David Dobbs writes: A couple of years ago, at a massive conference of neuroscientists — 35,000 attendees, scores of sessions going at any given time — I wandered into a talk that I thought would be about consciousness but proved (wrong room) to be about grasshoppers and locusts. At the front of the room, a bug-obsessed neuroscientist named Steve Rogers was describing these two creatures — one elegant, modest, and well-mannered, the other a soccer hooligan.
The grasshopper, he noted, sports long legs and wings, walks low and slow, and dines discreetly in solitude. The locust scurries hurriedly and hoggishly on short, crooked legs and joins hungrily with others to form swarms that darken the sky and descend to chew the farmer’s fields bare.
Related, yes, just as grasshoppers and crickets are. But even someone as insect-ignorant as I could see that the hopper and the locust were wildly different animals — different species, doubtless, possibly different genera. So I was quite amazed when Rogers told us that grasshopper and locust are in fact the same species, even the same animal, and that, as Jekyll is Hyde, one can morph into the other at alarmingly short notice.
Not all grasshopper species, he explained (there are some 11,000), possess this morphing power; some always remain grasshoppers. But every locust was, and technically still is, a grasshopper — not a different species or subspecies, but a sort of hopper gone mad. If faced with clues that food might be scarce, such as hunger or crowding, certain grasshopper species can transform within days or even hours from their solitudinous hopper states to become part of a maniacally social locust scourge. They can also return quickly to their original form.
In the most infamous species, Schistocerca gregaria, the desert locust of Africa, the Middle East and Asia, these phase changes (as this morphing process is called) occur when crowding spurs a temporary spike in serotonin levels, which causes changes in gene expression so widespread and powerful they alter not just the hopper’s behaviour but its appearance and form. Legs and wings shrink. Subtle camo colouring turns conspicuously garish. The brain grows to manage the animal’s newly complicated social world, which includes the fact that, if a locust moves too slowly amid its million cousins, the cousins directly behind might eat it.
How does this happen? Does something happen to their genes? Yes, but — and here was the point of Rogers’s talk — their genes don’t actually change. That is, they don’t mutate or in any way alter the genetic sequence or DNA. Nothing gets rewritten. Instead, this bug’s DNA — the genetic book with millions of letters that form the instructions for building and operating a grasshopper — gets reread so that the very same book becomes the instructions for operating a locust. Even as one animal becomes the other, as Jekyll becomes Hyde, its genome stays unchanged. Same genome, same individual, but, I think we can all agree, quite a different beast.
Transforming the hopper is gene expression — a change in how the hopper’s genes are ‘expressed’, or read out. Gene expression is what makes a gene meaningful, and it’s vital for distinguishing one species from another. We humans, for instance, share more than half our genomes with flatworms; about 60 per cent with fruit flies and chickens; 80 per cent with cows; and 99 per cent with chimps. Those genetic distinctions aren’t enough to create all our differences from those animals — what biologists call our particular phenotype, which is essentially the recognisable thing a genotype builds. This means that we are human, rather than wormlike, flylike, chickenlike, feline, bovine, or excessively simian, less because we carry different genes from those other species than because our cells read differently our remarkably similar genomes as we develop from zygote to adult. The writing varies — but hardly as much as the reading.
This raises a question: if merely reading a genome differently can change organisms so wildly, why bother rewriting the genome to evolve? How vital, really, are actual changes in the genetic code? Do we even need DNA changes to adapt to new environments? Is the importance of the gene as the driver of evolution being overplayed?
You’ve probably noticed that these questions are not gracing the cover of Time or haunting Oprah, Letterman, or even TED talks. Yet for more than two decades they have been stirring a heated argument among geneticists and evolutionary theorists. As evidence of the power of rapid gene expression mounts, these questions might (or might not, for pesky reasons we’ll get to) begin to change not only mainstream evolutionary theory but our more everyday understanding of evolution. [Continue reading...]
