So You Think You Understand Evolution?

So You Think You Understand Evolution? April 11, 2018

If you think evolution is simple, you’re probably thinking of adaptationism. And that’s the Tinker Toy version of evolution.

Is Adaptationism Pseudoscience?

If you’re still describing evolution in terms of a struggle for existence where every trait of living organisms has been selected according to its ability to confer reproductive success, then you’ve fallen for adaptationism. This is the tendency to emphasize selection over all other mechanisms of evolution, and indeed, to define evolution as adaptation itself rather than phylogenetic change (modification of the physical aspects of organisms). Darwin himself said that natural selection was not the only mechanism of descent with modification; he never himself used the term evolution because of the way it implied progress toward a goal.

Darwin has become an icon to us, a scientist who made the world see nature a whole new way. So why is it that so many people who admire him have a very poor grasp of evolution? Darwin’s theory was one that characterized nature as chaos, creativity, and destruction. However, our pop-science poobahs have made a great living redefining evolution as a mechanical process, an “algorithm,” another machine fantasy for our tech-obsessed culture.

Natural Selection: The Explanation That Needs Explaining

The genetic aspect of species change has been extensively studied and is now very well understood. We now realize that non-selective mechanisms like genetic drift are extremely important contributors to evolutionary change. The field of evo-devo (the study of embryonic development) has made it clear that the staggeringly complex way genes interact and are expressed during gestation is crucial to the way the organism’s phenotype develops.

Natural selection, however, is really no better understood than in Darwin’s day. The novelty of Darwin’s theory was the way he made natural selection, until then understood as a merely conservative force, a mechanism for evolutionary change. The effect that the environment has on species is to increase their fitness by eliminating all the members of a population except the favored variants. Even though Darwin was said to have proposed a “causal mechanism” for changes in phenotype, natural selection has never been anything more than a conceptual placeholder that points the way to analyses of what, specifically, conferred fitness on one variant over another.

The problems with these post-hoc analyses are many. Looking down the wrong end of the telescope at natural history is bound to give us a distorted view of it, and selective scenarios tend to be little more than modern folklore that says more about our preferences than about nature’s.

The End of Adaptationism

Stephen Jay Gould and Richard Lewontin published a paper in 1979 titled The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme that took this adaptationist thinking to task as the facile oversimplification that it is. One metaphor they used was the spandrel, a feature of a cathedral that was only the decorative workaround necessary for the way a dome fit onto supporting columns, not the main artistic element of the structure. In looking at traits in a modern organism, they said, we need to acknowledge that some are adaptations and some are coincidental by-products of the selective process.

The other metaphor was Dr. Pangloss, the nutty philosopher from Voltaire’s Candide whose explanations of everything from human clothing to the horrifying destruction wreaked by the Lisbon earthquake was predicated on the self-validating assumption that things were the way they were because they couldn’t be otherwise. In the same way, selectionists speculate about selective pressures that gave rise to a certain trait that they only assume is an adaptation because otherwise the organism wouldn’t have needed the trait to respond to the selective pressure. Dizzy yet?

Coming up with plausible scenarios for how traits evolved is as easy as shooting fish in a barrel. As Gould and Lewontin wrote:

We fault the adaptationist programme for its failure to distinguish current utility from reasons for origin (male tyrannosaurs may have used their diminutive front legs to titillate female partners, but this will not explain why they got so small); for its unwillingness to consider alternatives to adaptive stories; for its reliance upon plausibility alone as a criterion for accepting speculative tales; and for its failure to consider adequately such competing themes as random fixation of alleles, production of nonadaptive structures by developmental correlation with selected features (allometry, pleiotropy, material compensation, mechanically forced correlation), the separability of adaptation and selection, multiple adaptive peaks, and current utility as an epiphenomenon of nonadaptive structures. We support Darwin’s own pluralistic approach to identifying the agents of evolutionary change.

The point is that adaptationist scenarios don’t explain anything except our tolerance for easy answers. The notion that fish are “uniquely adapted to their environment” because they live in water and not in trees doesn’t tell us anything about how they got there. Explaining that rhinos have horns because all the rhinos who didn’t died out doesn’t really explain why rhinos have horns. And peddlers of selective stories assume that it’s easy to distinguish selected-for traits from mere free-riders, without any justification for this assumption. If we’re determined to reject claims that aren’t backed up with evidence, then let’s admit that the vast majority of these just-so stories have to be discarded.

