Superorganisms and Group Selection

Unicolonial ants pose challenge to "selfish gene" theory.

Unicolonial ants, such as these Argentine ants (Linepithema humile), are genetically unrelated but will cooperate to defeat a much larger adversary.
Source: Alex Wild / Live Science
It has been a mainstay of evolutionary theory since the 1970s. Natural selection acts purely on the level of the individual and any cooperation observed between organisms merely hides a selfish genetic motive. There have been two pioneering theories to explain cooperation in the natural world given this framework: the first was William Hamilton's (1964) theory of kin selection and the second was Robert Trivers' (1971) theory of reciprocal altruism.

However, both of these scenarios break down where it comes to unicolonial ants. In a new paper in the journal Trends in Ecology and Evolution (subscription required) Heikki Helantera, of the University of Sussex, and colleagues at Rice University have investigated how previous theories to explain cooperation don't apply for these unique supercolonies.

Unicolonial ants carry polydomy [multiple nests in a supercolony that all individuals rotate through] and polygyny [multiple queens in one nest] to extremes. Colonies are huge, each being a network of hundreds or thousands of nests, each with multiple queens. There is no worker aggression, and there is free movement among nests on a vast scale. The energy that might have been put into fighting and territoriality flows into the common good, more ants.

Such a concept, a form of genuine anarchism in the animal world, was thought to be impossible given existing theory. These ants live in colonies where relatives exist but, with so much migration throughout a network stretching thousands of kilometers, each ant worker is mostly surrounded by total strangers that share none of their genes. Only one other species has ever been known to organize themselves in such a fashion (and if you're reading these words right now you know who you are).

To understand how unicolonial ants have come to be the way they are, we must first understand what they're not. Kin selection has proposed that cooperation will emerge in groups that are made up of close relatives. Hamilton's rule, beautiful in its simplicity, proposed that cooperation occurs when the cost to the actor (C) is less than then the benefit to the recipient (B) multiplied by the genetic relatedness between the two (r). This equation is written out simply as rB > C.


Lion siblings often cooperate as teams and benefit through kin selection.
Source: Scotch Macaskill / Wildlife Pictures.com
To put this into context: an alpha male lion and his brother share half of their genes, so have a genetic relatedness of 0.5. Suppose this brother recognizes that the alpha male is getting old and could easily be taken down. If so, the brother could potentially have eight additional cubs (just to pull out an arbitrary number). But, instead, that brother decides to help the alpha male to maintain his position in the pride and, as a result, the alpha ends up having the eight additional cubs himself while the brother only has five. The brother has lost out on 3 potential cubs. But, even so, because he assisted his brother he has still maximized his overall reproductive success from a genetic point of view: (0.5) x 8 = 4 > 3. He could have attempted to usurp his brother and, perhaps, had the eight cubs himself but he wouldn't have been in any better of a position as far as his genes were concerned.

Reciprocal altruism follows this same basic idea, but proposes a mechanism that could work for individuals that are unrelated. In this scenario, cooperation occurs when the cost to the actor (C) is less than the benefit to the recipient (B) multiplied by the likelihood that the cooperation will be returned (w) or wB > C. This has been demonstrated among vampire bats who regurgitate blood into a stranger's mouth if they weren't able to feed that night. Previous experience has shown the actor that they're likely to get repaid if they ever go hungry one night themselves. This theory requires that individuals be part of a single group, with low levels of immigration and emigration, so that group members will be likely to encounter each other on a regular basis.

Previously, it was argued that all ants followed an extreme form of kin selection. Because of their unique process of reproduction females develop from fertilized eggs and have paired chromosomes (that is, one from each parent). However, males develop from unfertilized eggs and only have a single chromosome from their mother. As a result, female workers share up to 75 percent of their genes with sisters but only 50 percent with their mother (or their own offspring, if they were to reproduce). Worker ants therefore have greater genetic success by not reproducing but, instead, helping to raise and protect their legion of closely related sisters.


Ant reproduction gives rise to genetic sisterhood.
Source: Unattributed
This explanation has been somewhat clouded given more recent evidence that queens engage in polyandry (mating with multiple males). A queen will frequently mate with up to five different males and store their combined sperm, around 100 million of them, in a special compartment called the spermatheca. By releasing a single sperm at a time the queen can control the number of eggs she lays. However, because there are multiple fathers, the genetic relationship between the female worker ants is reduced. Female workers may therefore only be related by 25 percent with the females they're helping to raise. Why would female workers continue to be non-reproductive and help rear distant relatives when they could have twice the reproductive success by having their own offspring? While there are strategies female workers employ to maximize their own reproductive success (like preferrentially rearing eggs that they are more closely related to or, in some rare cases, reproducing themselves) it still remains puzzling why ants have been so successful given this seeming contradiction.

If you add to this the realities of multiple queens in a single nest (polygyny) and supercolonies that are composed of thousands of such nests (polydomy), the problem becomes insurmountable. If worker ants share zero percent of their genes with those they're cooperating with, as is the case in these unicolonies, then why cooperate? What do they have to gain?

This is the problem that Helantera and colleagues are seeking to understand in their latest paper. While the authors emphasize a range of possible explanations, I want to focus on just one that has been generating a great deal of interest in the last few years: group selection.

The extreme cooperation of unicolonial ants has been suggested to be an example of selection occurring on levels higher than the individual, such as the superorganism, group or even population.

Group selection is the idea that, under certain circumstances, genes will be selected for because they benefit the overall success of the group rather then simply the individual. While it is usually assumed that these populations will have a high level of relatedness (making the promotion of the group an extended form of kin selection) the authors suggest a scenario in which group selection could apply even among unrelated group members.


Giant ants terrorize humanity in Them!.
Source: Warner Bros.
This is a possibility I like to call Ronald Reagan's Alien Invasion Hypothesis. In a speech before the United Nations on Sept. 21, 1987 Reagan stated that:

In our obsession with antagonisms of the moment, we often forget how much unites all the members of humanity. Perhaps we need some outside, universal threat to make us recognize this common bond. I occasionally think how quickly our differences worldwide would vanish if we were facing an alien threat from outside this world.

So under this possibility a common threat to all colony members would outweigh the low level of genetic similarity because, unless everyone pulls together, the entire group is in jeopardy. If one colony was competing with a rival colony then selection for individual selfishness could drive the population to extinction while selection for cooperation would allow the colony to thrive.

Under this view, extant unicolonial populations are the ones that have not yet succumbed to selfishness. Relatedness and mutual policing select against selfishness in non-unicolonial populations, but stop applying when relatedness decreases to zero. . . [However], constraints arising from the natural history of the species or pleiotropic effects of selfish genes, might prevent selfish genotypes from arising even under zero relatedness.

This cooperation could then continue long after the initial threat was gone under the force of phylogenetic inertia. Perhaps, in the future, selection would cause the unicolony to break into smaller, more genetically similar colonies once the impetus for group selection no longer exists? Or perhaps the benefits of cooperating with strangers simply outweighs the costs of competition and natural selection has produced a genuinely altruistic society?