Paul Davies writes: The recent announcement by a team of astronomers that there could be as many as 40 billion habitable planets in our galaxy has further fueled the speculation, popular even among many distinguished scientists, that the universe is teeming with life.
The astronomer Geoffrey W. Marcy of the University of California, Berkeley, an experienced planet hunter and co-author of the study that generated the finding, said that it “represents one great leap toward the possibility of life, including intelligent life, in the universe.”
But “possibility” is not the same as likelihood. If a planet is to be inhabited rather than merely habitable, two basic requirements must be met: the planet must first be suitable and then life must emerge on it at some stage.
What can be said about the chances of life starting up on a habitable planet? Darwin gave us a powerful explanation of how life on Earth evolved over billions of years, but he would not be drawn out on the question of how life got going in the first place. “One might as well speculate about the origin of matter,” he quipped. In spite of intensive research, scientists are still very much in the dark about the mechanism that transformed a nonliving chemical soup into a living cell. But without knowing the process that produced life, the odds of its happening can’t be estimated.
When I was a student in the 1960s, the prevailing view among scientists was that life on Earth was a freak phenomenon, the result of a sequence of chemical accidents so rare that they would be unlikely to have happened twice in the observable universe. “Man at last knows he is alone in the unfeeling immensity of the universe, out of which he has emerged only by chance,” wrote the biologist Jacques Monod. Today the pendulum has swung dramatically, and many distinguished scientists claim that life will almost inevitably arise in Earthlike conditions. Yet this decisive shift in view is based on little more than a hunch, rather than an improved understanding of life’s origin. [Continue reading...]
UCLA Newsroom: Why do the faces of some primates contain so many different colors — black, blue, red, orange and white — that are mixed in all kinds of combinations and often striking patterns while other primate faces are quite plain?
UCLA biologists reported last year on the evolution of 129 primate faces in species from Central and South America. This research team now reports on the faces of 139 Old World African and Asian primate species that have been diversifying over some 25 million years.
With these Old World monkeys and apes, the species that are more social have more complex facial patterns, the biologists found. Species that have smaller group sizes tend to have simpler faces with fewer colors, perhaps because the presence of more color patches in the face results in greater potential for facial variation across individuals within species. This variation could aid in identification, which may be a more difficult task in larger groups.
Species that live in the same habitat with other closely related species tend to have more complex facial patterns, suggesting that complex faces may also aid in species recognition, the life scientists found.
“Humans are crazy for Facebook, but our research suggests that primates have been relying on the face to tell friends from competitors for the last 50 million years and that social pressures have guided the evolution of the enormous diversity of faces we see across the group today,” said Michael Alfaro, an associate professor of ecology and evolutionary biology in the UCLA College of Letters and Science and senior author of the study.
“Faces are really important to how monkeys and apes can tell one another apart,” he said. “We think the color patterns have to do both with the importance of telling individuals of your own species apart from closely related species and for social communication among members of the same species.” [Continue reading...]
I recently offered some commentary on a scientific paper, “Life before Earth,” written by a couple of geneticists, Alexei Sharov of the National Institute on Aging in Baltimore, and Richard Gordon of the Gulf Specimen Marine Laboratory in Florida, who suggest that the rate at which evolution advances necessitates that life must be much older than the Earth and may trace back to within the first 2 billion years of the universe’s existence.
Sharov and Gordon base their analysis on the claim that genetic complexity advances exponentially and they draw a comparison with Moore’s law which, though not actually a law, describes the fact that roughly every two years semiconductor manufacturers are able to double the number of transistors that can be crammed onto a microprocessor. Sharov and Gordon say that genetic complexity doubles every 376 million years.
The idea that life began long before the existence of our planet is certainly a view well outside orthodox views of evolution. And science is inherently conservative in its approach to radical new ideas. So, the fact that Sharov and Gordon’s paper has either been ignored or dismissed does not in and of itself indicate it is worthless.