Selecting the Fittest Stories for the Social Order

Furthermore, there’s no use pretending that these selectionist stories are free of cultural prejudices. Elaine Morgan described in The Descent of Woman how our understanding of early human evolution is based more on bias than evidence. Our culture is infatuated with the hunter-warrior mythology Morgan calls “The Tarzan Myth,” so all the traits we assume arose in ancient male humans, such as erect posture and manual dexterity, derive from the need to hunt and fight. Meanwhile, the traits we assume arose in ancient female humans, like breast size and hairless body, we attribute solely to their value for the delectation of the male. This sexist Panglossianism is no more scientific than anything Ken Ham or his ilk could come up with, but prominent anthropologists push it with a straight face.

Nowadays, evolutionary psychology has popular appeal because it purports to explain complex cultural phenomena as the result of selective pressures in our evolutionary past. Thus, things like the gender wage gap and the disproportionate incarceration rates for African-Americans in the USA get explained in terms of the differential reproductive success of our ancestors on the savanna. This is nothing more than using the trappings of science to explain away social inequities. If this doesn’t demonstrate the way selectionist stories tell us exactly what we want to hear, nothing will.

Friends Don’t Let Friends Science Wrong

Having a better understanding of the theory of evolution by natural selection than a creationist is about as praiseworthy as being able to tie your shoes all by yourself. If we’re going to point at creationists and laugh (and we’re going to, because it’s fun), we should make sure our understanding of evolution isn’t just as selective and ideologically-motivated as theirs.

The problem is that we see what we want to see in Darwin’s theory. The idea of natural selection, the merciless pruning of the population by the indifferent environment, resonates in the collective imagination of a culture that’s still in the thrall of neoliberalism. The emphasis on competition panders to our love of warfare and our macho illusions about nature; the idea of selection tells us exactly what we want to hear about progress and superiority. We’ve come to think of the natural world, like our civilization, as a meritocracy where those who prevail are somehow more deserving of success.

A Word To the Wise Guys

I welcome discussion about scientific controversies concerning things like the mechanisms, genealogical pathways and rates of evolution. What I don’t want is debates over creationism. Species evolve, let’s move on. And if anyone feels like calling me a creationist, I’ll assume you’re not equipped for civil dialogue and your posts will go the way of the passenger pigeon.

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  • Maine_Skeptic

    I don’t understand what point you’re trying to make or what audience you’re trying to reach.

    For example, you say “This is the tendency to emphasize selection over all other mechanisms of evolution…”

    What do you mean by “other mechanisms of evolution?”

    You say “The notion that fish are “uniquely adapted
    to their environment” because they live in water and not in trees
    doesn’t tell us anything about how they got there.”

    Agreed, but natural selection does explain how some plants and animals became land creatures and others stayed in (or returned to) the sea. Are you suggesting it doesn’t? Or are you suggesting that a lot of skeptics believe that there’s a part of the evolutionary process that *anticipates* the next needed mutation? Who are you trying to convince, and what are you trying to convince them is the truth?

  • I don’t understand what point you’re trying to make or what audience you’re trying to reach.

    I’m addressing this to people who appreciate that evolution still has a lot of expert debate about many of its aspects. People who just use it as weaponized knowledge for rounds of slap-the-fundie probably won’t find anything particularly interesting here.

    What do you mean by “other mechanisms of evolution?”

    The ones I mentioned, like genetic drift. Biologists (Darwin included) have always realized there are a lot of mechanisms for evolution, and there’s controversy about the traditional emphasis on natural selection.

    natural selection does explain how some plants and animals became land creatures and others stayed in (or returned to) the sea.

    I’m not disputing that land animals have ancestors that were aquatic species, and vice versa. (one of my favorite pop science books is At The Water’s Edge by Carl Zimmer, which deals with just this subject) But there was a lot of phenotypic change that had to take place for these kinds of transitions, and there are a lot of biologists who doubt that the same mechanisms that turn moths black are adequate for such transitions. I’m not saying there’s anything magic to it, just that coming up with selective explanations for it is bound to have a lot of fact-free speculation involved.

    I’ve quoted H.L. Mencken many times: “For every complex phenomenon, there’s an explanation that’s simple, elegant, and wrong.” Natural selection as a magic algorithm that does it all is just one of those explanations.

  • aвѕolυт clancy

    I’d partially blame the phrase “survival of the fittest” for misunderstanding of Darwin’s ideas. It’s an oversimplification that creates a picture of Hunger Games-type competition as the only deciding factor in who survives and gets to make the next generation. In reality cooperation and selflessness are also significant determinants of how and whether a species survives and develops.

    In the film Expelled: No Intelligence Allowed Ben Stein, trying to whip up some fervor about science’s conspiracy to keep God out of education, cherrypicked Darwin to comment [I’m paraphrasing here] that the weak are eliminated by savages but allowed to perpetuate by the civilized, and how detrimental this is to humankind. It was only one misrepresentation of Darwin in that film – what he actually wrote was:

    It is surprising how soon a want of care, or care wrongly directed, leads to the degeneration of a domestic race… if we were intentionally to neglect the weak and helpless, it could only be for a contingent benefit, with an overwhelming present evil. (The Descent of Man)

    Anyway, now we see “survival of the fittest” used to justify brutal competition even in situations as far removed from Darwin’s work as the corporate world.