Unicolonial cooperation has inspired activist art such as this print from the Beehive Collective.
Source: Beehive Collective
At the current time there are 31 known unicolonial ant populations around the globe. This is a small minority given the more than 12,000 described species. However, given that research on unicolonial ants is so new, there is still a great deal of research that needs to take place concerning this unique experiment of the natural world. At the very least, unicolonies provide us with a source of inspiration and the ability to marvel at the amazing beauty and diversity of the natural world. With the knowledge that stable supercolonies composed of strangers continue to thrive in nature, perhaps there's something we could learn from those creatures that first invented this approach.

References:

Hamilton, W.D. (1964). The genetical evolution of social behaviour I and II. — Journal of Theoretical Biology 7: 1-16 and 17-52

Trivers, R.L. (1971). The evolution of reciprocal altruism. Quarterly Review of Biology. 46: 35-57.

Helantera, H., Strassman, J.E., Carrillo, J., Queller, D.C. (2009). Unicolonial ants: where do they come from, what are they and where are they going? Trends in Ecology and Evolution. doi:10.1016/j.tree.s009.01.013

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Darwin's Controversy of the Corals

The Reef Tank is currently hosting my new post that tells the story of one of the largest controversies in the history of science. It involves Charles Darwin, a son defending his father's honor and the threat of nuclear annihilation. Intrigued? Go over and check it out, as well as some great posts by other fellow science bloggers. Here is a quick taste:

It took the threat of nuclear annihilation between the two greatest powers of the 20th century to solve one of the most profound scientific controversies of the 1800s. In 1952 Dr. Harry Ladd, a researcher for the US Geological Survey, convinced the US War Department to drill holes deep into the Bikini and Eniwetok Atolls just prior to their obliteration by hydrogen bombs. The reason for the drilling had little to do with the nuclear tests as part of Operation Crossroads, but was simply to conduct an experiment based on the hypothesis of coral reef formation first proposed by Charles Darwin in 1837.

Read the rest here.

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Bonobos in the Garden of Eden

Our primate cousins could turn the question of human origins upside down.

Could the bonobo homeland also be the origin of our common ancestor?
Image: Cyril Ruoso / Time

In an interview with Dan Harris on Nightline, bonobo researcher Dr. Bila-Isia Inogwabini recently suggested that humans may have first evolved in the Western area of the Democratic Republic of Congo rather than in East Africa where most of the fossil evidence has been discovered.

“I really strongly feel that people may have evolved from this region,” he said. "It’s a big claim, yes, I understand, but I really think it is worth it to put it on the table."

Genetic evidence suggests that humans, bonobos and chimpanzees shared a common ancestor between 4.6 to 6.2 million years ago (mya). One population eventually became the genus Homo while the other, Pan, diverged again about 1.3 mya to become modern day bonobos and chimpanzees. What remains unknown is where and why this Pan-Homo split occurred that sent our species along such a different evolutionary path.

The vast majority of hominin fossils have been found in eastern Africa, in what is modern day Ethiopia, Kenya and Tanzania. The most reasonable assumption has long been that it was in East Africa, near the Rift Valley, where the Pan-Homo division took place. However, the earliest hominin fossil find to date, Sahelanthropus tchadensis, is between 6-7 mya and was found in in the central African country of Chad (about 2,500 km away). S. tchadensis was much more ape-like than later Australopithecines and is thought to have coexisted alongside our common ancestor with chimpanzees and bonobos.

This early Chad find is important considering that the fossil record is so sparse between 12 mya and 4 mya (the crucial period as far as we're concerned). The only representatives of this vast period after S. tchadensis was Orrorin tugenensis (6 mya from Kenya) an ape species that may have been partially bipedal, Ardipithecus ramidus kadabba (5.5 mya from Ethiopia) and Ardipithecus ramidus ramidus (4.4 mya also from Ethiopia). All of these species were much more apelike than the Australopithecines, which first appear in the fossil record 4.15 mya in Kenya and 4.1 mya in Ethiopia. An excellent timeline at hominin.net helps put these dates and the location of the finds into context.


Fossil map showing many of the hominin fossil discoveries throughout Africa.
Image: National Geographic
While Ethiopia or Kenya would seem to be the most likely candidates for the split between Homo and Pan, the fact that the earliest known hominin has been found in Chad has raised some questions about this. Writing in the journal Nature about how the discovery of S. tchadensis changes our understanding of early human origins, Brunet. et al state:

This suggests that an exclusively East African origin of the hominid clade is unlikely to be correct. It will never be possible to know precisely where or when the first hominid species originated, but we do know that hominids had dispersed throughout the Sahel and East Africa by 6 Myr.

Furthermore, Australopithecus bahrelghazali (about 3.6 mya) was also discovered in Chad, suggesting that there is a great deal of material still to be discovered in this region. Later hominin fossils have also been discovered in South Africa (such as Australopithecus africanus and Paranthropus robustus). This means that the distribution of hominins extends all the way from Chad to East Africa to South Africa. Interestingly, the nearest central point between all these locations is the Democratic Republic of Congo.

This brings us to bonobos, the species that Dr. Inogwabini has studied for many years. Bonobos are found only in the DR Congo and had their last common ancestor with chimpanzees about 1.3 mya. Emory University primatologist Frans de Waal has argued that bonobos haven't changed much in the 4-6 million years since humans, chimpanzees and bonobos shared a common ancestor.

"The bonobo may more closely resemble the common ancestor of all three modern species," De Waal says. "It's an important issue that's yet to be resolved."

Remarkably, many of these traits are shared by only one other extant species: humans. Regular bipedalism, face-to-face mating (requiring a more ventral orientation of the vagina), reduced limb and body proportions, reduced canines, greater breadth of diet, larger group sizes and reduced competition within groups; all of these traits are shared more closely with humans than chimpanzees. Anatomically, bonobos show more similarities than chimpanzees to the early hominin Ardipithecus (5.5 mya). This could mean that bonobos are closer to the ancestral population and that chimpanzees diverged in order to adapt to different environmental pressures. But it could also be that early humans and bonobos experienced convergent evolution based on similar environments. At this point the evidence to address these questions is thin.


Bonobos are the only primate, other than humans, that regularly walk upright.
Image: Unattributed
Unfortunately, fossils are unlikely to help. Rain forest soils are notoriously bad for fossilization. The bones will decay long before minerals can replace the organic material. Even in ideal conditions (such as arid or anoxic environments) fossilization is extremely rare. So there is a certain amount of "environmental bias" in the fossil record. Unless an organism had a large enough range to be living in the right location for fossilization to occur, there will be no record that they ever existed. This could mean that the hominin fossils we do have were from individuals after they had migrated to the far edge of their original range and that the really exciting evolutionary events occurred in Central Africa. If this is the case, then the reason we have so many fossils from East Africa isn't because that was the cradle of humanity, it's just because the conditions were right for fossilization. Unfortunately, without evidence to test this hypothesis it remains in the realm of mere conjecture.

One piece of evidence that makes me think bonobos and humans might have shared more than just a similar environment has to do with a region of DNA promoting the release of oxytocin. At the AVPR1A gene both humans and bonobos (but not chimpanzees) share a repetitive microsatellite locus that Elizabeth Hammock and Larry Young have shown to be important for cooperation, empathy and social bonding. It is far more parsimonious that chimpanzees lost this repetitive microsatellite than for both humans and bonobos to independently develop the same mutation.