However, I’m not a geneticist, so I’m not in a position to provide any critical analysis on what they wrote. Massimo Pigliucci, on the other hand, is a rare combination: he’s both a geneticist and a philosopher. So, unlike some other scientists, he doesn’t contemptuously dismiss the paper, but he does have the wherewithal to pick it apart.
[T]he first highly questionable statement … is that “the core of the macroevolutionary process … is the increase of functional complexity of organisms.” No, it isn’t. Stephen Gould long ago persuasively argued that there is no necessary direction of increased complexity throughout evolution. The only reason why complexity historically follows simplicity is because life had to start simple, so it only had “more complex” as a direction of (stochastic, not directed) movement. It’s a so-called “left wall” effect: if you start walking (randomly, even) from near a wall, the place you end up is away from the wall. And of course, as Gould again pointed out, life on earth was (relatively) simple and bacterial for a long, long time — and none the worse for it either. Moreover, the most complex organism on earth — us — though very successful in certain respects, is actually a member of a very small and often struggling group of large brained social animals. Measured by criteria such as biomass, bacteria still beat the crap out of us “superior” beings.
But the real problems begin for the Sharov and Gordon paper when they finally get to the business at hand: correlating genomic complexity with time of origin of the respective organisms, and then extrapolating back in time. [As a commenter on my Twitter stream pointed out, they could just as “reasonably” have extrapolated into the far future, arriving at the conclusion that the entire universe will eventually be made of DNA...]
The authors realize that simple genome length won’t cut it, because what matters is functional complexity, and there are some portions of the genomes of various organisms that are redundant and possibly without function. Nonetheless, they end up plotting the log-10 of genome size against time, which is how they arrive at the figure of 9.7 billion years ago for the origin of life. As PZ Myers quickly pointed out, however, even if we accept the procedure at face value, they simply cherry picked the data: plenty of organisms that don’t show up on the graph (plants and fungi, for instance) would completely scramble the results. Make no mistake about it: this is a fatal blow to the entire enterprise, and one that the authors ought to have thought about well before posting the paper. [Continue reading...]
The Telegraph reports: The apes, which are our closest relatives in the animal kingdom, seem to get the same level of satisfaction out of solving brain teasers as their human evolutionary cousins.
A study published by the Zoological Society of London shows that six chimpanzees who were given a game which involved moving red dice or Brazil through a maze of pipes enjoyed solving the puzzle whether they got a reward or not.
The researchers claim this suggests they got the same kind of psychological reward as humans get when solving problems.
Most problem solving witnessed in the animal kingdom, where animals use tools or navigate mazes, are with the aim of reaching food. Hyenas, octopuses and birds such as crows all show the ability to solve problems.
Chimpanzees have also been witnessed in the wild using tools such as a stick to forage for insects or honey in hard to reach places like tree stumps.
But ZSL researcher Fay Clark said their research said they could be motivated by more than just food.
She said: “We noticed that the chimps were keen to complete the puzzle regardless of whether or not they received a food reward.
“This strongly suggests they get similar feelings of satisfaction to humans who often complete brain games for a feel-good reward.”
It seems like research repeatedly demonstrates that we share more similarities with other primates than we previously recognized, and as I’ve suggested before, this says as much about our preconceptions about human uniqueness as it says about the human-like qualities of our close relatives. Moreover, in this case, just as the research indicates chimps experience a human-like satisfaction in problem-solving, I suspect that in both instances this trait relates to something shared by all animate creatures: an interest in discerning order.
Chaos is immobilizing and the ability to turn one direction rather than another rests in part in the ability to see patterns and repetition. In pure pristine perception, every moment would be unique, but in reality, the ground of perception is not blank — present is mapped onto past.
Ed Yong writes: Genomes are often described as recipe books for living things. If that’s the case, many of them badly need an editor. For example, around half of the human genome is made up of bits of DNA that have copied themselves and jumped around, creating vast tracts of repetitive sequences. The same is true for the cow genome, where one particular piece of DNA, known as BovB, has run amok. It’s there in its thousands. Around a quarter of a cow’s DNA is made of BovB sequences or their descendants.