  • stphneye1971

    Your article is very well put.

    For me, adaptionism is just another part of scientism, as opposed to, say, being scientific. In my opinion, scientism stems from a preoccupation with disproving intelligent design using science. That is understandable given the circumstances and I feel fortunate enough to have been taught evolution throughout my schooling including one year in a Catholic school.

    There has to be a simple, consistent message but I don’t think scientism has got it. That is because scientism is merely a response to theism, and as such, inadvertently steers us into circular logic, fallacious argumentation, and other “dizzying,” fun mind-games. The scientist role-plays a theologian.

    It is not necessary for a militant atheist to tell me that genes do not care about how we feel about their speculations and their supposedly “scientific” conclusions about race and gender. But that tends to be one of a few preferred, almost canned responses. It is an educational tool, no more important to science than G-d is. They’re probably learning themselves.

    It would be just as easy to say these bots can’t be civil because they are deliberately putting people off scientific reasoning. Or they have other motivations such as using arguments off one forum in order to use them on another.

    Oh well, I guess the “simplest explanation is best” for some, even though they often aren’t the simplest explanations – they’re just the easiest – copied off the YouTube sound bites of Pinker, Krauss and Dawkins, et al. Easy.

    The simplest explanations also beg us to form more questions and these bots certainly have an “unwillingness to consider [plausible] alternatives to adaptive stories.” Watch out when you do question them and they scream “Ockham’s razor! or “you don’t understand!”

    It is interesting how we use information.

    I’m yet to read the Dialogue but thanks for that.

  • I should ban you for reminding me of that slipshod Ben Stein movie! I’ve never seen anything so witless in my life.

    Yeah, “survival of the fittest” is not only an oversimplification, it’s wrong. The point is that natural history is a dizzyingly chaotic process, and we’re desperate to impose some sort of algorithmic order on it. What Darwin did was make us acknowledge the devastating costs for even a slight increase in local fitness, as Nature’s trial-and-error process wipes out variants for what we consider disconcertingly arbitrary reasons. Natural selection and adaptation undoubtedly accounts for the survival of many organisms/species/traits/genes, but there’s no way they exhaust the possible mechanisms of phenotypic change.

  • I totally agree. In fact, I think the natural part of natural selection has become a debunker dog-whistle, as if the only conceivable alternative to natural selection is some sort of magical or supernatural force. It’s hardly a surprise that the first comment here started out, “I don’t understand what point you’re trying to make or what audience you’re trying to reach.”

    It’s too bad that a subject as rich and fascinating as natural history gets turned into ammo for online factoid wars. My only hope is that people will graduate from debunkery and develop a more nuanced understanding of science and knowledge.

  • stphneye1971

    What strikes me about Origin of Species is that Darwin took such great care with his writing to address his most doubtful contemporaries.

    Dawkins’ Climbing Mount Improbable was a keystone moment in my thought. I don’t mean to criticize him too much because, as I was meaning to say before, I am in a privileged position compared with some of the people who find hope in his activism. In the US, the UK and Africa for example. I recently put a cheeky comment on his tweet to realize there is a lot of pain that I’m not aware of.

    But we must write without needing to excuse ourselves for personifying Nature when we use a pronoun, as Darwin had needed to do. We must write giving our own definitions of what an environment actually is in a feedback loop. Does the environment include our bodies? Does the brain include the entire nervous system? Do we need the construct of the mind and the ego to describe and predict our next position, as we slither across the substrate of life which spans enormous geological periods? Are our flagellum the internet?!

    For want of brevity I didn’t mention before how I felt slightly relieved that you even mentioned feedback.

    A few years ago I enjoyed some excellent debates on the Richard Dawkins website. At that time I was very much into cybernetics and behaviorism, which, although easily criticized make a deal out of the organism effecting the environment. In behaviorism, it is a major statistical confound. But I was confounded by the crickets chirping when I mentioned feedback mechanisms.

  • stphneye1971

    The sick organisation confuses the struggle for existence with survival of the fittest. Or Chapter 3 over chapter 4 of the Origin of Species.

    I always want to refer people to original texts but it has become laborious for me when it comes to Darwin, for which I feel some shame. I hope we can transcend paraphrases and exact quotes.

    And yes, what are you doing watching that rubbish!

  • aвѕolυт clancy

    And yes, what are you doing watching that rubbish!

    I know…double facepalm. I try to stay informed about the thinking of folks who don’t share my beliefs but sometimes it’s a lot more painful than others!

  • stphneye1971

    Know thy enemy bud.

