Capuchin monkey tools

One of many arguments for the uniqueness of homo sapiens among the animals is that we use tools. But that claim has long since gone by the wayside.

Now we hear that Brazilian capuchin monkeys haven taken using tools to "the next level," as management consultants like to say. Kate Wong reports in The artifacts bear a striking resemblance to objects produced by our ancestors Scientific American Online 10/21/2016:

The monkey is a wild capuchin in northeastern Brazil’s Serra da Capivara National Park, where these animals have long been known to use rocks for a wide range of activities, from cracking open nuts and digging for roots to catching the attention of potential mates. Other nonhuman primates, including West African chimpanzees, also use rocks as tools in the wild. But the Serra da Capivara capuchins are the only ones that scientists have seen banging rocks together to break them — an activity previously thought to be exclusive to members of the human family. Humans do it to create sharp-edged tools for cutting things. The capuchins, in contrast, never use the flakes they make. Exactly why the monkeys want to break the rocks is unclear, but they often pause from smashing to lick the surface of the embedded stone, perhaps in pursuit of mineral dust generated by the impact.

Yes, you silly humans, we can make tools, too!

But she tells us that we humans are still Exceptional when it comes to chipped stone:

Although the capuchin discovery demonstrates that nonhuman species can accidentally produce fragments of rock that look just like human-crafted cutting tools, that does not mean the human-made tools are not special, Harmand cautions. Even if human ancestors started creating flakes by mistake like the capuchins do, there was something that made them realize they could put them to use and even make new tools to suit their purposes. Moreover, human technology evolved from the comparatively simple tools seen at Lomekwi and at Oldowan sites to handaxes with carefully shaped cutting edges a million years later, and eventually to the elaborate machinery we have today. Why didn’t technology evolve to the same degree in chimps and monkeys, Harmand asks. Why did humans alone take it to such an extreme?

Yes, there was a moment in human evolution when "banging rocks together to break them" was high-tech innovation.

Evolution and social sexuality

Articles about what makes people attractive to potential sexual and/or life partners are good click-bait.

(Update 07/16/2014: post edited for grammar and clarity.)

Salon features one by Jesse Bering called The secret to successful flirting 07/12/2014. It appeared in his Scientific American blog as Voices Carry (Signals of Your Sexual Intent and Reproductive Value) 07/10/2014, which is a more descriptive title for the article's content.

The Scientific American logo always adds weight, and he writes for them. Although this following piece by the same author is clearly tagged as an opinion piece that is the writer's own: Jesse Bering, A Good Man is Hard to Find, So Here’s an (Evolutionary) Tip 07/15/2014. And seeing that he's written a book called Perv (?!) adds another cautionary note.

While I certainly think that questions of sex and sexual attraction play an huge role in society, Bering's approach strikes me as confusing biological, evolutionary and social factors. For instance, in the "Voices Carry" piece he's discussing research on how men's and women's voices modulate when talking to each other:

So how do Leongómez and his co-authors interpret this puzzling effect? Why, from an evolutionary perspective, of course. "Producing a low pitch at some point during an interaction [with an attractive female] might provide sufficient indication of physical masculinity while freeing men to 'play' with their pitch ... because low-pitched masculine voices might be associated with aggression, such modulation could potentially enable men to signal both their masculinity and lack of threat simultaneously." In other words, "Hey, sexy lady, hear this? Hear how I’m sounding right now? That's right: I'm a virile, testosterone-fuelled male specimen of our species but, cross my heart, I'll be sweet to you ... and our future offspring." And indeed, a group of naïve female listeners asked to judge the verbal recordings of male wooers found those with the most significant pitch variability the most attractive.

This has the virtue of sounding empirical and based on hard-nosed science.

But there are actually a lot of assumptions at work. For instance, in the "evolutionary perspective," did low pitches signal "physical masculinity" for, oh, the last 300,000 years in the ancestry of homo sapiens? Did homo sapiens and our ancestors for the last million years live in conditions where the females were in a position to meaningfully choose their preferred mate? If not, just how did these preferences evolve? And are we talking about biological evolution here or social evolution?

Part of me wonders if I should be griping about this. Because in these days of the Republican Party's anti-science poliical-religious jihad, I wonder if I shouldn't just be glad to see someone talking in a context that accepts evolution as a real process in history and biology.

But this kind of approach raises red flags for me in several ways. One is that whenever I see someone explaining romantic interactions between men and women in this way, I wonder if I'm not looking at some version of "evolutionary psychology", aka, "sociobiology", aka, Social Darwinism.