BovB isn’t restricted to cows. If you look for it in other animals, as Ali Morton Walsh from the University of Adelaide did, you’ll find it in elephants, horses, and platypuses. It lurks among the DNA of skinks and geckos, pythons and seasnakes. It’s there in purple sea urchin, the silkworm and the zebrafish.
The obvious interpretation is that BovB was present in the ancestor of all of these animals, and stayed in their genomes as they diversified. If that’s the case, then closely related species should have more similar versions of BovB. The cow version should be very similar to that in sheep, slightly less similar to those in elephants and platypuses, and much less similar to those in snakes and lizards.
But not so. If you draw BovB’s family tree, it looks like you’ve entered a bizarre parallel universe where cows are more closely related to snakes than to elephants, and where one gecko is more closely related to horses than to other lizards.
This is because BovB isn’t neatly passed down from parent to offspring, as most pieces of animal DNA are. This jumping gene not only hops around genomes, but between them.
This type of “horizontal gene transfer” (HGT) is an everyday event for bacteria, which can quickly pick up important abilities from each other by swapping DNA. Such trades are supposedly much rarer among more complex living things, but every passing year brings new examples of HGT among animals. For example, in 2008, Cedric Feschotte (now at the University of Utah) discovered a group of sequences that have jumped between several mammals, an anole lizard, and a frog. He called them Space Invaders.
The Space Invaders belong to a group of jumping genes called DNA transposons. They jump around by cutting themselves out of their surrounding DNA, and pasting themselves in somewhere new. They’re also relatively rare—they make up just 2 to 3 percent of our genome. BovB belongs to a different class of jumping genes called retrotransposons. They move through a copy-and-paste system rather than a cut-and-paste one, so that every jump produces in a new copy of the gene. For that reason, they spread like wildfire.
BovB was first discovered in the genomes of cows and other cud-chewing mammals in the 1980s, and seemed to be a signature of that group. Then, in the 1990s, Dusan Kordis and Franc Gubensek detected an extremely similar version of BovB amid the genes of the horned viper. It looked like this piece of DNA had jumped between species. Now, with complete genomes of the cow and other animals at hand, Walsh has more fully mapped BovB’s voyage through the animal kingdom. [Continue reading...]
Paul Seabright author of The Company of Strangers: A Natural History of Economic Life, interviewed at The Browser.
You have turned to evolutionary biology and anthropology to help understand the development of economic institutions and behaviour. Why are they important in helping us get to grips with today’s complex and fast-moving world?
They are important because we are a species like any other and have this wonderful construction, which is the society we’ve built. It’s as wonderful, or more so even, as the extraordinary nests built by ants and termites or the incredible song and other behavioural patterns of birds. I’ve always thought that if we take animals seriously as producing behaviour and not just bodies, then we should do the same for ourselves. We should see our behaviour as coming out of the constraints of our environment and the adaptations that have developed in the history of our species.
It used to be fashionable to think that genes, and indeed the process of natural selection, affected our bodies but not our minds. We’ve come to realise that that’s untrue and that our minds are profoundly shaped by natural selection – even if the environment we now live in is massively different from the one in which most of that evolution took place. So you can learn a lot from the fact that our minds are not just any old general purpose computer. They are actually shaped by evolution, though we have to remember that the circumstances in which we evolved are startlingly different from the circumstances in which we now have to navigate.
The world has got a lot more complex in the last 100 years or so and human minds have to process ever larger amounts of information. Are they evolving fast enough to deal with it?