So if I had to make my best guess, I would put my money on the Pan-Homo split occuring in the mosaic environments of Central Africa near DR Congo. I would also predict that this common ancestor would appear more bonobo-like than chimpanzee-like. We may never know the real answer. But, considering the exciting "hobbit" fossils discovered on the island of Flores, Indonesia, it may be possible for fossilization to occur even in the rain forest if conditions are just right. At this moment, somewhere in a cave near Lac Tumba in the Democratic Republic of Congo, our common ancestor with bonobos and chimpanzees may be lying in wait for the next intrepid explorer to unearth. If so it would be the anthropological find of the century. Our long search to understand human origins would finally be at an end.

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Turkey Censors Darwin

As reported in the latest edition of Nature, government officials in Turkey have just censored the leading science periodical, Bilim ve Teknik (Science and Technology) for placing Charles Darwin on the cover. The editor was subsequently fired by the government agency that supports the magazine and many Turkish scientists are justifiably outraged.

In Turkey, as in many countries, the civil service is expected to mirror the ruling party's ideology. So, although they are keen funders of research, most senior government officials, in common with most of the population, do not believe in evolution by natural selection. The education minister Hüseyin Çelik, for example, has proclaimed his belief in intelligent design.

This is unfortunate considering that Muslim scholars and scientists were at the forefront of the scientific revolution long before Europeans got their act together. It's only been in the last twenty or thirty years that there has even been a crackdown on evolutionary ideas in Turkey. According to the History of Science Society:

In the 1970s, political Islam started to gain strength in Turkey as well as the rest of the Muslim world. Evolution became a minor culture war item, as a way for Islamists to demonstrate opposition to secular life without taking the risk of naming official secularism as a target. But creationism came into its own only in the mid 1980s, when in the aftermath of a short period of military dictatorship, religious conservatives gained control of the Turkish Ministry of Education. These conservative Muslims thought evolutionary ideas were morally corrosive, yet they found themselves in an environment where science commanded significant cognitive authority. So they needed a way to suggest that evolution was a fraudulent, scientifically dubious idea. They found the resources they needed in American “scientific creationism,” and invoked Christian creationists in a curious mirror image of the way Turkish secularists regularly relied on Western scientific authorities.

So there you have it. In an effort to reject Western secular ideas, fundamentalist Turks have embraced the Western fundamentalist rejection of science and reason. You wouldn't think that the very people that are most vocal about promoting war in the Middle East (isn't it curious how those most apt to honor the "prince of peace" are so ready to go to war) would also be the ones that conservative Muslims would be listening to for their approach on science and education. I guess that just shows that there is common ground between seemingly incompatible societies (though it doesn't offer us much hope at present).

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Contrary to All Reason

Catholics embrace the science of evolution, but reject its method.

Miraculously, a Darwin-shaped figure appears inside the Holy Church.
Image: The Onion
Last year the Church of England personally apologized to Darwin for misunderstanding natural selection. Now the Catholic Church is following suit. The Vatican is sponsoring a five-day conference on Darwin to mark the 150th anniversary of The Origin of Species. In a statement on the opening day Cardinal William Levada, head of the Vatican's Congregation for the Doctrine of Faith, said that Church doctrine does not conflict with evolution and that there is a "wide spectrum of room" to accept both.

According to the Associated Press:

"We believe that however creation has come about and evolved, ultimately God is the creator of all things," he said on the sidelines of the conference. But while the Vatican did not exclude any area of science, it did reject as "absurd" the atheist notion of biologist and author Richard Dawkins and others that evolution proves there is no God, he said. "Of course we think that's absurd and not at all proven," he said. "But other than that ... the Vatican has recognized that it doesn't stand in the way of scientific realities."

Of course, hearing the Catholic Church reject atheism is about as meaningful as listening to Newt Gingrich reject "European-style socialism" at CPAC. Both know what side their bread is buttered on. In 2002, according to former Church finance minister Edmund C. Szoka, the Catholic Church held at least $5 billion in assets and had seen their annual profits increase to $22 million. Now that we've entered a global recession they've even revived the old practice of granting indulgences to get yourself or a loved one out of purgatory. While official Church policy is that money is not required for a plenary indulgence, a donation could speed the process along. According to Rev. Chris Decker, pastor of St. Jude Catholic Church in Baton Rouge, LA:

When it comes to money, if people want to make an offering of thanksgiving, sometimes God moves us to action.

So Church officials aren't going to interupt the good thing they've got going, Darwin or no Darwin. But, because the scientific consensus is so strong, they're not able to appear serious any longer if they continue to deny that evolution is a scientific fact. This strategy to bring Darwin into the fold is merely an attempt to continue business as usual by attempting to rebrand natural selection as coming from divine origin. But I think the Catholic Church needs to better understand the definition of the word "absurd" if they're going to be flinging it about as they are.

ab·surd (adj.) utterly or obviously senseless, illogical, or untrue; contrary to all reason or common sense; laughably foolish or false.

Consider the following: Jesus Christ was sent by God (his father, but also himself) in order to die on the cross for the forgiveness of mankind. This was the ultimate sacrifice to atone for the original sin that accrued when Adam and Eve ate the apple in the Garden of Eden (an act that is also the explanation for why women experience pain in childbirth). This is official Church doctrine accepted from the divine authority of Saint Paul the Apostle in Romans 5:15-21.

However, since human evolution completely negates the story of Adam and Eve, that means there was no original sin. So, in other words, the Catholic Church's official view is now that a supernatural entity descended from the sky so that he could be brutally tortured as a way to forgive people for something that never happened in the first place. And this is somehow less absurd than the idea that people invented these stories to help explain phenomena they weren't able to figure out at the time?

I have no doubt that Catholics will eventually figure out a way to explain away the inconsistencies in their ramshackle worldview. 376 years ago Galileo Galilei was condemned by the Pope for daring to say that the Earth moved around the Sun. Psalm 93:1 states explicitly that the Earth "cannot be moved," and it was feared that any claim otherwise would shake Catholic faith in the divine authority of the Bible. Well, the Earth moves and the Pope still wears his red Prada slippers. Catholics managed to read around that quote and they'll do so again, no matter how absurd their justifications may be.

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The Bad Taste of Moral Turpitude

A new study reveals the oral origins of moral disgust

Protester in Iceland shows her disgust after US toxic assets infect global markets.
Image: Der Spiegel
The greed and avarice responsible for the current economic meltdown has resulted in a growing distaste for business as usual. As it turns out, evolution may explain just why this is. Speaking about his reaction to the economic crisis, Jeremy Warner, writing in the British newspaper The Independent, states that:

The spectacle of secretive deal-making on luxury yachts and at five-star hotels amid the Mediterranean playgrounds of the world's super rich leaves a bad taste in the mouth and is plainly offensive to the thousands of ordinary lives likely to be affected by it.

This kind of physical expression of distaste for immoral behavior is commonplace in our language. A used car salesman’s offer seems “fishy” or the crimes of a corporate banker are condemned as “wretched” behavior. Even the word "turpitude" is based on the latin root turpis for something foul. But why would something as abstract as morality be associated with these physical expressions of digust?