Also, one of the practical problems with understanding evolution, a key concept in science, is that there's a great temptation in describing evolution, especially in popular presentations, to resort to language suggesting teleology or the inheritance of acquired characteristics. Or to talk about evolution as a conscious agent. As in: this fish developed this characteristic to be able to evade predators. Which raises the obvious question, how did the fish's ancestors evade predators before that? It's important to recognize that successful evolution means that a given species or sub-species grouping was able to survive and reproduce. It doesn't mean that every aspect of the species is the best conceivable adaptation. It's that it was advantageous enough, without features that were so disadvantageous that it prevents survival and reproduction. It certainly doesn't mean that adaptations were in some way designed to maximize an individual's advantage in 2014 forms of family and sexual practices.

So when Bering describes the voice modulation patterns he's discussing as a way for the male of the species to say, "Hey, sexy lady, hear this? Hear how I'm sounding right now? That's right: I'm a virile, testosterone-fuelled male specimen of our species but, cross my heart, I'll be sweet to you ... and our future offspring," I have to wonder if there aren't a few too many corners being cut in the description! Among other things, he seems to be trying awfully hard to give the piece a how-to-pick-up-chicks sound. Which Salon's headline writer also seems to have picked up on.

He also be seems to be balancing a lot of speculation on top of a fairly limited finding. Like presumably most readers of the article, I haven't checked the research he's citing. But he seems to be taking an interesting data point, a finding that men's voice patters show certain modulations in the presence of a woman they find attractive, and speculating fairly freely about what it might imply about sexual evolution. And while the flirtation angle is click-bait fun, the explanation doesn't work without a lot of other findings beyond even confirmation by other similar studies.

For instance, without validating a similar pattern in various languages and numerous cultures and different courtship patterns, it couldn't be held to be a general features of homo sapien evolution. The study he referenced was in English and Czech, which are at least from two separate language groups. And can such a pattern be confirmed over time, through literature or decades of "talkie" movies? Or could it be some effect of dramatic patterns in movies or voice modulations in widely-shared popular music? The fact that a similar voice modulation pattern was found in some (apparently heterosexual) women when speaking to certain other women would seem to raise a bigger question about the mate-selection interpretation in male-female interactions than Bering's article acknowledges.

The "Good Man" post is also about mate selection, in this case reporting on a study on how women's preferences in men are shaped by other women's ideas of which men are desirable. This one is less interesting than the voice-modulation one. Gee, people are influenced by how their peers react to the opposite sex? Who could have guessed?

But I also have to wonder on this one if Bering isn't too quick to read social assumptions back into millennia of biological evolution:

A final caveat is that female mate copying didn't seem to play a role for women with high "self-perceived mate value" (or "SPMV"). Women who are convinced—wrongly or rightly—that they're especially hot aren't so easily swayed by other women's views of a man when rating that man’s desirability. "Women with high mate value may be less likely to copy the choices of other women," speculate the authors, "if those women have lower mate values than themselves, and thus lower standards."

Meow. That sounds a bit harsh, but natural selection can be that way, I suppose.

The value of this speculation is, of course, heavily dependent on how an "SPMV" woman is defined. Does this mean that a narcissistic woman will put more effort into developing a personal appearance and other attributes to develop a high SPMV and her narcissism makes her pay less attention to the opinions of her peers? Does it mean a woman who's too smug (the "self-perceived" part) is more prone to making sloppier choices in mates because she's not gathering the right social intelligence from other women? Or does it mean that a self-confident woman with a rich array of social experiences will come to perceive herself as high-SPMV and also make her more (justifiably) confident of her own perceptions of potential mates so that she doesn't need to rely so much on her friends' superficial assumptions?

So many evolutionary questions, so little time!

And as long as we're looking at sex-and-science click bait, Scientific American also provides, Is Spring Fever Real? – Instant Egghead #68 07/28/2014:

Tags: evolution

New relative discovered! In this case, a mammal relative from 160 million years ago

It's this little critter, known as Juramaia sinensis; the name means "Jurassic mother from China," though presumably there were males, too:

Katherine Harmon reports in Jurassic Mammal Moves Back Marsupial Divergence Scientific American Observations 08/24/2011:

Although the exact evolutionary path from the early eutherian mammals has yet to be traced, [Zhe-Xi] Luo [of the Carnegie Museum of Natural History] noted that "Juramaia, from 160 million years ago, is either a great-great-aunt or a great-grandmother of all placental mammals that are thriving today."

Science Codex features a press release from the Carnegie Museum ont he discovery: Juramaia sinensis: 160-million-year-old fossil a new milestone in early mammal evolution 08/24/2011.