No, in some ways they aren’t. A very good example is the way in which we process a lot more digital information now than we used to – we read a lot more text. People sometimes say we are completely overwhelmed with incoming information in the modern world, and that’s true. But in a certain sense our hunter-gatherer ancestors were also overwhelmed with incoming information – they would be sitting around their fires with their senses very carefully tuned for predators, for example. They would also take in information about their environment with a tremendously high bandwidth, in terms of how they judged their fellow human beings as being hostile or friendly, reliable or untrustworthy. Natural selection produced a number of mechanisms that helped them deal with that bandwidth. For example, we know we have these abilities to size up people’s faces with extraordinary speed and sophistication – we can tell just from the location of the white of somebody’s eyes who they are looking at, and whether their relationship with people around them is dominant or submissive, aggressive or defensive, competitive or collaborative.
In the modern world we can still do all that sort of thing rather quickly, but a much larger part of the information comes in the form of text, some of which we deal with using a part of the brain called “working memory”, which has a much lower bandwidth. For example, the standard idea is that you can hold about seven to nine items of information in working memory at one time. That’s enough to remember somebody’s telephone number, but if you try to remember somebody’s telephone number and try to do something else that requires textual manipulation at the same time, you are very quickly overwhelmed. That’s a good example of how natural selection shaped the brain for the kind of tasks that we needed to do in the Pleistocene but didn’t – for obvious reasons – foresee the kinds of tasks we would have to do in the 21st century. [Continue reading...]
Michael Shermer writes: It is the oldest and most universally recognized moral principle, codified more than 2,000 years ago by the Jewish sage Hillel the Elder: “Whatsoever thou wouldst that men should not do to thee, do not do that to them. This is the whole Law. The rest is only explanation.” The explanation of morality was the subject of intense theological and philosophical disputation well before Hillel, of course, and has been ever since. Lately scientists have begun weighing in with naturalistic views of the matter, and now their cause has been joined by Paul J. Zak with The Moral Molecule and Christopher Boehm with Moral Origins.
Mr. Zak, an economist and pioneer in the new science of neuroeconomics, has built his reputation on research that has identified the hormone oxytocin as a biological proxy for trust. As he documents, countries whose citizens trust one another gain economically, enjoying a higher gross domestic product, on average, than countries where lower levels of trust exist. Mr. Zak explains that trust is built through mutually beneficial exchanges that result in higher levels of oxytocin.
How does he know this? By studying blood samples taken from participants in economic-exchange games administered by researchers as well as from people in real-world encounters. “The Moral Molecule” is an engaging popular account of Mr. Zak’s decade of intense research into how oxytocin evolved for one purpose—pair bonding and attachment in social mammals—but had the bonus effect of cementing a sense of trust among strangers.
The problem to be solved here is why strangers would be nice to one another. Evolutionary “selfish gene” theory accounts for why we would be nice to our kin—they share our genes, so being altruistic and moral has an evolutionary payoff in our genes being indirectly propagated into future generations. The theory of kin selection explains how this works, and the theory of reciprocal altruism—I’ll scratch your back if you’ll scratch mine—goes a long way toward explaining why unrelated people in a social group would be kind to one another: My generosity to you today, when my fortunes are sound, may pay off down the road if life is good to you and my luck has run out. What Mr. Zak has so brilliantly done is to identify the precise biological pathways through which this behavior system evolved and operates today. [Continue reading...]
Pat Shipman writes: We all know the adage that dogs are man’s best friend. And we’ve all heard heartwarming stories about dogs who save their owners—waking them during a fire or summoning help after an accident. Anyone who has ever loved a dog knows the amazing, almost inexpressible warmth of a dog’s companionship and devotion. But it just might be that dogs have done much, much more than that for humankind. They may have saved not only individuals but also our whole species, by “domesticating” us while we domesticated them.
One of the classic conundrums in paleoanthropology is why Neandertals went extinct while modern humans survived in the same habitat at the same time. (The phrase “modern humans,” in this context, refers to humans who were anatomically—if not behaviorally—indistinguishable from ourselves.) The two species overlapped in Europe and the Middle East between 45,000 and 35,000 years ago; at the end of that period, Neandertals were in steep decline and modern humans were thriving. What happened?
