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No longer a topic for science fiction, the power of artificial intelligence is already reshaping our lives in ways that were unimaginable just a couple decades ago. AI goes well beyond self-driving cars, Facebook ads, and robots that can run obstacle courses. Your email client can respond to messages for you; your preferred music provider will customize your playlist; and Google Translate is improving by learning from its millions of users, rather than waiting around to be programmed. In the US, courts are even using AI-trained algorithms to decide the most effective sentences and parole conditions for offenders. (A troubling development, to be sure.)

It can all sound very scary. Keep in mind, though, that almost all of this progress on artificial intelligence is on the performance of specialized tasks, data collection, or predictive algorithms. The type of AI that is particularly important now is often called “machine learning.” This branch of AI includes powerful computer programs dedicated to solve specific problems, but these algorithms not to grow on their own and consider other kinds of problems to tackle. In other words, there is not even an inkling of “general intelligence” in the machine learning tools that are being developed at a dizzying pace around the world. The robot that jumps the hurdles will not stop and think about what the hurdles are made of. The computer that drives the car will not stop and question the ethics of allowing a crowd-skipper into the exit only lane at the last minute.

But what happens when they do? The Southern Baptist Convention recently put out a lengthy policy statement about the Christian moral principles that are at play in the field of artificial intelligence. Since I am not an adherent of that religion, I would not have even noticed. However, Dr. S. Joshua Swamidass, a biomedical scientist and AI researcher, just published an op-ed in the Wall Street Journal urging the Southern Baptist Convention to slow down and first engage with the field of artificial intelligence before starting to develop theological and doctrinal claims about it. After all, the scientific field is still in its infancy, but once doctrinal claims are promulgated, they begin to harden and become entrenched in the culture of the denomination. That is what Dr. Swamidass is hoping to avoid.

In addition to being an accomplished physician-scientist, Dr. Swamidass is also an evangelical Christian so his is a friendly voice from within the community. He also knows what he’s talking about when it comes to AI. His work on how AI is revolutionizing drug discovery was recently discussed in the pages of The Scientist. I have also published work on machine learning and I heartily endorse Swamidass’s message. While careful oversight is vital, artificial intelligence holds enormous potential for the betterment of the human experience. Religious organizations speaking out against this technology may end up looking very short-sighted.

The point that Swamidass is making is that the Southern Baptist Convention, and indeed any organization preparing to take positions on artificial intelligence, would be well served by exploring the potential and the pitfalls of AI with the scientists that work on it before taking any hard stances. The fear and dread that AI often inspires is usually based on a comic book version of the reality. (literally!) So, too, are the theological challenges to the notion of human personhood. The time for religious statements may indeed come, but shouldn’t the  doctrinal proclamations be informed by the fullest scientific understanding possible?  As Swamidass points out, most of the signatories to the SBC proclamation are pastors and theologians. A couple are AI technologists, and none are scientists.

Swamidass and I approach the profound questions of human life from very different starting points, but when it comes to AI, we have ended up in the same place. Institutions, governments, and organizations, both religious and secular, should take the time to familiarize themselves with what AI research has the power to do. They should listen and learn from AI scientists themselves, rather than basing their conclusions on overhyped press and unfounded fears. This exciting new science holds the potential to advance some of the very values that the Southern Baptist Convention holds dear. We may find that AI is fertile common ground for the religious and the secular, as it has been for Swamidass and me.

-NHL

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What constitutes beauty?

Among cultures and through history, standards of beauty have changed considerably. At certain times, stoutness was a symbol of wealth and influence, and thus was considered attractive. At other times, robust health and hardy physical fitness were the gold-standard. Skin tone, facial hair (men), breast size (women), eye color, hair texture, color, and style…  these have all experienced wide swings in attractiveness at different moments in space-time. When it comes to physical attraction, cultural forces far outweigh biological ones, but there are a couple features that seem to cut through the cultural milieu and are seen as universally attractive. (Read/listen to research about how our brain computes attraction.) 

For example, across cultures and times, height is reliably rated as desirable in men. For women, a low waist-hip ratio is seen as attractive globally. Of course, these two features are each just one aspect within a full suite of qualities for a specific person and do not overpower everything else. However, there is indeed something special about them simply because they are so universal while most other “attractive features” are not. This is evidence for (but does not unequivocally “prove”) an ingrained biological basis for the attraction.

There is another feature that drives perceptions of attractiveness and does so almost equally among men and women: facial symmetry. Across many clever experimental designs, researchers have confirmed that we rate faces that are more symmetrical as more attractive than those with less symmetry. Like height in males and waist-hip ratio in females, symmetrical faces are more attractive to people across cultures and historical times. But where does this biological attraction to facial symmetry come from? First, we must consider how symmetry develops.

Like all vertebrates, humans have bilateral symmetry. For the most part, our right side develops as a mirror image of our left side. Beginning during embryonic development and continuing through growth and maturity, the same developmental genes should be activated in the same cells at the same time and with the same dosage. In the ideal situation, all of that unfolds identically in the left and right sides of our faces, leading to perfect symmetry between the two halves.

Of course, in the real world, the tiniest fluctuations in gene expression and cellular activity lead to small differences between the two halves of our face. Look closely at your face in the mirror (or a friend’s face). You can usually see that one eye is slightly larger than the other. The larger eye is also usually higher. The nostrils usually show asymmetry in their size and shape as well, and the height and size of the ears can be surprisingly asymmetric also. All of this micro-asymmetry adds up to a symmetry score for each human face and these symmetry scores strongly influence how attractively we rate faces. Using CGI, researchers can transform an image of a face that most people rate as highly attractive into one that rates much poorly simply by tweaking the symmetry.

photo source

But why do we find symmetrical faces more attractive? The dominant scientific explanation for the attractiveness of facial symmetry is sometimes called “Evolutionary Advantage Theory.” If the grand choreography of developmental gene expression is perfectly executed, the result is perfect symmetry. Therefore, anything less than perfect symmetry indicates some kind of dysfunction, however small. If, on one side of the face, a gene gets expressed too much or too little, in slightly the wrong place, or a bit early or late, the tissue will take shape in a slightly different pattern than on the other side. Most of these small fluctuations result in what is called micro-asymmetry, which we can’t detect with the naked eye (but may be subconsciously aware of).

However, larger differences in symmetry may indicate issues that have occurred (or are ongoing) with the growth and development of the individual. Some factors that are known to affect facial symmetry are infections, inflammation, allergic reactions, injuries, mutations, chronic stress, malnourishment, DNA damage, parasites, and genetic and metabolic disease. Each of these are potential handicaps to the success of the individual and possibly his or her offspring. While the resulting facial asymmetry is probably the least of the person’s worries, the rest of us respond negatively to it because it could indicate reduced fitness. Since mating strategies invariably involve the pursuit of the highest quality mate possible, facial asymmetry knocks someone down a few pegs in terms of their attractiveness. This is the currently dominant thinking about why humans strongly prefer symmetry in each other’s faces.

