, you’re prepared to follow-up the accusation with evidence, just as a change of pace.

    Link to this
  19. 19. Bird/tree/dinosaur/etc. geek 7:19 am 11/9/2012

    I provided a citation, Billy boy. Also, you lie so blatantly that providing a citation is actually an insult to the collective intellects of everyone else on this thread.

    Apologies for treating everyone else on this thread as if they were blind to the Crofut.

    Link to this
  20. 20. Bill_Crofut 10:35 am 11/9/2012

    Everyone on this thread,

    Please accept my apology for any insult (unintentional though it was) to your collective intellect.

    Link to this
  21. 21. naishd 11:44 am 11/9/2012

    Mr Crofut is not ‘blocked’ from Tet Zoo, not yet anyway.

    Darren Naish

    Link to this
  22. 22. Bird/tree/dinosaur/etc. geek 1:07 pm 11/9/2012

    @ Dr. Naish:
    1. You are my hero (long story).
    2. Your flightless bats article was the best thing I have ever read on Tet Zoo. BTW, the Greater Short-tailed bat (*Mystacina robusta*) was primarily a terrestrial predator and was mostly flightless. It was about the closest real organism to a Night Stalker or FP.
    3. Well, deleting all of his comments is about the same as blocking him. For doing so, I thank you, as you have continued to set the bar for science blogs. Tet Zoo is, in my opinion, even better than Pharyngula.

    Link to this
  23. 23. Jerzy v. 3.0. 12:28 pm 11/10/2012

    Simple as rock.

    Everybody who believes in right of organisms to evolve should sign a legally binding document not to interfere when bacteria or viruses invade his/her body.

    The problem is over. Don’t force others to do what you wouldn’t do yourself.

    Link to this
  24. 24. Jerzy v. 3.0. 12:37 pm 11/10/2012

    I naturally believe in conservation of both species and ecosystems. But changing scientifically and economically sound reasons of conservation into talk about right-to-evolve is not in interest of conservation.

    Link to this
  25. 25. geodude 12:59 pm 11/27/2012

    “protecting large mainly untouched areas where ecosystem processes, including evolution, can continue unhindered by human[s], including development or mass tourism.”
    Not to rain on anyone’s parade but where exactly are these untouched by human hands/pristine “wildernesses” being defined here? Certainly not in the Americas. Europe,Australia, India, China, . . .? Don’t think so. Humans have been burning and otherwise manipulating these regions for many tens of millenia. Perhaps the Antarctic and parts of certain other deserts. Maybe portions of the roof of the world. These regions do not strike me as the source of the unsullied genetic cornucopia people appear to want to preserve. Maybe the oceans . . . are untouched? Don’t think so.
    Humankind has been deliberately controlling the ecosphere on a global scale for a long, long time.
    Try another argument.

    Link to this

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