A stunning study that illuminates this decisive period was recently published in Science by Paul Mellars and Jennifer French of Cambridge University. They argue, based on a meta-analysis of 164 archaeological sites that date to the period when modern humans and Neandertals overlapped in the Dordogne region of southwest France, that the modern-human population grew so rapidly that it overwhelmed Neandertals with its sheer numbers.
Because not all the archaeological sites in the study contained clearly identifiable remains of modern humans or Neandertals, Mellars and French made a common assumption: that sites containing stone tools of the Mousterian tradition had been created by Neandertals, and those containing more sophisticated and generally later stone tools of the Upper Paleolithic were made by modern humans. This link between tool and toolmaker is well supported by sites that do contain hominin remains, but there is nothing inherent in a stone tool that tells you who made it—not even if you find a skeleton right next to it. Still, stone tools are one of the best available indicators of which species—modern human or Neandertal—inhabited a particular location.
Mellars and French compared the number and sizes of Neandertal and modern-human archaeological sites, as well as the density of tools and the weight per square meter of prey animals, represented by fossils, in those sites. They standardized their results for 1,000-year periods to compensate for the varying amounts of time that the different locations had been occupied. In every respect, modern humans surpassed Neandertals. In fact, the greater success of modern humans was so clear that, according to Mellars and French’s calculations, the human population increased tenfold over the 10,000-year overlap period. Modern humans thrived and Neandertals did not—even though Neandertals had lived in the European habitat for about 250,000 years before modern humans “invaded.” Why weren’t Neandertals better adapted to their environment than the newcomers?
There is no shortage of hypotheses. Some favor climate change, others a modern-human advantage derived from the use of more advanced hunting weapons or greater social cohesion. Now, several important and disparate studies are coming together to suggest another answer, or at least another good hypothesis: The dominance of modern humans could have been in part a consequence of domesticating dogs—possibly combined with a small, but key, change in human anatomy that made people better able to communicate with dogs. [Continue reading...]
Maria Konnikova writes: Last week, Facebook made its largest ever acquisition: Instagram, the popular photo-sharing service that lets you snap, filter and send with the click of a button. While the fit seems to make sense – a major reason to use Facebook is to share photos; the more photos you share the more time you spend on the site; the more time you spend, the happier the advertisers – the $1bn price tag raised many an eyebrow.
But should the price come as a surprise or is the purchase perhaps a visionary move? In making its offer for Instagram, Facebook had, I think, recognised the ever-growing importance of one little impulse that is awfully hard to resist: the urge to share.
That irresistible impulse to post, to tweet, to “like” has evolutionary roots that far precede the advent of social media. Consider something that’s known as the “communal sharing” norm. In an environment of scarce resources (ie, the one that prevailed for most of our history), every existing resource has to be shared with others. In this environment, what I find out isn’t my exclusive prerogative – it’s actually common property, in case it can be beneficial to someone else. There’s a bear in that cave; these berries may kill you; I found a stream of water in that direction. All important information to pass on and the quicker the better. After all, the bear may wake up or the berries may end up in someone’s mouth before we’ve had a chance to share our wisdom.
The facts may have changed, but the immediacy seems just as real now. It’s hard to shake off the feeling that people are somehow missing out or worse off if we don’t communicate what we’ve seen – and communicate it at once. Is it really so far from: “There’s a bear in the cave” to: “Look at that adorable bear playing with the berries in that YouTube video”? We don’t just passively take in information. We want actively to pass it on to others. We share emotions; we share thoughts; we share opinions; we share objects. We share because we’re happy, angry, perplexed, upset. Or experiencing any strong emotion.
Max Rivlin-Nadler writes: You walk into an elevator and push the button for your desired floor. The button lights up. The elevator stops at the next floor and another person enters. He or she pushes the same button that’s already lit up.
According to Dario Maestripieri’s new book, “Games Primates Play,” that elevator ride represents a game of dominance — similar to those exhibited by other primates. The University of Chicago professor argues that our social relationships have analogs in nature, especially within groups of primates. While we may not go up and grab our supervisor’s genitals as a sign of respect, we engage in similar acts that help us figure out where we fit in groups.