The preference toward symmetrical faces is not limited to sexual attraction and mate selection. Facial symmetry appears to influence how we pursue friends and allies as well. Of course we all want a “high quality” mate and co-parent of our children, but we also want friends that are high quality and, dare I say it, high status. It’s an awful thing about us, but everyone wants to be friends with the rich, powerful, and popular. This reality has become crystal clear in today’s society where people can be “famous for being famous,” having produced essentially nothing of value to anyone and possessing no identifiable skills, talents, or accomplishments and still somehow be known as an important “influencer.” I digress.

It’s not altogether surprising that we, as a species, would read so much into faces. We speak face-to-face and we spend a lot of time looking at each other’s faces even when we’re not in conversation. We also have an exceptional incredible diversity in our faces and this probably comes from the face-centric nature of our social interactions.

In sum, facial symmetry is universally associated with beauty and attractiveness in both sexes and in sexual and non-sexual contexts. The most well supported theory for this is that our species has evolved to recognize symmetry, if unconsciously, as a proxy for good genes and physical health. This gives us a tentative answer to the question: what’s in a face? 

-NHL

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I recently hosted Dr. Kaliris Salas-Ramirez, a scientist at the City College of New York, on my podcast, This World of Humans. The subject of our conversation was her work on taurine, an ingredient found in popular energy drinks, and its effects on the brain. There are tons of surprising twists and turns in this story and when it comes to the health risks and benefits of this quirky amino acid, the news is not all bad!

Dr. Salas-Ramirez studies taurine from a neurological and developmental point of view and she is driven to discover and understand the risks and benefits of taurine, whatever they may be. This is clearly an important area of study because billions of cans of energy drinks are being guzzled every year, a large portion by teenagers and young adults, whose brains are still developing. (In the US alone, energy drink sales topped $3 billion in 2018.)

Because energy drinks, such as Monster, Rockstar, Jolt, and, of course, Red Bull, are often consumed together with alcohol and sometimes combined with other recreational drugs as well, a great deal of the research is focused on addiction. There are conflicting reports on whether taurine and energy drinks potentiate addiction and, as Dr. Salas-Ramirez has found, there seem to be sex differences as well. But the effects of taurine go way beyond addiction, and so does Dr. Salas-Ramirez’s research.

Different energy drinks have different formulas, of course, but the key ingredients in most of them are caffeine, which is already familiar to everyone, and taurine, which usually isn’t. Taurine is often called an amino acid, but it isn’t one in the traditional sense, either structurally or functionally. It is not used by cells to make proteins, for example. Instead, taurine participates in a variety of processes throughout the body from osmoregulation in the kidney to the conjugation of bile acids in the liver.

Taurine is “essential” in the sense that it performs important functions, but it is not essential in the dietary sense because our bodies can make all the taurine that we need. We make it by converting from the precursor cysteine, which is one of the traditional amino acids and one that we can also make for ourselves. In other words, we don’t have a nutritional necessity for taurine, but it is found abundantly in all animal products. (Cats, however, have lost their ability to make taurine which is part of why they are “obligate carnivores.”)

Taurine is added to energy drinks because it has been widely reported, and confirmed by some studies, that large doses can give us a boost in energy, ability to focus, memory recall, and even athletic performance. It is not entirely clear how it does this, but its effects in the central nervous system seem to be the most likely explanation. Taurine potentiates calcium signaling, which is key to how muscles contract and how neurons communicate with each other, and this seems likely to play a role in taurine’s central nervous system effects. But there’s definitely more going on that we haven’t fully worked out.

In her laboratory, Dr. Salas-Ramirez explores the effects of taurine on the brains of rodents and has made surprising discoveries when it comes to addiction, memory, and other cognitive functions. The effects of taurine appear to be widely different effects based on age, sex, and, perhaps most importantly, interaction with other drugs. For example, for older women, taurine may actually provide a little boost in memory.  The theme of this fascinating episode is: It’s complicated. In our interview, almost every time I thought we had reached a solid conclusion, Dr. Salas-Ramirez would interject with a, “Well, yeah, but…”

Check out episode #10 of TWOH in which I sit down with Dr. Salas-Ramirez as she walks me through what we know about the effects of taurine on the brain. It’s not all bad news! Listen to the episode to find out why.

As always, don’t forget to subscribe and tell all your friends!

Podcast website: https://goo.gl/VnuzKh
SoundCloud: https://goo.gl/JjX2NS
iTunes: https://goo.gl/53KCf9
GooglePlay: https://goo.gl/s2afxK

-NHL

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I just published an entry for the soon-forthcoming Encyclopedia of Evolutionary Psychological Science (edited by husband-wife team of Todd and Viviana Weekes-Shackelford) entitled, Maladaptive By-Product Hypothesis. Here is an introduction to the encyclopedia series, which is very large and ambitious. And here is a link to the full entry itself, for those who can access it. (And for those who can’t, please email me and I will share it with you.)

Maladaptation is an interesting phenomenon. As I define it in this essay:

In evolutionary psychology, maladaptive theory holds that some human behaviors are the result of past selective forces that are no longer operative, usually because of changes in the physical and social environment, resulting in behaviors that are no longer beneficial for fitness.

This really isn’t such a stretch. Our psychology – that is, the way our brain makes sense of the world we live in, the way it computes all the inputs that bombard us, the way it executes programs as we make decisions, was slowly shaped over millions of years of time. This is why we have such strikingly similar motivations and emotions as other animals. (That similarity is the subject of my first book.)

At the same time, while the underlying instincts, motives, and emotions may be ingrained and subject to protracted selection, our precise behaviors are much harder to pin on evolution. This is even partially the case for other social mammals, but in humans, cultural evolution has overpowered biological evolution so much and for so long, that natural selection’s fingerprints are extremely blurry. Evolutionary explanations of behavior are highly equivocal.

Over the last 50,000 years, and especially over the last 15,000 years, just about everything about our environment has changed dramatically. Think about how different our daily lives are from that of our ancestors a few hundred years ago. Now consider how different our ancestors from a few thousand years ago. And what about those from tens of thousands of years ago, before agriculture was invented and settlements started.

While that is a long arc in human history, it is the blink of an eye in evolutionary terms. Very little genetic evolution has taken place in that short time. For the most part, we now navigate our very modern world with brains and bodies that were shaped for a completely different existence. Maladaptation is to be expected.