Now, a study by psychologist Hanah Chapman and colleagues in the latest edition of the journal Science (subscription required), has sought to understand this connection and its evolutionary implications. In a series of careful trials, carried out at the University of Toronto, Chapman recorded facial data while participants were engaged in three separate experimental conditions to simulate different forms of disgust: oral, visual and moral.

In the first set of experiments, the researchers focused on the levator labii muscle region of the face, the muscle group responsible for raising the upper lip and wrinkling the nose. These facial muscles were thought to be the most important group for the expression of disgust. By using a technique known as electromyography (EMG), the activation of the muscle cells in this region could be precisely recorded. EMG data were then recorded from participants while they drank small samples of unpleasant-tasting bitter, salty and sour liquids. Then, by comparing the muscle response of participants while drinking the foul liquids to that of something sweet or neutral (such as water), the researchers hoped to demonstrate the levator labii region as the muscles responsible for the expression of oral disgust.

Confirming their predictions, the unpleasant drinks caused significantly more activity from the levator labii than either the sweet drink or the water produced. With their baseline measurements established, Chapman and her team could then move on to determine if more abstract feelings of disgust tapped into the same brain network as the disgusting tastes did.


Foul tasting liquids cause levator labii muscles to evoke expression of disgust.
Image: Chapman et al.

The researchers then recorded EMG facial data while showing a series of disgusting photographs such as feces, serious injuries or crawling insects to elicit an expression of visual disgust in the participants. They also showed sad and neutral photographs to act as controls in the same way that the sweet liquid and drinking water did in the previous test. Once again, only the disgusting photographs resulted in a significant activation of the levator labii muscles and the characteristic appearance of disgust in the participant. Now that the same group of muscles were shown to be activated in two separate forms of disgust, the researchers moved on to their final goal: moral disgust.

Having determined that both the primitive distaste response and more complex forms of disgust evoke levator labii region activity that is proportional to the degree of disgust or distaste experienced, we next examined whether the same pattern of results would hold for moral transgressions. Given that fairness is a cornerstone of human morality and sociality, we examined the facial motor activity associated with violations of the norm of fairness.

The researchers used a simulation known as the Ultimatum Game to model unfairness in social interactions. In this game, two players split $10: The first player, the proposer, makes an offer suggesting how the money should be split, which the second player, the responder, can accept or reject. If the responder accepts the offer, the money is split as proposed, but if they reject the offer then neither player receives anything. Each participant played 20 rounds of the Ultimatum Game in the role of responder while EMG data recorded their facial movements. The offers ranged from “fair” (an even $5:$5 split) to very “unfair” (proposing a $9:$1 split). The EMG data was then used to interpret the varying levels of unfairness that participants experienced as part of the game.

What the researchers concluded was that, when offers reached very unfair levels (such as an $8:$2 or $9:$1 split) the levator labii muscles activated revealing the players feeling of disgust at being cheated. Fair offers or offers that were in the players favor did not evoke this response. These EMG responses fit with the self-report that participants felt about the level of unfairness. During times where they felt cheated, they were disgusted by the other player’s behavior and their face responded accordingly. As the authors summarized their findings:

When participants received unfair offers, they judged their experience as most similar to tasting or smelling something bad. . . even though the “bad taste” left by immorality is abstract rather than literal.

French poster condemning the economic crimes of the rich. No translation necessary.
Image: Snup Paris.com

What these findings suggest is that reactions based on moral disgust influence decision-making in the same way that oral disgust would keep you from eating something noxious. This was certainly the case in the Ultimatum Game as the more disgusted the responder was by an unfair offer the less likely they were to accept it. It would seem that our economic decisions are not based purely on logic, but also on a physiological response based on our innate reaction to immoral behavior. As principal investigator Adam Anderson told United Press International:

These results shed new light on the origins of morality, suggesting that not only do complex thoughts guide our moral compass, but also more primitive instincts related to avoiding potential toxins. . . Surprisingly, our sophisticated moral sense of what is right and wrong may develop from a newborn's innate preference for what tastes good and bad, what is potentially nutritious versus poisonous.

Perhaps what’s most intriguing about this study is the implication that moral disgust “hitched a ride” on the more primitive reaction to poisonous or spoiled food. This process, known as exaptation, is where a trait or behavior that was adapted for one function is later co-opted and used for something entirely different (such as bird feathers adapted for use in thermoregulation and only later being useful for flight). In this case it would seem that our evolved neurological template for moral behavior tapped into the previously existing neural pathway for oral disgust. In this way, a physical aversion to immorality could have served as a check upon anti-social behavior in our ancestors and helped to reduce its prevalence in the social group.

Morality has long been thought to be a learned behavior and that if evolution were true it would mean that we are condemned to live in an immoral universe. The current economic crisis would seem to suggest that humans are indeed rotten to the core and in need of moral salvation. However, what this study demonstrates is that our intuitive sense of moral crimes are the direct result of our evolutionary history. As we continue to rinse our mouths of the policies that led to our current crisis we should keep in mind that, while trickery and deceit are a permanent part of our character, evolution has provided us with the very skills we need to create the kind of society that doesn't leave us reeling with a bitter aftertaste.

Reference:

H. A. Chapman, D. A. Kim, J. M. Susskind, A. K. Anderson (2009). In Bad Taste: Evidence for the Oral Origins of Moral Disgust Science, 323 (5918), 1222-1226 DOI: 10.1126/science.1165565

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The Sacrifice of Admetus

How the evolution of altruism reveals our noblest qualities

Heracles battles Death for generosity's sake
* This piece has been included in the 2007 Open Laboratory: The Best Science Writing on Blogs. For information on how to purchase or download a copy click here.


Whereas great scientific theories stand the test of time when they accurately predict the natural world through repeated empirical trials, great literature transcends the ages when it speaks to universal qualities of human experience. Such inspirational works can also, without the authors realizing at the time, reveal the sublime beauty and tragedy of our evolutionary drama. Few classical authors have tapped into this zeitgeist of biological experience as the Greek tragedian Euripides. The conflict between male and female reproductive strategy and the horrific choice of maternal infanticide is powerfully presented in the story of Medea (which waited some 2,400 years before being elucidated as an adaptive strategy in primates by the incomparable Sarah Hrdy). Electra chronicles the bitter feud between parent and child that would later be revealed as encompassing a biological reality by Robert Trivers in Parent-Offspring Conflict Theory. And Helen, the haunting tale of Helen of Troy's fateful decision, evokes the evolutionary importance of female mate choice revealed through Darwin's theory of sexual selection.

However, despite his focus on tragedy, Euripides could also reveal what we as a species have long prided ourselves as a uniquely transcendent gift: generosity even amidst the most terrible of circumstances. In his lesser-known work Alcestis, Euripides has the great hero Heracles (the Greek Hercules) arriving to the home of Admetus, the King of Pherae in Thessaly. Not realizing that his wife and true love, Queen Alcestis, has just been snatched by Death at a young age, Heracles asks his dear friend for harbor and a reprieve from his many adventures. Though wrought with grief, the tenderhearted Admetus cannot deny his friend the generosity of his home and so hides his mourning for the benefit of the visiting demigod. Ignorant of the great pain felt throughout the household, Heracles unwittingly offends his hosts with his Dionysian joviality only to be clued in by one of Admetus' less obedient servants. Overwhelmed by his breach of such generosity, Heracles descends to the Underworld to confront the "black and wingèd Lord of Corpses" and wrestle the dearly departed Alcestis from Death's icy grasp. Heracles understood the depth to which Admetus had sacrificed his own well-being for the sake of hospitality, and not even Death would prevent him from honoring his debt.