By exploring our social lives through the lens of an evolutionary biologist, Maestripieri breaks down the most routine of social interactions into deeply embedded behaviors from our genetic forebears. Just like humans, other primates grapple with questions of dominance, reciprocation, nepotism and fidelity. He demonstrates how his own life, the lives of celebrities, and corporate success strategies all derive from a single, primal need to find our place in a group.
Salon spoke with Maestripieri about the primal instincts we exhibit in our emails, whether altruism exists, how nepotism is natural, and why it matters to study our everyday nature. [Continue reading...]
Alexander Star writes: Why do horses snort? Sometimes, at the approach of a stranger or the appearance of a plane high above the pasture, a horse will widen its eyes, flare its nostrils and send a stuttering column of air out into the world. On other occasions, horses have been known to snort for no reason besides their own boredom. By suddenly creating a sound, the slack-minded horse elicits an automatic “startle response” — flooding its brain with chemicals, delivering a jolt of excitement and relieving, at least for a moment, the monotony of a long day in an empty field. The horse has in effect fooled its own nervous system — and benefited from the self-deceit.
If horses can alter their own brain chemistries at will (and have good reasons to do so), what about human beings? In “On Deep History and the Brain,” Daniel Lord Smail suggests that human history can be understood as a long, unbroken sequence of snorts and sighs and other self-modifications of our mental states. We want to alter our own moods and feelings, and the rise of man from hunter-gatherer and farmer to office worker and video-game adept is the story of the ever proliferating devices — from coffee and tobacco to religious rites and romance novels — we’ve acquired to do so. Humans, Smail writes, have invented “a dizzying array of practices that stimulate the production and circulation of our own chemical messengers,” and those devices have become more plentiful with time. We make our own history, albeit with neurotransmitters not of our choosing.
Historians by and large take biology and the deep past for granted: natural selection endowed our ancestors with their impressive bodies and brains, and then got out of the way. These days, it’s chiefly nonhistorians like Jared Diamond and Tim Flannery who seek to trace the long arc of the species and write macrohistory in a scientific key. Smail, who teaches medieval history at Harvard, would like his peers to join their company. If historians have become accustomed to studying midwives and peasants, the marginal and often illiterate members of recent societies, why shouldn’t they extend their curiosity to the most peripheral human subjects of all — the prehistoric? Even today, Smail laments, the curriculum is shaped by the prejudice that history began only when our ancestors started to write or to farm or to think of themselves as actors in a grand pageant of historical change. The presumption is curiously convenient. In the schema of “sacred history,” history began with the expulsion of Adam and Eve from the Garden of Eden — that is, in Asia, a few thousand years before Christ. In the modern schema, history begins in much the same place, at much the same time. “The sacred was deftly translated into a secular key,” Smail writes, as “the Garden of Eden became the irrigated fields of Mesopotamia and the creation of man was reconfigured as the rise of civilization.”
Taking Paleolithic man seriously, Smail argues, requires us to understand that history and biology always shape each other — there is no ascent from the tyranny of brute instinct to the freedoms of civilization. Some evolutionary theorists stress that cultural innovation allows human beings to overcome the blind stumblings of natural selection: we deliberately solve a problem and pass on that solution to our descendants, who improve on it in turn. Smail takes a different tack. The imperfect copying of past behavior and small, often unconscious preferences can push a society in a new direction, even without anyone aiming toward a particular goal. It’s possible, for instance, that early men decided to make sharper spear points with the intent of drawing more blood from their prey; Smail would rather suppose that these spear points were created by accident, and then spread because the hunters who used them proved to be better hunters, even if they didn’t know why. Cultural evolution can be rapid and it can help human beings adapt to their environment, but it needn’t be intended or progressive. [Continue reading...]