    Hard.

  • Maine_Skeptic

    “In reality cooperation and selflessness are also significant determinants of how and whether a species survives and develops…”

    I think cooperation and selfishness have still been a result of “survival of the fittest.” Where people– usually creationists or alt-right assholes– misunderstand evolution is that it’s not “every animal for itself.” Cooperation is an evolved advantage, too, and not just for humanity. Pack animals, herd animals, and colony insects have all evolved methods for working together.

  • Maine_Skeptic

    Thanks for that explanation. I don’t run across many people who use evolutionary as a bludgeon against fundamentalists, because most people either don’t believe evolution is real or couldn’t explain natural selection if they do accept the theory.

  • I don’t run across many people who use evolutionary as a bludgeon against fundamentalists

    You seriously want me to believe you’ve rarely run across that? Because it seems pretty common to me.

  • Mr. A

    You have to keep in mind though that the reason people have a simplified view of evolution is because the science itself is more complicated than adaptationism, as seen by your examples above. The laypeople do not have time nor energy in thier daily lives to understand the implications of a web of life versus the more simple tree of life, for instance. Most of them just want to live out thier lives without having to become experts on every topic. To me at least, these people are forgiven for this reason.

    Now if an actual scientist presented me with an adaptationist viewpoint, then we’d have a problem. Luckily I haven’t met anyone like that in my (short) life.

  • Lawrence Lemer

    The brief intro stopped short. I expected a more thorough examination of this very important topic. So far, so good. I agree 100%. People need to be educated. Keep going!

  • Maine_Skeptic

    “You seriously want me to believe you’ve rarely run across that?”

    Not only should you believe it, but you may want to ask if your own experience is common at all. Forty percent of the US population believes some form of creationism. Of the 60% who accept evolution as true, I’d bet that less than half could explain how it works with any accuracy. A much smaller percentage than that is inclined to talk about evolution with fundamentalists. Some just aren’t argumentative. Others have good reason to fear hurting their careers by doing so.

    I’ve lived in several different parts of the country, and I’ve associated with people from different walks of life. I’ve never found myself surrounded by people who could discuss the finer points of evolution.

  • Bob Jase

    There is that one factor in natural selection that no one likes to talk about.

    https://youtu.be/D7k43VGZHpE

  • You have to keep in mind though that the reason people have a simplified view of evolution is because the science itself is more complicated than adaptationism

    And it could also be, as I said, that conflating adaptation and evolution makes it easier to push prejudiced just-so stories that validate the social order. As Hawking used to say, the opposite of knowledge isn’t ignorance, it’s the illusion of knowledge.

  • Mr. A

    Oh yes, that could very well be the case. People will do anything to justify thier beliefs of superiority after all.

  • How about contributing something to the discussion before going right to the corny video, huh?

  • Bob Jase

    Can’t handle subtlety, eh?

    No one likes to talk about the fact that blind luck is a feature of natural selection – did you think that all the life forms wiped out in the great extintion events had time to adjust or mutate or relocate?

    That was my point, too bad you couldn’t see it.

  • Contractions of Fate

    “Survival of the fittest” in a Darwinian context refers to genetic, biological and reproductive “fitness”, where “fitness” is a biological concept to do with adaptability, reproducibility and heritability within an environment. It has absolutely nothing whatever to do with “Only The Strong Survive” or any of that other scientifically illiterate bollocks. The “fittest” could be a parasite that does not kill it’s host, the strongest lion on the savanna the fastest gazelle on the savanna, the grass with a higher tolerance for copper, a fruit that tastes sweet and so is eaten and it’s seeds distributed more widely, a cactus that can store more water and has sharper spines, a stickleback with no spines, a zebra fish with transparent blood and an anti-freeze and so on.

    So, once again, it’s not the biological terminology which is to blame, but the under-educated, pig-poo stupid morons who don’t understand what the hell they are talking about; even when the concept is grossly over-simplified for them.

    >:8o

  • Wile F. Coyote

    And it can’t be pointed out too often that it was not Darwin who coined “survival of the fittest”:

    http://newlearningonline.com/new-learning/chapter-4/herbert-spencer-on-the-survival-of-the-fittest

    Herbert Spencer on the Survival of the Fittest

    Herbert Spencer (1820–1903) was an English philosopher who initiated a philosophy called ‘Social Darwinism’. He coined the term ‘survival of the fittest’ seven years before Darwin’s publication of his theory of natural history, The Origin of the Species in 1859. Spencer became an enthusiastic supporter of Darwin’s theory of evolution, believing it could also be applied equally well to human societies.

  • See? Was that so hard?

    I fully admit that natural history is a contingent process, and most times being in the right place at the right time is what allows your genes to survive. But technically that type of arbitrary event is not natural selection, since a selective process is one where variants survive because of heritable traits or fortuitous adaptations.