Alfred Russell Wallace and Charles Darwin
Such beneficence, in a decidedly less epic but nonetheless important way, has likewise been shown in the life of the great bard of biology himself. Having spent more than twenty years privately exploring the evidence for evolution, only mentioning his heretical research to his closest friends, Charles Darwin was faced with one of the great moral challenges in the history of science. In the summer of 1858 Darwin's collected work on the topic of natural selection exceeded a quarter of a million words (roughly five hundred pages), and was only half completed, when a parcel arrived from a young naturalist working in Borneo by the name of Alfred Russell Wallace. To Darwin's surprise he found that Wallace had independently developed a theory of natural selection (which he referred to as "progression") that outlined what Darwin had spent countless hours elucidating. Scientific culture places a premium on primacy of authorship and here Darwin was holding in his hand a document that could undermine the originality of his life's work.

Darwin knew what was at stake when he wrote to his friend and mentor Charles Lyell that Wallace "could not have made a better short abstract! Even his terms now stand as Heads of my Chapters. . . So all my originality, whatever it may amount to, will be smashed." But in an act that evokes Admetus' generosity, Darwin continued by stating that, "he does not say he wishes me to publish, but I shall, of course, at once write & offer to send to any Journal." And so Wallace's outline was included alongside an abstract of Darwin's theory and presented jointly before the Linnaen Society on July 1, 1858. On the Origin of Species was published just over a year later, the first edition selling out on the day of its release.

Ironic though it may be, the very act of generosity which gave origin to the Origin has posed tremendous difficulty to evolutionary biologists ever since. What Martin Luther King, Jr. described as a "walk in the light of creative altruism" has seemed, to many, contradictory to the "selfish gene" approach of natural selection. From a gene's-eye view of the world only those traits that are successful for an individual organism and allows the maximum level of reproductive success will live on in subsequent generations. Any trait that influenced one to benefit others at their own expense would be at a disadvantage compared to individuals who merely accepted the assistance and failed to reciprocate. The schoolyard dictum that "cheaters never prosper" wouldn't seem to have any place in such a system.


Chimpanzees show spontaneous altruism
Much ink, and many hours in the field, have been spent working to resolve this seeming conflict. The latest papers to do so, hitting the presses back-to-back and reinforcing each other in a fitting metaphor of the mutual assistance they document, highlights how this perceived conflict is really no conflict at all. The first to be published (on June 26, 2007 in the public journal PLoS Biology) was by Felix Warneken, Brian Hare, Alicia P. Melis, Daniel Hanus and Michael Tomasello of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. In their study they compared the innate predisposition for generosity in wild-born adult chimpanzees (Pan troglodytes, named for another Greek demigod) and human infants (aged 18-months).

The researchers set up identical conditions by which their Pan and Homo subjects observed an unfamiliar person stretching to reach an object just beyond their grasp. In multiple individual trials the researchers recorded the frequency at which each group of 36 subjects would offer their assistance by retrieving the desired object and handing it to the stranger. Contradicting previous studies of chimpanzee altruism, the researchers found no significant difference between us and our evolutionary cousins. This result was upheld even when the subjects had to put in some effort, climbing over a series of obstacles, in order to deliver the object. In a variation on these initial trials the researchers also offered the subjects a reward to illicit their assistance (toy blocks for the infants and bananas, of course, for the chimpanzees). In both cases the only significant factor was whether the subjects observed the stranger attempting to reach the distant object; a factor that chimpanzees and infants both responded to selflessly. Offering a reward for their assistance had no effect on this display of generosity. Service, it seems, was its own reward.

However, perhaps the chimpanzees had previously learned to obey human researchers in their time spent under semi-wild conditions? Would chimpanzees go out of their way to help other chimpanzees? To test this possibility the researchers constructed a door that could be opened by pulling a chain in order to access food on the other side. The researchers fastened this chain to a peg that could only be removed by a second chimpanzee in an adjoining room. In order to access the food the first chimpanzee would have to rely on assistance from the second, who gains nothing in the bargain. As before, 8 out of 9 individuals consistently helped a stranger (this time of their own species) if they saw they needed help. This, the authors reason, suggests that "the roots of human altruism may go deeper than previously thought, reaching as far back as the last common ancestor of humans and chimpanzees."

But could the roots of altruism go back even further? Apparently yes, as suggested by an additional study appearing in PLoS Biology on July 3 by Claudia Rutte and Michael Taborsky at the University of Berne, Switzerland. In a study entitled "Generalized Reciprocity in Rats" the Swiss biologists constructed a similar cooperative task as used for the chimpanzees. A baited tray was attached to a stick that one rat could pull in order to bring food within range for a second, unrelated rat's benefit. Rutte and Taborsky then conducted subsequent trials to see how often rats who had benefited in the past would be willing to help other rats in the future, the Rattus norvegicus version of the movie Pay It Forward. On average rats were 21% more likely to help strangers if they had received such help themselves.


Maasai pastoralists share meat throughout the community
These findings seem to fly in the face of previous theory suggesting that individuals wouldn't perform an altruistic act unless they could expect such acts to be repaid. Known as reciprocal altruism, it has traditionally been held that an individual (human and non-human alike) would only be likely to help another if the recipient had previously shown they wouldn't take advantage of such generosity. This meant that only group residents whom the individuals had previous experience interacting with would warrant their aid. It was solely among kin members, depending on the frequency of shared genes, that individuals would behave altruistically without reciprocation. However, in both PLoS Biology papers, altruism was being displayed for the benefit of total strangers. And in the case of rats the decision to offer anonymous help was determined by how much anonymous help they'd already received. Rather than contradicting reciprocal altruism, what these studies instead suggest is an expansion of the evolutionary social contract. In an environment of cooperative strangers it pays to be cooperative yourself.

While much has been made of the Darwinian phrase "survival of the fittest" suggesting that natural selection operates purely through aggressive competition, credit for the term must go to the British sociologist Herbert Spencer who had a dubious political ax to grind ("Social" Darwinism remains as his misguided legacy). However, Darwin's Origin preferred the more neutral "struggle for existence," which evokes a race against the elements rather than between individuals. It is only through Spencer's understanding of natural selection that cooperation and altruism pose a problem. For Darwin, cooperation between individuals could be an adaptive strategy in many environments as individual reproductive success increases through the safety and support of the group. Such group dynamics have been examined in detail by Robert Sussman and Audrey Garber published in the edited volume The Origins and Nature of Sociality (which Sussman also co-edited). In their metanalysis including seventy-eight published studies that covered twenty-five genera and forty-nine species of non-human primates they determined that prosimians, monkeys and apes spend the vast majority of their social lives in cooperative interactions. The study also showed that the amount of social aggression was statistically insignificant, concluding that "affiliation is the major governing principle of primate sociality and that aggression and competition represent important but secondary features of daily primate social interaction."