Maladaptation in our bodies is often referred to as “evolutionary mismatch,” and a great deal has been discovered and written about this phenomenon. If you want to read more, I highly recommend Dan Lieberman’s book The Story of the Human Body and I am currently reading (and loving) Vybarr Cregan-Reid’s Primate Change. But evolutionary psychology is a different beast altogether. Spotting maladaptation in our bodies is hard enough, but dissecting our minds and our behaviors is even more so. Again quoting from my essay:

As difficult as it is to apply adaptive and maladaptive interpretations to matters of anatomy and physiology, it is incredibly more so with complex behaviors. The current teleology of a behavior is difficult enough to assess on its own, especially cross-culturally, and the phylogenetic analysis is even more so. Indeed, the substantial behavioral discontinuity between humans and their extant relatives dooms many phylogenetic analyses within human evolutionary psychology.

Nevertheless, science has never been dissuaded from studying something just because it is difficult. Evolutionary psychology is a discipline fraught with challenges and controversy, but most disciplines are. If the answers were easy or obvious, we’d have them already. Science is all about devising creative means to tackle difficult problems, knowing that all discovered knowledge is tentative and no one gets the last word. The process is self-correcting, even if it takes longer than we’d like.

Back to maladaptations in evolutionary psychology. I discuss three possible maladaptive behaviors in my analysis: suicide, honor killing, and adoption. Each of these represent something of a conundrum if we attempt to understand behaviors as simple adaptations (which we shouldn’t anyway). By exploring the ethology of these behaviors, we may better understand them.

Drawing by Jonathan Bartlett http://discovermagazine.com/2015/may/16-days-of-dysevolution

The hope, of course, in analyzing human behavior is to reveal ways in which humanity might benefit from the understanding we gain. Understanding the triggers in our psyche that push us toward certain actions or patterns of behavior can be enormously helpful in undercutting or amplifying those triggers. Our evolutionarily ingrained instincts are very vague and only take shape as behaviors in the context of an environment that heavily shapes them. There are many “levers” that societies can pull to influence how we behave. The entire criminal justice system is based on this idea, but the implications extend far beyond crime and punishment to matters of personal happiness, mental health, stable and thriving families, and the fostering of our unique potential. 

I have high hopes for the future of evolutionary psychology and so I was honored to be invited to contribute to this new encyclopedia project. I am working on two more entries as well, so stay tuned!

Once again, here is the full essay. (And for those who can’t access it, ping me and I’ll send you the PDF.)

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In Michael Behe’s new book, he touts the concept “Devolution” using what he calls the first rule of adaptive evolution, that is, that unguided natural selection usually works through random mutations that damage, diminish, or break the genes in which they occur. To do more than that, the actions of a supernatural intelligent agent are required, according to Behe. (For a more comprehensive review of Behe’s ideas about Intelligent Design, see the first few sections of my recent review of “Darwin Devolves.”)

I have lots of problems with this book. I detail some of them in this review in Science, but I take a detailed scientific look at his opening example in this post, which I think captures Behe’s general approach of presenting data in a very misleading way. But in addition to the problems with his individual claims and examples, the whole concept of “devolution” is rather puzzling and I’d like to expand on that.

You have probably never seen the word “devolution” in a scientific context, because it is not a concept within biological science (as far as I know). Behe uses the terms devolve and devolution to indicate a loss or diminishing of function, as though these were the opposites of evolve and evolution. According to Behe, a protein evolves if it improves in function (or gains a new function), and it devolves if it’s function is reduced, degraded, or destroyed. These are not terms that chemist, biochemists, or molecular biologists use and understand. “Devolve” is a pure Behe-ism.

It also doesn’t make any sense. Evolution simply means change over time, and it is not a steady march toward perfection or increasing complexity. In fact, evolution favors simplicity, efficiency, and streamlining as often as it favors complexity. While it’s possible that Behe is using the term in a jocular manner, there’s no indication of that, and he uses the term repeatedly throughout the book in that very specific way. Let’s call this…

Misunderstanding #1: Behe seems to think that evolution is the accumulation of  complexity. If so, it’s no wonder that he has such angst about it. The reality is that evolution is aimless, sloppy, and produces clunky solutions as often as it does elegant ones. Our own bodies are filled with glitches and goofs left over from the imprecision of natural selection. This may be deeply unsatisfying to some, but nature cares little about our satisfaction.

This fundamental misunderstanding of the nature of evolution is a serious error, especially for someone who has dedicated his career to critiquing modern evolutionary theory. But it not the only one.

Misunderstanding #2: Behe’s notion of “irreducible complexity” demands that natural selection can only work if every single step on an evolutionary path is advantageous. We know that’s not true. Populations of organisms harbor a great deal of genetic diversity generated by gene duplications, neutral mutations (and even slightly deleterious ones), recombination, and even rare but dramatic events like chromosomal duplications or rearrangements, and horizontal gene transfer (which may actually be not as rare as we thought). Evolutionary forces then act on all that diversity in unpredictable ways. In Darwin Devolves, you will not find discussions of any of this. Behe either ignores or quickly dismisses these phenomena, despite the key role they play in the generation of the very complexity that Behe doesn’t think that nature can build.

Misunderstanding #3: Behe frequently speaks as though natural selection (which he often calls Darwinism) is the only evolutionary force. In reality, natural selection is joined by genetic drift, neutral theory, exaptation, gene flow, sexual selection, hybridization, punctuated equilibrium, frequency-dependent selection, and dozens of other forces. Behe constantly repeats his refrain that natural selection cannot account for everything we see in nature. Yeah, we know. And we’ve known that for a very long time.

***

The tendency to see intelligent design in nature is an old one, but science moved past it long ago. As François Jacob wrote in Science over 40 years ago, “Natural selection does not work as an engineer works. It works like a tinkerer — a tinkerer who does not know exactly what he is going to produce but uses whatever he finds around him… to produce some kind of workable object.”

Because he is an accomplished biochemist, Behe’s writing gives the air of scientific authority. However, the answers to the questions he poses have been worked out for quite some time. In 1918, H. J. Muller proposed a process of how natural selection can create complexity: “Add a part; make it necessary.” Behe has long been skeptical of this perhaps because the precise molecular mechanisms of “make it necessary” can be difficult to figure out after the fact.

However, “Muller’s two-step” received a powerful update in 2012, which we now call “Innovation, Amplification, and Divergence,” In this study, Andersson and colleagues showed that, under the right conditions, bacteria would naturally evolve to get over a metabolic hurdle through gene duplication and diversification, all in under 2000 generations. That should have been the end of this debate, but Behe and others insist that this incredible study actually supports Intelligent Design since intelligent scientists designed it. Yes, the scientists were smart, but they designed the way to observe the bacteria’s evolution, they didn’t design the evolution itself.