  • Read every word with great interest but I’m feeling short changed here. As a teenager 50 years ago, I could see that adaptation did not answer (for me anyway) many of the changes that occur in species .Instead of pursuing those answers I mainly concentrated on getting laid but now that you have put my doubts into perspective, how about providing some answers, in the small chunks my limited intellect can absorb. I know ‘it’s complicated’ but try.

  • aвѕolυт clancy

    Sorry for off-topic – I’ll hide this in the midst of your comments here – but idk if you’re familiar with this site, aeon. I’ve been following it lately and there’s been some good writing. This piece is too far over my head in terms of philosophy, but some of the themes here (literature, reflection, ethics, technology – and of course the philosophy) made me think it might be of interest to you.

    Edit – my link isn’t showing up…let’s try this again: aeon.co/essays/take-your-time-the-seven-pillars-of-a-slow-thought-manifesto
    Okay, not sure what I’m doing wrong, sorry. If that link doesn’t work, try Googling “aeon seven pillars slow thought manifesto”

  • C_Alan_Nault

    The fact is even if the scientific theory of evolution was disproved tomorrow, it would not prove the claim/belief a deity of some kind was the cause of anything.

  • Maine_Skeptic

    “There is that one factor in natural selection that no one likes to talk about.”

    That’s why 40% of the US refuses to accept the evidence for evolution. They can’t stand the idea that so much of life is random.

  • Ann

    When new traits arise by random mutation, some will be harmful and some neutral. Others will be exploited by the phenotype for new interactions with the environment.
    When a randomly-useful adaptation causes a change in the proportion of alleles, then “evolution” has occurred (but not, of course, speciation.)
    It doesn’t have to be more complicated than this.
    The typical error is to reason backwards, creating Just-So stories to account for observed phenomena, rather than beginning with a random event that could have taken, say, rhino ancestors in any direction, not necessarily horns.

  • Schreiber

    I looked to this article to correct what might be my simplistic misunderstandings of evolution. I’m afraid it wasn’t very helpful. The condemnation of popular evolutionary theory came through loud and clear, but exactly the various ways in which it is wrong, and particularly what ought to replace it as the correct understanding was wrapped in a cloud of jargon. Those with a good background in biology might benefit, but perhaps not those of us educated in other fields.

  • Bob Jase

    Well of course not, after all, their Dog has a plan which cannot be changed because Dog controls the universe and must be obeyed.

    Unless a believer can’t find a convenient parking place in which case Dog may be petitioned to change the eternal plan to save said believer a few steps.

  • Otto

    Additionally from what I see it is the fundamentalist that brings up evolution and tries to use it to show how absurd atheism is…not the other way around, as is being implied here.

  • Who said anything about a deity here?

  • Kevin Alexander

    Yes. I’m not so much bothered by creationists as by eugenicists who use a bastardized version of evolution to justify their illusions of supremacy. Even if you know nothing more than the simplistic adaptationist version of evolution the eugenicist program still fails. Evolution has two essential elements, variation and selection. By supposing that you can beat nature by doing the selecting all you end up doing is carving away the source of the variation so the future has nothing to adapt with. For instance, dogs are selected from wolf stock but are in no way superior to wolves. It took four billion years for nature to add to the genome to create a wolf. You don’t get dogs by adding more to that genome, there’s no way of doing that, you get them by subtracting. Or, as I like to say, if you could create a superior human with careful breeding, you could explain Prince Charles.

  • Phil

    It always infuriates me when this is missed by pretty much all media when explaining evolution. It usually starts with ‘the reason for’. Such has giraffes have evolved long necks to eat the leaves off tall trees. No they didn’t. The longer necks just didn’t kill them off. Being able to eat leaves off tall trees is a subsequent advantage. Humans have mucked up evolution by curing themselves of things that would kill us. So what would have killed you off before the chance to breed, survives. Shortsightedness doesn’t prevent us from breeding anymore and we certainly didn’t evolve shortsightedness to see computer screens better. Random mutations, as long as they don’t prevent you from breeding will survive. If the mutation then enables you to have some advantage then it may help to survive better. That is how I view it anyway.

  • Paul LentzJr

    An excellent treatment of the subject. I appreciate the reference to Gould and the link to his paper. I’ve read all of Gould’s books and was pleased to see he is still cited in legitimate papers. This paper barely scratches the surface, but inspired me to re-read some of Gould’s books. Thank you for the inspiration.

  • I appreciate the feedback. I was just trying to point out that “natural selection” is still more of a conceptual placeholder than a meaningful causal phenomenon. And the reason no one takes exception to appeals to speculative selective scenarios is that ideas like competition and selection satisfy our need to see nature and culture as vaguely meritocratic.