It was in Darwin's second great treatise on natural selection, The Descent of Man, that he offered this very line of reasoning that would wait 130 years to return full circle. With the knowledge that human and non-human animals alike were often illuminated by such walks of creative altruism, Darwin suggested that "those communities which included the greatest number of the most sympathetic members would flourish best and rear the greatest number of offspring." It is this relatively unacknowledged aspect of Darwin's theory that offers us hope in troubled times. For as surely as aggression and greed are part of our human character, so also is our capacity for cooperation and generosity.


Such an evolutionary legacy is rightly explored and celebrated through our great works, scientific and literary alike. In this way a chimpanzee reaching across species lines to help a human stranger in need can be viewed with the same appreciation as a Samaritan woman reaching out to offer water to a traveling Jewish mystic in breach of the social customs of her time. And, just as a notoriously self-indulgent demigod will transcend the boundaries of the living to repay his host's hospitality, so will a beady-eyed vermin transcend its (clearly unjustified) reputation to help a stranger with food. Through this very idea of generosity we witness how evolution can reveal our noblest of attributes. As Euripides expressed in his play Temenidae (of which, like the fossil record, only fragments remain), "When good men die their goodness does not perish, but lives though they are gone." The sacrifice of Admetus persists today as our evolutionary inheritance thanks to an unbroken chain of cooperative ancestors, who even Death himself could not prevent from sharing their gift with us.

For more on this topic see my posts here and here.


References:

Felix Warneken, Brian Hare, Alicia P. Melis, Daniel Hanus, Michael Tomasello (2007). Spontaneous Altruism by Chimpanzees and Young Children PLoS Biology, 5 (7) DOI: 10.1371/journal.pbio.0050184

Claudia Rutte, Michael Taborsky (2007). Generalized Reciprocity in Rats PLoS Biology, 5 (7) DOI: 10.1371/journal.pbio.0050196

Sussman, RW, Chapman AR (2004) The nature and evolution of sociality: Introduction. In: The Origins and Nature of Sociality. Ed. by RW Sussman and AR Chapman. Aldine De Gruyter: New York, pp. 3-19.

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A Natural History of Anarchy - Part I

Evolution, Cooperation and Social Change

“If the misery of our poor be caused not by the laws of nature,
but by our institutions, great is our sin.”

- Charles Darwin
All political and economic philosophies are based on fundamental assumptions about human nature. Early assumptions were based on the premise that a supernatural entity fashioned man in His image but that this creation was flawed. As a result, while we may strive for perfection, the harmony we seek is unattainable without embracing the Supreme Being and His law. Throughout recorded history, all-too-human tyrants have used such views to their political advantage.

Even in the Republican systems that emerged out of the Enlightenment, the premise that there must be a class of rulers and a class to be ruled is the established norm (the modification being that the ruler is approved first by the populace rather than chosen through nepotism). Totalitarian regimes are predicated on the assumption that humans are innately selfish and easily swayed by rival factions thus requiring a unitary executive that, through his singular and enlightened moral vision, will fashion social life in the public’s best interests. [1] State communism (as implemented by Joseph Stalin, Mao Zedong or Pol Pot) followed many of these totalitarian illusions and further assumed that human beings were infinitely malleable and thus able to be forged anew through “reeducation camps” that would benefit society by molding human will around the interests of the state. [2]

Only the political philosophy of anarchism assumes that human nature is basically rational and compassionate, leading to a just society through the free association and participation of all citizens. [3] Anarchy, while assumed by most people to be synonymous with chaos, is actually from the Greek root arkhos, or rulers, and is therefore defined simply as “no rulers.” Modern political classifications place anarchy as Libertarian Socialism, libertarian in the sense of limited or no government influence and socialist in the economic view of equitable distribution of resources and the direct confrontation of oppression.


This makes anarchy a fusion of conservative and liberal ideals; a combination of Ronald Reagan or Ron Paul’s vision that government should be drowned in its own bathwater with the revolutionary action inherent in social justice movements from Thomas Paine and Daniel Shays to Malcolm X and Cesar Chavez. Anarchism has many forms, but advocates generally agree that an anarchist society should consist of nonhierarchical free association, self-government, workers councils (rather than bosses), participatory economics and environmental sustainability. But is such a seemingly utopian ideal consistent with a modern understanding of human nature?

According to Noam Chomsky, international bestselling author of Hegemony or Survival, "In this possibly terminal phase of human existence, democracy and freedom are more than just ideals to be valued - they may be essential to survival." The human experiment is at a crucial turning point where we have within our power the ability to choose whether we continue towards inevitable self-destruction or reconsider our actions and move towards a vision of human freedom and sustainability. As we move towards this vision it is important that we inform ourselves of our evolutionary history, of previous experiments that species have engaged in during our collective legacy.

If we are to avoid the fate of 99.99% of life on this planet (as most species that have ever existed in our 4.6 billion year history are now extinct) we must use our creativity and our wisdom to re-imagine what it means to be human and what it means to interact with our environment. We are the first species to ever be conscious of our own potential extinction. This is a source of optimism rather than despair, for while our creativity and innovation are the roots of our own destruction they are also the wellspring of a new world that merely awaits our ability to imagine.



[1] McCormick, J.P. (1994). Fear, Technology, and the State: Carl Schmitt, Leo Strauss, and the Revival of Hobbes in Weimar and National Socialist Germany. Political Theory 22(4):619-652.
[2] Tucker, R.C. (1956). Stalin and the Uses of Psychology. World Politics 8(4): 455-483; Bracey, D.H. (1985). The System of Justice and the Concept of Human Nature in the People’s Republic of China. Justice Quarterly 2(1):139-144; Clayton, T. (1998). Building the New Cambodia: Educational Destruction and Construction Under the Khmer Rouge, 1975-1979. History of Education Quarterly 38(1):1-16.
[3] Gould, C. (1989). Rethinking Democracy: Freedom and Social Cooperation in Politics, Economy and Society. Cambridge University Press; Turner, S. (1998). Global Civil Society, Anarchy and Governance: Assessing an Emerging Paradigm. Journal of Peace Research 35(1):25-42.

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The Blind Leading the Blind

Creationists spin-doctor the evolution of blind cave fish

Image: Jesus! vs. Darwin! by The Searcher
It's a tired old routine, yet time and again the same argument is taken off the shelf, dusted, buffed and then presented with a sly smile as if it were something new. Evolution, it's asserted, is only progressive and builds on earlier adaptations in its march forward through natural history. Therefore, if there is any evidence that a species adapted "backwards" it must mean that natural selection is flawed. However, the fallacy in this argument is that natural selection has nothing to do with progress, it's merely one of the mechanisms by which species successfully adapt to their environment. Genetic mutations don't have a direction in mind when there's a mistake in transcription or as a cosmic ray collides with a nucleotide of cytosine. If the organism succeeds once this genetic alteration occurs, they'll reproduce and spread the mutation further. It says nothing about a march of progress.