I find it poetic that the very title of this book, Darwin Devolves, is a misnomer. There is no such thing as devolution and there is no great crisis in evolutionary biology. There are, however, a great deal of interesting unanswered questions. Our new era of cheap genome sequencing can begin to interrogate some of these questions. As with all great interrogations in science, the answers will come from the proper interpretation of all available evidence.

-NHL

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This post was co-authored with Arthur Hunt of the University of Kentucky, who first pointed out some of these errors on the Peaceful Science forum. I wish I had spotted these myself, but I took Behe’s word on the polar bears because it all sounded solid. In other words, I did what Behe hopes all his readers will do – just believe him and not check the reference. Lesson learned and kudos to Art for catching this and for working with me on this post. -NHL

The release of Michael J. Behe’s newest book, Darwin Devolves: The New Science About DNA That Challenges Evolution, is nearly upon us and so the first chapter was made publicly available to entice readers. In this chapter, Behe outlines his main thesis: at the molecular level, adaptive changes are largely due to events that in some way destroy or damage proteins and enzymes. He calls it the first rule of adaptive evolution and to illustrate his point, he discusses the evolution of polar bears and describes the molecular events in that evolution as nothing more than a series of damaging mutations that result in a more adapted organism.

But first, a quick introduction to Behe for those who may not know who Behe is or where this is coming from. With the release of his first book, Darwin’s Black Box, in 1996, Behe helped revolutionize and reorganize the resistance to modern evolution under the banner known as “Intelligent Design,” often abbreviated as ID. Many consider ID as simply creationism by another name, but the ID community works hard to distance themselves from that label. They insist that ID is a scientific theory, not a religious one, based on what they consider evidence that cells and organisms were designed intentionally, rather than the result of the aimless and unguided forces of evolution. Scientists and federal courts disagree, but this has not stopped the steamroller of pseudoscientific claims from the ID community.

Fast forward to 2019 and Behe is at it again. In Darwin Devolves, Behe makes the argument that natural selection, which he prefers to call “Darwinism,” is driven largely, even exclusively, by mutations that degrade or destroy protein function. At the outset, it must be said that we have known for many decades that, occasionally, harming or even destroying a gene or protein can actually be good for the organism. What Behe is saying is that harming genes is the only way that unguided mutations can ever help an organism. That’s just not the case, but I’ll get to that later.

Back to the polar bears. Behe offers them as an example of how harming genes can help an organism and lead to adaptive evolution. Imagine an ancestor bear population that looked pretty much like brown bears. Then came some random mutations that reduced the production or deposition of pigment into the fur of the bears. This made the bears white and – voilà! – the bears acquired natural camouflage in snowy climates so as to better sneak up on their prey.

This seems like a pretty straightforward example and most people will simply take it at face value. Behe jumps from this example to his claim that this is all that unguided mutations can do. However, even in this apparently “pro-Darwinism” example, Behe exaggerates his claims and misrepresents what science has actually revealed. The evolution of polar bears was not only a matter of harmful mutations.

The key reference here is a 2014 paper in Cell. In this study, researchers did genome sequencing of 89 polar bears and brown bears and discovered the molecular changes that distinguish these very closely related species, using the giant panda as the reference sample. The results were fascinating. For example, the analysis revealed that polar bears and brown bears have been separate populations with limited gene flow for less than 500,000 years.

In the polar bears, the researchers found over a dozen protein-coding genes that had experienced recent positive selection, meaning that evolutionary forces had strongly favored specific variants. Brown bears, on the other hand, have experienced much less positive selection since the populations diverged. This means that polar bears have experienced stronger selection and have diverged from the ancestors more than brown bears have. This matches what the fossil evidence suggests. Basically, a population of brown bears ventured northward and, in response to the very different climate, evolved into polar bears. The ancestral population stayed pretty much the same and are the brown bears of today.

One of the genes that experienced the strongest selection is APOB, which encodes apolipoprotein B, a protein involved in the transport of fat molecules in the blood. This makes sense because polar bears subsist on a diet extremely rich in saturated fats, yet don’t develop heart disease with great frequency. Quoting Behe:

The polar bear’s most strongly-selected mutations – and thus most important for its survival – occurred in a gene dubbed APOB, which is involved in fat metabolism in mammals, including humans. That itself is not surprising, since the diet of polar bears contains a very large proportion of fat (much higher than in the diet of brown bears) from seal blubber, so we might expect metabolic changes were needed to accommodate it.

First of all, as shown in Table 1 of the paper, APOB harbors the second most strongly-selected set of variants, not the first, but we can let that one slide.

Behe continues:

But what precisely did the changes in polar bear APOB do to it compared to that of other mammals? When the same gene is mutated in humans and mice, studies show it frequently leads to high levels of cholesterol and heart disease. The scientists who studied the polar bear’s genome detected multiple mutations in APOB. Since few experiments can be done with grumpy polar bears, they analyzed the changes by computer. They determined that the mutations were very likely to be damaging -that is, likely to degrade or destroy the function of the protein the gene codes for.

Some of them, yes. Definitely not all of them or even most of them. He continues:

A second highly-selected gene, LYST, is associated with pigmentation, and changes in it are probably responsible for the blanching of the ancestors’ brown fur. Computer analysis of the multiple mutations of the gene showed that they too were almost certainly damaging to its function. In fact, of all the mutations in the seventeen genes that were most selected, about half were predicted to damage the function of the coded proteins. Furthermore, since most altered genes bore several mutations, only three to six (depending on the method of estimation) out of seventeen genes were free of degrading changes. Put differently, 65-83 percent of helpful, positively selected genes are estimated to have suffered at least one damaging mutation.

Now it’s getting harder to excuse Behe’s exaggeration. Specifically, the authors found that only 7 of the 17 genes with the strongest signatures for positive selection are unequivocally predicted to possess at least one “damaging” mutation. Even Behe’s “about half” is just 41%, which means that the lower limit on Behe’s estimation is also wrong. It’s not 65-83%, it’s 41-83%. The range is so wide because computational predictions invariably involve uncertainty.

But more importantly, by Behe’s math, if a gene harbors five enhancing mutations and one diminishing one (by computer prediction), it counts as “damaged.” Any number of gain-of-function mutations can be overtaken by a single damaging one. While that could be true in some cases, a nonsense mutation for example, there is no reason to assume it must be true in all cases. (Unless, of course, you have a specific argument you’re trying to make.)