  • Gould is absolutely one of the finest science writers who ever lived. The thing I appreciate about his work is that he was always exploring the process of scientific inquiry at the same time as he explored the natural phenomena that were the subjects of inquiry. The cultural and historical details of how our knowledge developed were just as important to him as the knowledge itself.

  • I like Aeon! I’ve discussed their articles in posts on the Anti-Science channel. Thanks for recommending the essay.

  • Ann

    You are so right!

    Book publishers send sales people to college campuses, where they leave sample copies of their wares, hoping that one or another of the professors will adopt one of their textbooks for their classes. We put the rejected texts in a small library next to the science department office for the benefit of students who can’t afford new officially-assigned books.

    The major reason I insist we reject a book is exactly the kind of teleological reasoning that you have objected to.
    I flipped one book open at random and saw this caption under an image of a desert cactus:
    “The cactus has evolved long roots to reach water that is deep below the surface.”
    WRO-ong! Next text please.

    However, I disagree with you that overriding with medical interventions those impediments to reproduction that mattered in the past has mucked up evolution.

    That interference just isn’t important enough to make a dime’s worth of difference.
    Even if it were a significant input into the gene pool so that now we are breeding children who must rely on technology to survive (or anyway, to reproduce) — so what? We actually have the technology, just like we have the food to nourish creatures like us whose evolution caused us to be unable to perform individual photosynthesis. We rely on one another to supply our incapacitated selves with food and respirators and such like. The population level suggests that it doesn’t seem to have disadvantaged our species any.

  • Ann

    Shem, I was never able to rightly apprehend the difference between “adaptation” and “evolution.”
    Do you have time to give me a brief explanation?

    It’s my understanding that you are not thinking of “adaptation” to mean such changes as “muscle size increases with exercise” or “the skin tans when exposed to the sun.”
    It’s also my understanding that you’re not referring to epigenetic changes.
    I have the idea (Correct me if I have this wrong!) that “adaptation” in the sense you are using it refers to a genetic change that is passed on to the offspring.

    But I have always thought that evolution was defined as “a change in the frequency of any specific allele,” and that the accumulation of these adaptations might even eventually lead to speciation.

  • Mojohand

    I’m more always amazed at the misrepresentation of evolution one encounters. I often see people describe it as if it were a linear graph trending ever upwards (y=x) toward, idk…perfection? Rarely is this a straw man but instead an uniformed/misinformed idea of what natural history entails. It is far more a fractal graph with myriad branches and rabbit holes.

    Perhaps, religious reasons aside, we humans have a desire for simplifying which I would argue is often a good thing. But making things simpler (or simpler to understand) doesn’t necessarily make things simple. Life and it’s enviromental interactions ain’t that easy which only adds to its appeal to me. The ‘simplest’ explanation is that of the great scientist Jeff Goldblum, “life finds a way”.

  • I’m no expert, but I believe the distinction is that evolution is phenotypic change, or as you defined it, “a change in the frequency of any specific allele,” while adaptation means a heritable trait or behavior that increases the organism’s chances of reproductive success. The way adaptationists conceptualize evolution is that it’s strictly driven by adaptations; the variants favored by natural selection are the ones whose genes are better represented in the next generation.

  • One of the problems is that Darwin himself often conceptualized the process as one of improvement: “And as natural selection works solely by and for the good of each being, all corporeal and mental endowments will tend to progress towards perfection,” is what he wrote in the Origin of Species.

    I’m not saying there’s never a reason to simplify, or even to oversimplify. But we need to acknowledge when we’re doing so, especially if we start to use the simplistic explanation to explain away social inequities or validate our biases.

  • marbon67

    Thanks to the easy and universal ability to post on the internet we are witnessing the survival of writings that otherwise would never reach wide audiences other than through graffiti scrawled on surfaces close to heavily travelled roads and streets.

  • Bob Jase

    Darwin was still a product of his time, I expect he may well have considered evolution as a ladder rather than a bush. Survival as a species, even as a new & different one, is an ‘improvement’ over going extinct though its a quibbling point of wordplay.

  • Your own post certainly proves your point.

  • C_Alan_Nault

    I just did, pay attention. I was stating a fact: even if the scientific theory of evolution was disproved tomorrow, it would not prove the claim/belief a deity of some kind was the cause of anything.

    Generally, when anyone tries to disprove the theory of evolution, it is because it conflicts with their religious beliefs.

  • Oh. Kay.

    No one here is religious, and no one is trying to disprove the theory of evolution. I’m just questioning whether the adaptationist approach to natural history is popular because of evidence, or because it panders to our thirst for easy answers. Is natural selection really so crucial to evolution, or is it just crucial to the way we explain away social inequities and power disparities in our chrome-plated meritocracy?