Those who oppose evolution without bothering to first understand it have repeatedly hailed this fallacy as a triumph. It was the centerpiece of the laughably bad polemic Icons of Evolution by intelligent design advocate Jonathan Wells (a detailed review can be found here). Now the same sickly horse has again been prodded out to market despite how often such duplicity has been exposed in the past.

In the latest edition of Current Biology (subscription required), Richard Borowsky found that blind cave fish whose genes for vision have mutated over the course of evolutionary history could have their vision returned by interbreeding with other blind cave fish with differently mutated genomes.

According to the review in Science Daily:

The study examined four populations of blind cave fish, Astyanax mexicanus, which inhabit different caves in northeast Mexico. Blind for millennia, these fish evolved from eyed, surface fish. The researchers' genetic analysis showed that the evolutionary impairment of eye development, as well as the loss of pigmentation and other cave-related changes, resulted from mutations at multiple gene sites.

In order to gauge how genetic make-up could bring about the restoration of vision, the researchers created hybrids of the different cave fish populations. Among these various hybrids, they found that nearly 40 percent in some hybrid crosses could see.

Fascinating stuff. These results support the view that different species each adapt to their environment in unique ways, precisely as evolutionary theory predicts. However, the results must have been a little too uncomfortable for intelligent design creationists because immediately both Uncommon Descent and Creation Ministries International (which produces the young Earth themed Journal of Creation) hit upon the news as evidence that evolution must be wrong. Dr. Carl Wieland, writing for Creation Ministries, objects to this evidence of multiple evolutionary trajectories and insists that:

It would not take long at all, once a group of fish are cut off from the daylight by some geological circumstance, for an eye-losing mutation to be established by natural selection as described.

Of course, if Dr. Wieland had bothered to read the actual article (rather than merely the press reports that creationists are so fond of) he would have found that Astayanax mexicanus “evolved from eyed, surface-dwelling forms which only reached the area in the mid-Pleistocene,” that is, between 600,000 to 1 million years ago. How does Borowsky know this? This is where references matter. Earlier research by Ulrike Strecker and colleagues, published in Molecular Phylogenetics and Evolution (subscription required) showed that mutations occur in freshwater fish at a rate of 1.5% per million years. By analyzing the differences in cytochrome b genes between currently living species and then dating the nearest common ancestor of each in the fossil record, Strecher et al. proposed that Astyanax first arrived in the Yucatan no earlier than 900,000 years ago, just as Borowsky states. How can Wieland be so certain that “it would not take long at all” for such mutations to occur? Not presenting any evidence to back up his assertion we can only wonder how he determined this. But then, already walking down a blind alley, Wieland goes on to make matters even worse by asserting that:

Cave fish have arisen by processes that in fact demonstrate the opposite [of natural selection]—deterioration of function, consistent with the ‘natural’ direction of genetic change in a fallen world.

Here the good spin-doctor rests on the fallacy that has failed so miserably for so long: if evolution is about building up then mutations that result in deterioration must prove evolution is false. But even more than this, the fact that these cave fish have lost their vision supports Dr. Wieland's contention that the sin of man has affected all of creation. If you’re a little confused then you’re in good company. Apparently Wieland (and other Young Earth Creationists in general) think that Adam and Eve’s violation of God’s dictates resulted in the beginning of genetic change. Prior to the “fall” there was no aging, no genetic deterioration and no death. Far from revealing additional evidence to the already weighty tome of evolutionary theory Wieland instead sees evidence of God’s divine plan. And Creationists accuse scientists of imposing their views on nature? Of course, why God in his infinite wisdom would feel it necessary to put out the eyes of a few Mexican fish to punish humans for their hubris is anyone’s guess. But I suppose that's why it's called blind faith.

References:

Borowsky, R. (2008). Restoring sight in blind cavefish. Current Biology 18: R23-R24

Strecker, U., Faundez, V.H. and Wilkens, H. (2004). Phylogeography of surface and cave Astyanax (Teleostei) from Central and North America based on cytochrome b sequence data. Molecular Phylogenetics and Evolution 33(2): 469-481. doi:10.1016/j.ympev.2004.07.001

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Gorillas Use Tools to Fight Human Invaders

Suggests earlier use of tools in human evolution.

Don't mess with other primates, human.
Wild gorillas have been seen using "weapons" for the first time, giving a new insight into how early man learned to use sticks and stones for fighting and hunting millions of years ago. Researchers observed gorillas in the Cross River area of Cameroon throwing sticks, clumps of earth and stones at human "invaders". It is the first time that the largest of the great apes has been seen to use tools in an aggressive way.

Experts believe that our ancestors may have learned to use sticks and stones in a similar way to frighten away predators. The scientists noticed the unusual behaviour during a three-year study. They believe the animals might have learned to throw objects from humans who were seen throwing stones at the gorillas.

Jacqueline Sunderland Groves, from the University of Sussex in Brighton, a member of the Wildlife Conservation Society team, said:

"The area is largely isolated from other gorilla groups, but there are herdsmen on the mountain. In one encounter a group of gorillas threw clumps of grass and soil at the researchers while acting aggressively. Another gorilla threw a branch. A third encounter saw the gorillas throwing soil at a local man who was throwing stones at the apes."

A gorilla was seen to use tools once before in the Congo, using sticks to test the depth of water and to cross swampy areas. The findings suggest that the use of tools may predate the evolutionary split between apes and humans six million years ago.

Source: UK Telegraph

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Tool-Wielding Chimps Reflect Early Human Behavior

Pan the Tool-Maker creatively adapts to harsh environments

Chimpanzees use tools in many environments (here shown with hammer and anvil).

Image: Clive Bromhall/Oxford Scientific Films

A new report from the Proceedings of the National Academy of Sciences reveal multiple tool technologies employed by chimpanzees in their harsh savanna environment, findings that may help researchers understand how our hominin ancestors coped with a changing climate.

As Science Daily reports:

A team of researchers including University of Wisconsin-Madison anthropologist Travis R. Pickering reports evidence of tool use among rare savanna chimps to harvest edible tubers, roots and bulbs.

The finding is important because it chips away at behaviors once seen as uniquely human. It supports the notion that chimpanzees, our closest living evolutionary relatives, can serve as models for understanding some aspects of the lifestyles and behaviors of the earliest members of the human family.

The new study demonstrates that "the understanding and capability to exploit these resources were very likely within the grasp of the first chimp-like hominids," argues Pickering. "It was widely believed that it is a uniquely human adaptation to use tools to dig these things up."

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Situational Science Man

Your Sunday Skepticomic from Doonesbury.

(click image to enlarge)


To view last Sunday's comic click here.

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Wedging Religion into Science (Again)

Answers in Genesis promotes miseducation in America

Image: Tom Toles/Washington Post
As AiG is currently attacking public science education (and, surprise, not because our science standards are ill preparing our students) I thought it would be appropriate to repost this article from the last time they tried to pull this nonsense. It's organizations like this that continue to ensure that our nation's understanding of evolution reaches a whopping 33rd out of 34 countries (just ahead of Turkey).

--

Ken Ham, founder of Answers in Genesis and creator of the Creation Museum, is currently promoting his new book by submitting sample chapters on his group's website. Entitled War of the Worldviews the book teaches Young-Earth biblical literalists strategies on how to argue against the evidence for evolution.