Considering how little is known about the molecular biology of polar bears, it is entirely possible that none of the 17 most positively selected genes in polar bears are “damaged.” Quoting from the Supplemental information in the paper:

We find no fixed missense mutations specific to the polar bear lineage associated with human diseases according in the Human Gene Mutation Database. However, the top 20 genes are significantly enriched with genes previously associated with metabolic diseases and traits and humans (p-value = 0.042) from the GWAS catalog, discussed in the main text.

In other words, many of the 20 most positively selected genes in the polar bear genome are orthologs of genes that have variants (mutations) in the human population associated with metabolic disease. So when these genes are damaged by mutations in humans, the humans are more likely to suffer metabolic diseases. But Behe believes – with no hard evidence mind you! – that these same genes, when damaged, protect the polar bears from metabolic disease.

And there’s more. If we come back to APOB, the polar bear gene that Behe spends the most time discussing, we find that the authors of the study have a very different interpretation of the data than Behe does. Quoting the paper again [emphasis added]:

Substantial work has been done on the functional significance of APOB mutations in other mammals. In humans and mice, genetic APOB variants associated with increased levels of apoB are also associated with unusually high plasma concentrations of cholesterol and LDL, which in turn contribute to hypercholesterolemia and heart disease in humans (Benn, 2009; Hegele, 2009). In contrast with brown bear, which has no fixed APOB mutations compared to the giant panda genome, we find nine fixed missense mutations in the polar bear (Figure 5A). Five of the nine cluster within the N-terminal ba1 domain of the APOB gene, although the region comprises only 22% of the protein (binomial test p value = 0.029). This domain encodes the surface region and contains the majority of functional domains for lipid transport. We suggest that the shift to a diet consisting predominantly of fatty acids in polar bears induced adaptive changes in APOB, which enabled the species to cope with high fatty acid intake by contributing to the effective clearance of cholesterol from the blood.

Clearly, the authors do not expect the polar bear APOB to be “broken.” Rather, a bare majority of the amino acid changes are in the most important region for the clearing of cholesterol from the blood. In other words, these mutations likely enhance the function of apoB, at least when it comes to surviving on a diet high in saturated fats.

It is also worth noting that apoB does much more than clear fatty acids from the blood. It is a very large protein that has many biochemical activities and is a central player for lipid and cholesterol transport. Even if “damaging” mutations might be beneficial in one context, they could very well be harmful or lethal in another. Moreover, mice that lack apoB are not viable.

To recap: 1.) There is no evidence for Behe’s claim that APOB is degraded or diminished in polar bears and everything we know about the protein from other mammals suggest the opposite. And 2.) Behe’s claim that the most common adaptive changes in polar bears are those that degrade or destroy proteins is not supported, and the evidence suggests otherwise. Those are just the errors that we found in his first example.

And yet Behe makes this bold claim:

It seems, then, that the magnificent Ursus maritimus has adjusted to its harsh environment mainly by degrading genes its ancestors already possessed. Despite its impressive abilities, rather than evolving, it has adapted predominantly by devolving. What that portends for our conception of evolution is the principal topic of this book.

If you are wondering what the word “devolving” means, join the club. I’ll leave that discussion for another day.

For more of the problems with Darwin Devolves, see my review in Science (co-authored with Richard Lenski and Josh Swamidass, open-access version), my essay in Skeptic magazine (available in a couple weeks), and my book review in AiPT!

-NHL (with special guest, Art Hunt)

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[This essay first appeared in Arc Digital and was co-authored by Nathan H. Lents and Robert Trivers. Credit for the thesis and most of the evolutionary analysis belongs to Trivers.]

There is no shortage of published psychological profiles of Donald J. Trump that attempt to diagnose him, from a distance, as either a psychopath or a narcissistic sociopath (examples herehere, here, here, here, and here). These profiles, of course, are fatally hindered by the lack of access to Mr. Trump for personal examination and completion of personality inventories. However, exploration of the evolutionary features of these very peculiar personality types provides insight into this important question.

Psychopaths are indeed an evolutionary conundrum because their particular behaviors are not an obvious path toward evolutionary success. For example, the majority of serial killers are childless when they are killed or apprehended. Narcissistic sociopaths, however, invariably have families and children whom they support energetically, and many of the traits specific to this phenotype can fairly be called adaptive. This raises the important issue of the evolutionary niche of a narcissistic sociopath within the societies in which they exist.

[A note on terminology: We employ “narcissistic sociopath” as an umbrella term inclusive of Machiavellianism and narcissistic/antisocial personality disorder but exclusive of sadistic psychopathology, as explained below. Terminology in this area is inconsistent in both the scientific literature and even more so in popular media, in part because these various personality types/disorders exist on a multidimensional spectrum with both common and distinct characteristics. Importantly, our analysis is from the perspective of evolutionary biology, not psychology.]

Narcissistic sociopaths share many features with psychopaths including above average intelligence, considerable social savvy, adaptability, likeability, and natural skills in manipulation (Machiavellianism). They are charming, outgoing, feign interest in people and subjects, and can convincingly fake both sympathy and conscience. If they engage in charitable acts at all, they are only in pursuit of ancillary selfish benefits. They learn from experience, and show no dedication to a set of moral values, religious beliefs, truth, or transparency. If they admire anyone, it is other psychopaths and sociopaths that they wish to emulate. Finally, they are effective liars and show a chilling unconcern for the welfare of others.

There is one particular skill that is common to both psychopaths and narcissistic sociopaths and is absolutely essential to their nature: cognitive empathy. This is different from emotional empathy, sometimes called emotional contagion, which is regarded as the ability and tendency to closely identify with the emotional experience of others. Cognitive empathy is a mental skill involving the close observation of others in order to understand and predict their behavior. It is morally neutral and common in high-functioning individuals across the moral and ethical spectrum. While social workers and therapists use cognitive empathy to help individuals improve their lives, psychopaths and sociopaths use this skill to manipulate, coerce, and deceive others in orders. While emotional empathy is an innate cognitive feature we share with other social mammals, cognitive empathy is a skill that can be developed and refined, and doing so is key to the behaviors of both psychopaths and sociopaths.

However, the ways in which sociopaths differ from psychopaths is key to understanding their evolutionary utility. For example, psychopaths are more likely than the general public to be violent and to end up incarcerated. Narcissistic sociopaths, on the other hand, are usually nonviolent and can work within a system of laws and norms, insofar as it suits their goals, because, while they do not hesitate to harm others, especially when insulted or humiliated, it isn’t a specific aim. Instead, they are highly motivated toward the accumulation of riches and influence; whereas psychopaths are often more focused on sadistic self-gratification and generally do not seek positions of power and wealth per se. (There is some crossover between these phenotypes; sociopaths who do find gratification in inflicting pain can be labeled malignant narcissists.)