  • Ann

    Hi, Shem ~
    Thanks for your prompt and courteous reply.

    I know that you are sensitive about being labeled a Creationist, and I don’t blame you one bit. Anyone would be ashamed of that.

    But perhaps you didn’t fully realize that it is Creationists who try to dismiss undeniable instances of evolution by claiming that they are only “adaptations.”

    It almost seems like your distinction between evolution and adaptation is a little bit incoherent — and wrong when it is understandable.

  • The one who appears to be overlooking things here is you, Ann, since you seem to think I’m saying the exact opposite of what I’m truly saying. I’m not denying evolution in the least: molecules-to-modern-species, unguided evolution is a fact, full stop. What I’m denying is that the cumulative effect of what we call adaptations is what constitutes this change, or that adaptations themselves are anything more meaningful than post-hoc rationalizations for the survival of certain organisms, species, body plans, or genes.

  • No argument here. I’m just saying you can hardly dismiss the evolution-as-improvement trope as a straw man when Darwin himself used such rhetoric.

  • Ann

    You refer to the “effect of what “we” (sic) (meaning “you”) call adaptations.”
    You say that the cumulative effect of these “adaptations” does not constitute evolution.

    Shem, each one of those “adaptations” IS evolution.
    That’s the DEFINITION of evolution.
    When the frequency of an allele changes in the genome, then the species has evolved by definition.
    https://www.khanacademy.org/science/biology/her/heredity-and-genetics/a/hardy-weinberg-mechanisms-of-evolution

    And it is the accumulation of these “adaptations” that causes speciation.

  • From the link you posted:

    All evolution means is that a population is changing in its genetic makeup over generations. And the changes may be subtle—for instance, in a wolf population, there might be a shift in the frequency of a gene variant for black rather than gray fur. Sometimes, this type of change is due to natural selection. Other times, it comes from migration of new organisms into the population, or from random events—the evolutionary “luck of the draw.”

    Evolution isn’t always the result of natural selection acting on adaptations.

  • Peter Hannan

    OK up to a point, but this pushes the Gould – Lewontin critique of “adaptationism” without once mentioning all of the work done by Richard Dawkins, Daniel Dennett and others to criticise that critique. If someone sets themself up to “educate” us on evolution, they had better do justice to the real complexity of the field and the range of discussion.

  • adriancrutch

    …I watched a four part series on Amazon about disease…cancer,heart disease,stroke,etc…it had a lot of evolutionary concepts for human development and disease…while at the same time showing cancer in the bone marrow of a Diplodocus…I’d recommend watching the series if you have Amazon Fire…it didn’t leave me “puzzled”…

  • Phil

    Ah, I do take your point. I don’t have any qualification in this, but it did seem to be obvious if you thought about it. Pity so many people that matter don’t seem to think things through.

  • Ann

    If you mean that a new allele spreads throughout the gene pool, altering its frequency in the genome, thereby “changing [the genome’s] genetic makeup over generations” — which is the very definition of “evolution” — by various processes including (but not limited to) natural selection, then that is a true but commonplace piece of information.

    Even Khan Academy’s Bio 101 lesson lists factors in addition to natural selection that advantage one allele over another, such as:
    > Non-random mating
    > Limited population size
    > Genetic drift
    > New mutations

  • Ann

    “Fitness” doesn’t mean “physically fit” in the sense of being able to duke it out.
    It means “fittedness” — well-adapted to the niche the species inhabits.

    For example, a sea creature might be more fitted than its siblings because it better resembles a swaying frond of seaweed than they do.

  • Having read Darwin’s Dangerous Idea, I realize Dennett got all flustered over the “spandrels” concept. Dawkins devoted an entire chapter in Unweaving the Rainbow to a petty attack on Gould’s Burgess Shale essays (without ever quoting him directly), and still never misses an opportunity to run down Gould in public even after he’s been dead for over a decade. If they made any cogent responses to the Gould-Lewontin critique, I guess it’s up to you to “educate” on the matter.

  • If you mean that a new allele spreads throughout the gene pool, altering its frequency in the genome, thereby “changing [the genome’s] genetic makeup over generations” — which is the very definition of “evolution” — by various processes including (but not limited to) natural selection, then that is a true but commonplace piece of information.

    You think so? I find it much more commonplace for people to use the term “natural selection” interchangeably with “evolution.” If we truly agree that not all evolution is selective, then I truly have no idea what you’re still hectoring me about.