Katherine Stewart writes about the latest chapter in the campaign to keep Americans stupid — which is to say, efforts to guard fragile minds from the truth about evolution — and notes that there are “six bills aimed at undermining the teaching of evolution before state legislatures this year: two each in New Hampshire and Missouri, one each in Indiana and Oklahoma. And it’s only February.”
Most of these bills aren’t likely to get anywhere. The Indiana bill, which specifically proposes the teaching of “creation science”, so obviously falls foul of the supreme court’s 1987 ruling that it’s hard to imagine it getting out of committee. The same could be said for the Missouri bill, which calls for the “equal treatment” of “biological evolution and biological intelligent design”.
Still, it’s worth asking: why is this happening now? Well, in part, it’s just that anti-evolution bills are an indicator of the theological temperature in state houses, and there is no question that the temperature has been rising. New Hampshire, Indiana, Oklahoma, and Missouri turned deeper shades of red in the 2010 elections, as did the US Congress.
But there are a couple of new twists that make this same-old story more interesting than usual. One has to do with the temperature in a less metaphorical sense. The Oklahoma bill isn’t properly speaking just an “anti-evolution” bill; it is just as opposed to the “theory” of “global warming”. A bill pending in Tennessee likewise targets “global warming” alongside “biological evolution”. These and other bills aim their rhetoric at “scientific controversies” in plural, and one of the New Hampshire bills does not even bother to specify which controversies it has in mind.
The convergence here is, to some degree, cultural. It just so happens that the people who don’t like evolution are often the same ones who don’t want to hear about climate change. It is also the case that the rhetoric of the two struggles is remarkably similar – everything is a “theory”, and we should “teach the controversy”. But we also cannot overlook the fact is that there is a lot more money at stake in the climate science debate than in the evolution wars. Match those resources with the passions aroused by evolution, and we may have a new force to be reckoned with in the classroom.
Christopher Ryan challenges Steven Pinker’s dubious claim that we live in the most peaceful of times. Pinker bases his argument on a comparison of male deaths due to war using what he treats as modern tribal correlates of our hunter-gatherer ancestors.
The seven cultures listed on Pinker’s chart are the Jivaro, two branches of Yanomami, the Mae Enga, Dugum Dani, Murngin, Huli, and Gebusi.
Are these societies actually representative of our hunter-gatherer ancestors?
Are they even hunter-gatherers at all?
Only the Murngin even approach being an immediate-return hunter-gatherer society like our prehistoric ancestors, and they had been living with missionaries, guns, and aluminum powerboats for decades by 1975, when the data Pinker cites were collected.
None of the other societies cited by Pinker are even arguably immediate-return hunter-gatherers like our ancestors. They cultivate yams, bananas, or sugarcane in village gardens while raising domesticated pigs, llamas, or chickens. This is crucial, because societies are far more likely to wage war when they have things worth fighting over (pigs, gardens, settled villages), but tend to be far less conflictive when living as nomadic hunter-gatherers, with little to plunder or defend. Any first-year anthropology student knows this. Presumably, so does Pinker.
Beyond the fact that these societies are not remotely representative of our nomadic hunter-gatherer ancestors, there are more problems with the data Pinker cites. Among the Yanomami, true levels of warfare are subject to passionate debate among anthropologists. The Murngin are not typical even of Australian native cultures, representing a bloody exception to the typical pattern of little to no intergroup conflict. Nor does Pinker get the Gebusi right. Bruce Knauft, the anthropologist whose research is cited on this chart, reports that warfare is “rare” among the Gebusi, writing, “Disputes over territory or resources are extremely infrequent and tend to be easily resolved.”
To make matters even worse, Pinker juxtaposes these bogus “hunter-gatherer” mortality rates with a tiny bar showing the relatively few “war-related deaths of males in twentieth-century United States and Europe.” This is a false comparison because the twentieth century gave birth to “total war” between nations, in which civilians were targeted (Dresden, Hiroshima, Nagasaki… ), so counting only male military deaths requires ignoring all the millions of civilians victimized by war.