Finally, narcissistic sociopaths always seek reproductive success through procreation and aggressive nepotism, which is usually accompanied by extreme in-group identification, e.g., racism, xenophobia, and nationalism, while psychopaths show no allegiance to family, community, or country.

Therefore, the phenotype of the narcissistic sociopath is not a bizarre combination of traits, but rather a set of highly attuned social skills and behaviors aimed at increasing long-term biological fitness through wealth, status, power, and the future success of progeny. In order words, sociopaths are highly adapted (key literature here, here, here, and references therein).

The evolutionary puzzle of narcissistic sociopaths is not found in the phenotype itself but rather in the interaction of sociopaths with the society in which they exist. Social groups can detect dishonest and manipulative behaviors and act to punish the actors in order to either correct the antisocial behavior or remove them from the group. Dozens of mammal species have shown this very sophisticated and elastic social behavior, but humans and our close relatives are especially apt at detecting and punishing cheaters, freeloaders, and liars.

This sets up both a short-term conflict and long-term evolutionary battle between manipulative narcissistic sociopaths and the rest of society, that is, those who do not wish to be manipulated. Most individuals in a society share a vested interest in maintaining fairness and social order. The equilibrium point is reached through a concept called frequency-dependent selection, the essence of which is that phenotypes can sometimes have distinct advantages precisely because they are rare. Under this paradigm, the infrequency of sociopaths in a population is essential to their success.

Current estimates place the prevalence of narcissistic sociopathy at 1–2 percent, making it a candidate phenotype for frequency-dependent selection, especially given how successful they often are. The rarity of narcissistic sociopaths in the population, along with their considerable skill in hiding their true motivations, makes them very difficult to detect. If they were more numerous, however, members of society would become familiar with this particular pattern of social deviance and quickly learn to neutralize it. Furthermore, when narcissists encounter one another, while they may be willing to cooperate with each other in fickle and short-lived alliances, ultimately their goals will collide and the relationship deteriorates into mutually self-defeating conflicts. This, too, acts as negative selection and maintains the low frequency of this peculiar phenotype.

On the other side of the conflict is the selective pressure on the rest of society. Because sociopaths are rare, the intensity of the pressure on society to detect and neutralize them is correspondingly weak. Weak pressure leads to poor adaptation, while sociopaths experience strong pressure and become highly adapted. However, as the sociopath phenotype finds evolutionary success, the pressure flips back the other direction as the rest of society experiences increasing pressure, adapts, and then pushes the frequency of the sociopaths back down to the basal level. In human culture, this pendulum swings in both the long time scales of genetic evolution and the short time scales of cultural evolution. In both contexts, the conflict is cyclical.

With this evolutionary framework in mind, we can now return to the question of President Trump. Clearly, he attracts devoted supporters. He can be affable, charming, and flattering. He reads people well and can maneuver through his relationships in order to obtain the best “deal” for himself. While many question his capacity for emotional empathy, his skills in cognitive empathy are undeniable.

However, he also has maintained an unwavering pursuit of wealth, influence, and power, by his own admission. He has never participated in regular religious observance, is not outwardly pious, and shows no allegiance to political party. It is well documented that his views have shifted, sometimes repeatedly, on the most central political questions of the day such as abortion, government involvement in healthcare, military interventionism, federal drug policy, and LGBTQ rights. While only his critics view him as racist and xenophobic, even his supporters see him as fiercely nationalistic and his own campaign slogan of “America First” underscores this. And finally, he aggressively pursues his own biological fitness through the placement of his children in top positions in both his business enterprises and his presidential administration. Thus, an evolutionary analysis reveals that he is clearly not a psychopath.

Whether or not he is a narcissistic sociopath, then, depends on the answers to questions about his conscience or lack thereof, commitment to truth and transparency, sincerity in his professed religious beliefs, fidelity to political ideals, and tendency to cheat, deceive, and coerce. These questions are more like Rorschach tests in which his supporters and detractors come to opposite conclusions. However, for the most part, the answers to these questions do not require a psychological analysis of the president. There is abundant evidence in the public record.

[This analysis reflects the views of biologists Nathan H. Lents and Robert Trivers, not any of the institutions they are or have been affiliated with.]

-NHL

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Are mutant the next step in evolution? Yes!  (But not like that.)

[This essay first appeared in AiPT!.]

In the Marvel universe, the X-men are a special class of human beings called mutants, so called because they harbor mutations gifting them with various superhuman abilities. Each hero has a particular superpower generated, presumably, by specific mutations in their genomes.

Stan Lee (peace be upon him), Jack Kirby, and the other Marvel writers “took the cowardly way out” (their words) and chose not to think up elaborate origin stories for these heroes, and instead pinned their abilities to unnamed mutations. We can only speculate about the underlying anatomy and physiology of these super powers. And speculate we will.

What are mutations?

But first, a word about mutations. Lee was definitely on to something when he posited that mutations were the way to deliver new abilities to an otherwise run-of-the-mill human being. In fact, mutations have been the vehicle of all evolutionary innovation since the first proto-cells floated aimlessly through the primordial soup. That’s an understatement, actually, because mutations have been the source of all heritable changes, innovative and mundane – and the mundane far outnumber the innovative – in all lineages of life.

 Mutations are most often the result of copying errors during the process of DNA synthesis. Every time a cell divides, it must first copy its DNA so that both daughter cells get all the genetic instructions. The copying mechanisms are pretty darn good so mistakes are rare, but they do happen. And when they do, they are almost completely random. This is as true in the simplest cells on earth as it is in our elaborate ones. Most mutations are harmless, however, and we all have them. In fact, each of us adds a couple hundred new mutations to the human gene pool. If Dr. Bolivar Trask’s “mutant detector” from X-men: Days of Future Past were ever actually fired up, it would go off constantly. 

The X-genes

In the case of the X-men, the mutations in question are those that unlock the function of previously dormant “X-genes.” This, too, is based on a real biological phenomenon. Mutations that activate or deactivate a previous mutation are called spontaneous revertantsand these individuals, while incredibly rare, probably played key roles throughout evolutionary history. Scientists have generated many spontaneous revertants in laboratories including chickens with teeth (bird ancestors lost their teeth over 80 million years ago). More helpfully (and less frighteningly), scientists have activated a dormant gene that enhances oxygen transport by hemoglobin, a technique that may help treat a variety of anemia-causing diseases. And revertants are not limited to laboratory creations. A wild dolphin with “hind fins” was discovered in in the Pacific Ocean in 2006 (dolphin ancestors lost their hind limbs 40 million years ago).