  • The problems with adaptationist thinking are easy to see in the matter of evolutionary medicine or EM. Michael Cournoyea at the University of Toronto describes the way an adaptationist approach to medicine has been of limited use to the discipline:

    Much of the emphasis in EM’s early research program was on reinterpreting unpleasant and seemingly useless physiological processes as adaptive functions of bodily systems. Fever, vomiting, diarrhea, coughing, nausea, pain, fatigue, morning sickness, anxiety, and even jealousy were reconceptualized as adaptive functions of the body that had evolved to protect individuals from a variety of dangers (Nesse and Williams 1994). Recent papers in EM use the same adaptationist assumptions about humanity’s evolutionary past to justify norms of health and well-being. Solutions to the modern world’s “dietary crisis,” for example, can be found in an evolutionary perspective on nutrition, which highlights the disparity between “Stone Age” diets (the ideal to which we evolved) and current eating habits (which are far from ideal) in terms of quantity, quality, and variety (Cordain et al. 2005; Turner et al. 2008). This perspective also explains why many have difficulty digesting cow’s milk, bread, or root vegetables (Lindeberg 2010). Since the human body has not evolved to eat the kinds of foods consumed in affluent nations today, modern lifestyles have little to no evolutionary precedent. Medical research examining the health benefits of pre-agricultural lifestyles (such as the “Paleo” diet) is increasingly carried under the banner of EM.

    Noel Boaz (2002), professor of anatomy and anthropology at the Ross University School of Medicine, refers to such disparities between our ancestral health and our current health as discordances of “adaptive normality,” arguing that such normality is our “evolutionary birthright” (p. 5). Boaz makes it clear that evolutionary thinking—and, it seems, only evolutionary thinking—allows us to understand “what our normal ranges of environment, anatomy, physiology, and behavior really are” (p. 2, emphasis added).

    So according to the adaptationists, the evolutionary heritage of traits or processes is the most important thing to understand about them, and the key to clinical practice. However, it turns out that even when EM isn’t completely speculative, it’s of very little relevance in practice:

    Such adaptationist reasoning is disconcerting, because it can be misguided and potentially dangerous when applied to ideals of health and well-being. The program is misguided in proposing that we should define ideals of health and human nature based on speculative claims about humanity’s evolutionary past; it is potentially dangerous in suggesting that the “natural and normal” are best just because they are “natural and normal.” In this circular argument, such naturalizations may then appear to offer powerful justifications for what we should do, despite the worry that our ancestral life-histories are difficult (if not impossible) to test empirically.

    If the ideal function of some physiological process is found “in nature,” then malfunction, disease, and illness are interpreted as physiological malfunctions rather than biological variability. In a sense, theory becomes immune from error, since a “biological system can fail to behave as a theory predicts without impugning the prediction: we can say that the system is malfunctioning” (Murphy 2008). To take a controversial example, homosexuality might be pathologized and medicalized as bodily malfunction rather than used to question adaptive ideals of heterosexuality. Normalization and naturalization begin to blur when normative views are subtly naturalized. These concerns are even more salient when adaptationist thinking is used to propose species-wide or racially specific standards of health, rather than considering the complexities of sociocultural dissimilarities or the uniqueness of an individual’s subjective health. EM necessarily precludes these approaches, because it naturalizes and defines health/disease in supposedly objective adaptationist terms. EM may even trade one fallacy of medical normalcy for another, rejecting ethnocentric ideals of health for one that is biocentric, based on speculative ancestral conditions. While these are dangerous normative directions for EM, they might be avoided by reconsidering EM’s strong adaptationist stance.

    Again, no one is disputing that humans are the products of evolutionary processes or that certain traits are adaptive. What’s being disputed is whether we should define well-being in terms of adaptive importance, or whether the evolutionary legacy of a biological function is more relevant to clinical practice than the sociocultural or personal context of the patient’s condition and treatment.

  • I’d say I understand evolution quite well, but that’s because I understand probability theory, genetics, thermodynamics, etc.

  • an0maly

    “Humans have mucked up evolution by curing themselves of things that would kill us.” implies that evolution has a direction or intent, that humans are interfering with the proper and correct functioning of evolution. This is exactly the misguided view that the OP is talking about. There is no intent, no direction; it just happens according to natural forces. The way humans behave is caused by their nature which was the product of evolution, so their actions are not “mucking up” some divine process, they are merely part of that process of nature. If humans cause themselves to go extinct, that extinction will be part of the process too. Not happy for us from our own perspective, but not a violation of some imagined cosmic plan.

  • Phil

    Well you obviously misread what I actually said!

  • I’m sort of wondering too what you meant by Humans have mucked up evolution by curing themselves of things that would kill us. You seemed to be doing pretty well by saying, for example, that giraffes didn’t evolve long necks for eating leaves off tall trees. But then you lost me.

  • Phil

    It was just an observation that due to technological advancements people can live and breed whereas some mutations would have put them at a disadvantage in the natural world and the trait die out. However as someone pointed out, evolution of the brain and opposable thumbs etc has led to the tech. So the technological advancements are very much a part of evolution.