At the beginning of the chapter he chastises Christians for adopting “flaky evidence” to support their views.

Over the past several years, some so-called “evidence” for creation has been shown not to be reliable. Some of these are

* supposed human and dinosaur footprints found together at the Paluxy River in Texas.
* the small accumulation of moon dust found by the Apollo astronauts.
* a boat-like structure in the Ararat region as evidence of Noah’s Ark.
* a supposed human handprint found in “dinosaur- age rock.”
* a dead “plesiosaur” caught near New Zealand.

Most well-meaning, informed creationists would agree in principle that things which are not carefully documented and researched should not be used. But in practice, many of them are very quick to accept the sorts of evidences mentioned here, without asking too many questions.

Initially I was impressed. Could Ham be urging his readers to seriously engage the scientific evidence in an effort to make reasoned arguments? Alas, this was not the case. His answer to the flaky evidence that creationists have long used is, rather, don’t use any evidence at all!

When someone says they want “proof” or “evidence,” not the Bible, one might respond as follows: “You might not believe the Bible, but I do. And I believe it gives me the right basis to understand this universe and correctly interpret the facts around me.”

Let’s just apply that logic in another way, shall we? There are few scientists today who would argue that bats are actually birds rather than mammals. Pesky issues regarding bone structure and their nursing of infants make this a difficult theory to gain support for. But suppose all of the science isn’t in, the same way that all of the science isn’t in about continental drift (has anyone actually watched continents move?). Isn't there room for an alternative theory?

The Bible clearly states (Deuteronomy 14:11 & 14:18) that bats truly are birds, and they’re unclean birds at that. So by Ham's logic, this evidence deserves equal weight to that of the so-called experts. But as you’re answering a question on your zoology midterm that asks “Are bats birds?” (this is a very introductory level class) and you answer “Yes” I would encourage you NOT to attempt Ham’s suggested response to your science teacher after it's been marked wrong.

Likewise, a solid majority of astronomers (perhaps a little more) accept the evidence that the Earth spins on its axis daily and orbits around the sun. However, the Bible does clearly state that “all the earth: the world also shall be stable, that it be not moved.” (1 Chronicles 16:30). In fact, there are several passages that lend credence to the potentially lucrative field of Christian Geocentric Science (see Job 9:6-7; Job 37:18; Psalm 19:4-6; Psalm 93:1; Ecclesiastes 1:5; you get the picture).

So when someone claims there is evidence for this so-called Heliocentric Theory (afterall, it is only a theory and it's not as though anyone can feel the Earth move) you can simply tell them,

“You might not believe the Bible, but I do. And I believe it gives me the right basis to understand this universe and correctly interpret the facts around me.”

Is it legitimate to use such a response? Should the federal government force teachers to mention this competing theory in science classes? If your answer is yes, than you’ve probably purchased Ham’s book and added to his reported $125,000 yearly salary.

In a related note, as Ham is encouraging the Young-Earthers to back away from “flaky evidence” he might want to take his own advice. During a lecture criticizing the evidence for evolution last year Ham laid the following egg:

He pointed out cave drawings of a creature resembling a brachiosaur to make the case that man lived alongside dinosaurs after God created all the land animals on Day 6.

Cave drawings are evidence? That's what that crank von Däniken tried to pull. This would simply be comic, except for one thing. They're not in on the joke and are teaching hundreds of thousands of children at home schools across the country this very rubbish. They're forming think-tanks, founding law schools and funding politicians and they will not listen to reason. They're being taught not to.

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Evolutionary Lap Dance

Study suggests women display sexual cues during estrus

Lap dancers earn larger tips when men sense fertility

In my earlier post, Eye of the Beholder, I pointed to new research showing that women are most attracted to individuals other than their partners while in estrus, the most fertile period of a woman’s menstrual cycle. Their eyes betrayed their attraction to others even under controlled settings. Now it seems that estrus causes men’s eyes to widen as well.

Publishing in the journal Evolution and Human Behavior (pdf), evolutionary psychologists Geoffrey Miller, Joshua Tybur and Brent Jordan collected data on the tips received by lap dancers who were currently taking birth control and those who were naturally cycling. Those dancers who were at their most fertile period received significantly more tips than both dancers on birth control and those at other points in their cycle.

As the authors wrote in their study:

When women and men interact intimately over the course of several minutes through conversation and body contact, women apparently either “signal” or “leak” cues of their fertility status, and these cues influence spending patterns by male consumers. These results argue against the view that human estrus evolved to be lost or hidden from males.

However the study has several limitations, as the authors readily admit. The sample size included only 18 individuals which could result in “false positives,” or finding significant differences where there wouldn’t be in results from a larger population. Secondly, the tip earnings and cycle phase were self-reported by the dancers themselves. Knowing which phase of the cycle you’re in can be difficult to determine (or so I’ve been told) and any mistaken estimates are further compounded when the sample size is so small.

Nonetheless, it would be remarkable if women didn’t show some indications of their reproductive status during their peak of fertility. All female mammals display distinct behavioral and physiological cues during their fertile period that increase their reproductive success as a result. For example many primates, including our closely related chimpanzee and bonobo cousins, will develop large estrus swellings during their fertile period and will be more likely to approach the males they find desirable. Rhesus macaque females will vigorously court males during estrus, even using physical aggression if males reject their advances. Also, lionesses will actively seek out up to 100 matings per day with multiple individuals during their one-week of peak fertility (something that was edited out of The Lion King).

Bonobo sexual swellings coincide with greater sexual interest in males and females

Image: Vanessa Woods
This study doesn’t suggest that the dancers were more attracted to their customers while in estrus (or attracted to them at all), merely that males could detect something irresistibly alluring, more so than during other times, and responded with their wallets.

Our society typically views women’s sexuality as either shameful or reserved for men’s enjoyment (as I’m sure the women in this study know all too well). However, in an ironic twist, this tentative evidence of estrus signaling among lap dancers emphasizes the personal empowerment inherent in the evolution of female sexuality. For thousands of generations those women who displayed a healthy sexual desire during their most fertile period were ultimately more successful in the evolutionary dance. This legacy remains visible today, even in women who want nothing more from the males in their vicinity than a decent tip.

Reference:

Geoffrey Miller, Joshua M. Tybur, Brent D. Jordan (2007). Ovulatory cycle effects on tip earnings by lap dancers: economic evidence for human estrus? Evolution and Human Behavior. doi:10.1016/j.evolhumbehav.2007.06.002

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They've Got a Bone to Pick

Boneyard #6 is up at Fish Feet


En garde, skin jobs!

Had a hankerin' to read up on the mysterious world of fossils? Well here is your chance.

GrrlScientist at Living the Scientific Life reviews the recent discovery that velociraptors had feathers. Steven Spielberg may need to add some CG effects to the 15th anniversary edition of his film.

Brian at Laelaps has a wonderful post entitled Of Feathers, Nests and Dinosaurs. Pour a tall cold one, sit back and prepare to be blown away.

Any fans of They Might Be Giants? Kevin and Christopher at The Other 95% have an amusing ditty called Receptaculites sung to the tune of "Particle Man".

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