Mutations that occur in regular cells of your body, even if they do something great for you, are not the engines of evolution because you don’t pass those on. Only mutations in the germ line – the cells that give rise to sperm and eggs – matter in the long run. So, in real life, an evolutionary “mutant” didn’t actually experience said mutation herself: one of her parents did in their gonads. (A women’s eggs are mostly pre-formed way back when she was an embryo in utero herself, so a maternally inherited mutation is one that occurred when one’s grandmother was pregnant with their mother!)

But X-men don’t get their powers until puberty. To get around the problem that mutations in regular body cells can’t “spread” to other tissues, it was explained that when the X-genes are first activated (in which tissue, we’re not told), they express proteins that subsequently mobilize, making further mutations and alterations in genes and cells throughout the body. While this scenario is exceedingly far-fetched, it’s reminiscent of a principle that we now recognize as epigenetics: some factors can affect the expression of other genes in a stable, cascading, and even heritable way. Presciently, this X-men form of super-genetic inheritance was first discussed in the X-men comics in the 1960s, a full 30 years before the scientific community began to appreciate epigenetics.

How do genes give rise to powers?

To discuss how these mutations have their dramatic “EX-tra powers,” we have to fully depart from scientific reality. In the real world of evolutionary history, mutations are random and generally emerge one-at-a-time. This means that mutations can only make the tiniest tweaks and tugs in the bodies in which they occur.

Going from no wings to fully formed wings in one generation is simply not anatomically possible, even theoretically. Besides the creation of new anatomy out of whole cloth (something that never happens), it would also require dramatic changes in the nearby skeleton, musculature, nerves, and connective tissues. And don’t forget the requisite changes in the brain! The mutants will need new neural circuitry in order to operate their new features. Again, this is way more work than mutations can do, even millions of simultaneous ones.

In fact, growing whole new structures is so rare that it has hardly ever happened, over the entire half billion years of animal evolution. In vertebrates, wings have evolved three separate times – in birds, bats, and pterosaurs – but all of these involved the reshaping of the pre-existing forelimbs, not the growth of new appendages from nothing. Yet, growing entirely new structures is the hallmark of our X-men.

Of course science fiction is not meant to be perfectly accurate in its scientific content – that’s the “fiction” part and also what makes it fun. However, there is one error that is based on a misconception so heretical and so widespread that it simply must be called out every time. The mutant Armando Muñoz gets the nickname “Darwin” because he can adapt – biologically, no less – to any new environmental challenge that he’s faced with.

This is basically the opposite of how evolution works. Individuals do not, indeed cannot, adapt. Populations adapt over many generations when the randomness of mutation collides with the non-randomness of natural selection. Further, the act of presenting an environmental challenge to a population doesn’t make them adapt. Instead, they must wait around for the rare and random mutation that helps them in some tiny way and then, over time, they can begin to adapt. It’s a slow, aimless, and utterly unsatisfying process.

The rules are obviously different with these fancy X-genes, but this ill-suited namesake would make Darwin roll in his grave precisely because of how hard he worked to differentiate his theory from prior ideas that posited, incorrectly it turns out, that individuals can adapt.

The inheritance of the X-genes

Professor X once claimed that the X-gene itself is on the X chromosome (because of course it is). But this creates a major problem for the inheritance of mutant abilities. While female mutants can pass their X-gene on to both sons and daughters, male mutants would only pass their mutation on to their daughters because fathers pass only their Y chromosome to their sons, not their X. Since Magneto is known to have sons with his same abilities (e.g., Quicksilver), Professor X must have been wrong about the location of the X-genes after all.

An interesting question is how different mutant superpowers would combine in individuals with two mutant ancestors. The fantasy is that all the powers would accumulate as the mutant family trees entangle. However, this assumes that the various mutations involved will harmoniously comingle in the body. It’s much more likely that they will counteract each other in destructive ways.

For example, in order to effectively manipulate magnetic fields, Magneto needs a reorganization of his cerebral cortex and probably other brain regions also. Those same brain centers would likely be required to operate other mutant powers and so the mutations become incompatible at the level of brain tissue architecture. Given many generations of selective pressure, evolution can often find solutions to these kinds of problems (after all, most of us can walk and chew gum at the same time), but the hybrid mutants would have diminished use of their superpowers in the meantime, reducing any evolutionary advantage.

The “next step in evolution”

Speaking of evolutionary advantage, the concept of the X genes, and especially the nickname, “the next step in evolution,” is more in line with misconceptions about evolution than with the reality. Evolution is aimless, sloppy, and settles on compromises infinitely more often than it develops innovation. There is no directionality to evolution whatsoever and, since the environment is always changing also, most species are doing all they can to simply avoid extinction. Too often, “evolution” is equated with increases in function, complexity, and creativity, but the opposite is more often true: evolution can lead a species toward efficiency and simplicity.

Sure, us “big” species, like humans, whales, and redwoods, get all the attention, but the vast majority of living things on this planet are the single-celled prokaryotes, bacteria and archaea. If any creature should be considered the “pinnacles of evolution,” shouldn’t it be them? They have successfully mastered every conceivable niche on our planet, from pressurized scalding water, to the dark depths many miles below the planet’s surface. They are, by far, the majority of the individuals on the planet and they outnumber us even on our bodies: prokaryotic cells outnumber human cells in the human body, possibly two-to-one!

The final word on the evolutionary biology of the X-men mutants involves their reproductive success. Even if the almost infinite number of required mutations could theoretically reshape their bodies and brains as needed, and even if all of this happened in a single individual, and even if the sperm or eggs were altered as well so that the changes were made heritable, we still have a problem. Evolutionary innovation requires that the bearer of the innovation pass the gene down to descendants that outcompete, that is, out-reproduce those that have less favorable combinations of traits. Successful reproduction is the key. In addition to the enviable superhuman abilities of our mutant X-men, many of them have another quirk that we can’t ignore: many of them are anti-social.

The X-men that keep to themselves and shun romantic contact effectively take themselves out of the gene pool. This means that the mutations that seem so clearly beneficial have a fatal flaw: they also make them unlikely or unable to reproduce. On the other hand, some X-men appear to be quite fecund. Wolverine and Magneto have the most offspring, with dozens of children each (though many are in alternate timelines). Over future generations, their unique combinations of mutations will successfully enter the gene pool. If their offspring are similarly prolific, these traits have a real chance of spreading through the human population in future generations.

But for the majority of X-men, it seems that all of those wondrous mutant abilities will simply die with those that bear them. Even if the X-men themselves are immortal – because hey, anything is apparently possible – their mutations still won’t spread to the population at large. This is not adaptation; it is maladaptation. Any creature that does not reproduce is considered an evolutionary dead-end.

So much for being the next step in evolution.

[This essay first appeared in AiPT!.]

-NHL

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[This essay first appeared in Adventures in Poor Taste!]

I’ve been thinking a lot about design and imperfection lately.

Somewhere in the fog of that reflection, I found myself on the main stage of the Ars Electronica Festival, a truly global exhibition of digital art. This annual showcase in Linz, Austria has seen the premier of some of the world’s most provocative and innovative electronic art for nearly 40 years. Why was a biologist speaking at a digital art festival? This year the theme was Error: The Art of Imperfection and I guess I am becoming a go-to guy for a talk on human flaws.

Nevertheless, in all my research on defects in the human body, I never once thought about them as artful. Where is the art in achy backs, junky DNA, and high infant mortality? However, surrounded by stunning works of art and brilliant artists and scholars, the inherent beauty of our very human flaws suddenly struck me. Although beauty is often understood as an expression of perfection, this is all wrong: it is imperfection that leads to beauty.

The opening lines of the conference program discussed the typical process of making mistakes while working on an art project. How do we know if it is an error or an innovation? Is it a goof-up to be corrected or the beginning of something great? Although this was meant to be read in the context of art and design, it is also a poetic way to think about the root of all innovation in living systems: mutations.

Mutations in genetic material most often begin as DNA copying errors, mistakes in the purest sense. Because they are purely random, these mistakes are often bad, and even more often neutral. But occasionally, very rarely in fact, a mutation comes along that gives new function, new meaning, to a gene. These extraordinary mutations are the raw material of all of the great diversity of the living world, of everything that moves and breathes and gives birth to new life.

This image gives examples of the most common kinds of mutations in DNA using letters and words as analogous to the nucleotides and codons of DNA.

From the simplest microbes to the towering redwoods, it all began with a mistake. And then another. And then another. Out of this swarming chaos emerged everything that lives – including us – not unlike the majestic Grand Canyon that sprang forth from nothing more than rock, water, and whole lot of time.

Homo sapiens has a very long history and because we weren’t writing things down until recently, we have to work very hard and very creatively in order to piece that history together. Fortunately, modern science has developed a variety of clever tools that help us discover our past and begin to make sense of it. There is great value in understanding the forces that shaped us into the wonderful and flawed species that we are. By better understanding our past, we better understand ourselves.

Often, we think of fossils when we consider our biological past. Fossils are indeed crucial for tracing our evolutionary history and the anatomy, physiology, and even behavior of our forebears. However, lucky for us, we can also gain insights by examining our bodies as they are right now because we bear the scars of our past selves. Our diseases are like echoes of ancient battles. Our genomes hide the carnage of vanquished viral foes. Even the quirks of the human mind reveal something about the world in which we once lived. Some of our idiosyncrasies are actually anachronisms, like windows into our distant past.

One exciting way to make sense of the human animal, the most unlikely of creatures, is through scrutinizing our shortcomings. While the human body is indeed a marvel, it is far from perfect. For example, we have nasal sinuses that drain upward, genes that don’t work, nerves that take bizarre paths, and muscles that attach to nothing. While these can fairly be called flaws, they are not flukes and, in most cases, they do not defy explanation. Rather, our many glitches hide fascinating tales of the lives our ancestors once lived. Ours is a history of triumph against all odds.

But, you might ask, how could these flaws have come about? Yes, mutations are random and often harmful, but isn’t it the job of natural selection to weed out those mistakes and march us toward perfection? Unfortunately not. As our many human errors make clear, evolution is clumsy, aimless, and utterly indifferent. We are not evolved to be healthy or happy or comfortable. We have evolved only to survive and reproduce. Evolution is a game of cruel compromises and sloppy trade-offs. What more can we expect from a process that works through the randomness of mutations?

Consider the demands of the human diet. We require a wide variety of foods in order to be healthy, far more so than other animals, who can often subsist on just one or two foods their entire lives. This is partly because, for most of our history, we were living in a veritable salad bowl, surrounded by a cornucopia of nutritious food. We then supplemented that with foraging behaviors, adding even more variety. In the process, we lost the ability to make many vitamins and other nutrients for ourselves. Our dietary need for vitamins C, D, and B12 each reveal a different kind of flaw in our metabolism.

Far worse even than that, the main staple foods throughout world cultures are derived from plants intentionally cultivated and shaped by our ancestors. These plants are starchy crops that our bodies are not well suited to subsist on. While it would be unfair to pin this imperfection on evolution, because, in a sense, we did this to ourselves, it does show the limits of our biology and the way in which our past shapes our present.

The one thing that you might think we have mastered, given how global our proliferation has been, is reproduction. But, in fact, a shocking number of us struggle with infertility. This is no surprise when you consider that our ovaries are not secured to our fallopian tubes, our sperm cells cannot turn left, and our embryos frequently end up with the wrong number of chromosomes. Before modern medicine, it was shockingly common for the mother or the baby – or both! – to die during childbirth or soon thereafter. This is a fate very rarely suffered by our fellow apes. Of course, the tension between our enormous skulls and narrow pelvises is mostly to blame, but many other things can go wrong with our reproduction as well. It’s a wonder we’ve made it this far.

But we have made it this far. Our flaws also speak to our greatness. Part of why we have so many glitches is that we are very good at getting around them. By evolving a big brain, we took the pressure off our body to be perfect. Using our body alone, we could never live in climates from the Sahara to Antarctica, but by using our brain, we can thrive almost anywhere. From the hand axe to the smart phone, we have a long history of using technology to augment the limits of our bodies.

If pressed to take an opinion on whether humans have more physical and genetic flaws than other animals, I would have to answer in the affirmative. We really do seem glitchier than our animal cousins. This is more good news. Only a species with a social structure as tightly woven as ours could ever have survived with bodies this limited. If your eyesight is no good for hunting, perhaps you can be a homesteader. If you are too sickly for child rearing, maybe you can craft tools or clothing. If your body is too worn or crippled, your wisdom or cleverness is still of great value to your people. We descend from a long line of not just hunters and gathers, but shamans and seamstresses, nannies and tradesmen, artisans and bureaucrats. Our ancestors were dreamers and planners, and who would want it any other way?

Rather than doom and gloom, a full accounting of our glitches and limitations provides clues on how to live in better harmony with a body that was shaped for a very different world. Despite our many flaws, we have accomplished so much that is worth fighting for. Expecting our bodies or minds to be perfect is not reasonable, but fortunately, evolution’s standards are much lower than that. All we must do to continue to thrive is to learn from our mistakes. But before we can learn from them, we must acknowledge them. Personally, I go further than that. I celebrate them.

Of all the species that have ever walked the earth, we may be the most flawed, but we are certainly the most beautiful.

-NHL

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