Harmon reports:

It also had a strange reproductive strategy—at least for that era. Instead of laying eggs (like a "monotreme" relative the platypus) or carrying tiny young to term in a pouch (like a "metatherian," a marsupial, such as a kangaroo), it was a "eutherian," which means that it bore full-term live young like most of today's mammals do, thanks to a nutrient-rich placenta.

Discovering a creature with such a developed placenta from that period was very significant. From the press release:

"Understanding the beginning point of placentals is a crucial issue in the study of all mammalian evolution," says Luo. The date of an evolutionary divergence - when an ancestor species splits into two descendant lineages - is among the most important pieces of information an evolutionary scientist can have. Modern molecular studies, such as DNA-based methods, can calculate the timing of evolution by a "molecular clock." But the molecular clock needs to be cross-checked and tested by the fossil record. Prior to the discovery of Juramaia, the divergence point of eutherians from metatherians posed a quandary for evolutionary historians: DNA evidence suggested that eutherians should have shown up earlier in the fossil record—around 160 million years ago. Yet, the oldest known eutherian, was Eomaia (Eomaia was originally described in 2002 by a team of scientists led by Zhe-Xi Luo and Carnegie mammalogist John Wible), dated to 125 million years ago. The discovery of Juramaia gives much earlier fossil evidence to corroborate the DNA findings, filling an important gap in the fossil record of early mammal evolution and helping to establish a new milestone of evolutionary history.

Juramaia also reveals adaptive features that may have helped the eutherian newcomers to survive in a tough Jurassic environment. Juramaia's forelimbs are adapted for climbing; since the majority of the Jurassic mammals lived exclusively on the ground, the ability to escape to the trees and explore the canopy might have allowed eutherian mammals to exploit an untapped niche.

Luo supports this perspective: "The divergence of eutherian mammals from marsupials eventually led to placental birth and reproduction that are so crucial for the evolutionary success of placentals. But it is their early adaptation to exploit niches on the tree that paved their way toward this success."

Tags: evolution, juramaia, mammals

Thanksgiving with Darwin

Charles Darwin's Bible

Roy Edroso takes an entertaining look at how Rightbloggers Fight War on Thanksgiving (And, Of Course, Muslim Obama) Village Voice 11/26/09. I didn't know that there was a mythical War on Thanksgiving along with the equally fictional War on Christmas. But why not? When you need something to be afraid of and are used to creating phantoms in the air, I guess one is as good as the other.

Darwin doesn't actually have anything to do with Thanksgiving. Though we can be thankful for his work, since he theory of natural selection forms a huge part of the basis of present-day science. But Edward J. Larson has a good piece out this week on the sometimes-uncomfortable meeting of Darwinism and Christianity, "I Had No Intention to Write Atheistically": Darwin, God, and the 2500-Year History of the Debate Religion Dispatches 11/24/09.

Darwin was open to the notion early on that humanity as well as other animal species could have evolved on a natural basis, a process that could be explained without resorting to divine intervention:

Alluding to William Paley’s analogy between a crafted telescope and the human eye, which was a key part of the Anglican theologian’s famous proof of an intelligent designer behind organic creation. Darwin then added, “Not believing this, I see no necessity in the belief that the eye was expressing designed.” Even human nature and mental ability might result from natural processes, he concluded.

The sequence in Darwin’s letter to Gray is telling. It passed quickly from observations of what seemed bad in nature (such as cruel animal behavior, which even devout creationists hesitate to blame on God) to ones about what seemed good in nature (such as the human eye, which Victorians typically credited to God), and then moved on to ponder the origin of what seemed best of all, human morality and mentality, which natural theologians typically hail as the ultimate gift and proof of the divine supernatural. In Origin of Species, Darwin avoided making comments about human evolution, fearing that they would prejudice readers against his general theory, but his private notes, essays, and letters reveal his longstanding fascination with the issue.

While the article is very good in describing the history of this conflict, I don't really like the next-to-last section "Humans are Survival Machines" in which he writes, "Today, Darwin’s sketchy social theories have matured by way of E.O. Wilson’s sociobiology and modern evolutionary psychology to become foundational for understanding in the social sciences." Uh, no, "sociobiology" and "evolutionary psychology" are nothing but cleaned-up terms for Social Darwinism, which is certainly not "foundational for understanding in the social sciences" or for understanding anything but Social Darwinism. The arguments that go by those terms are barely-updated versions of Victorian-era arguments that the current "traditional values" hierarchies of gender, class and (if you look closely) race are rooted in immutable biology. And it's hard to imagine that Darwin wouldn't have been embarrassed to see the sloppy, speculative reasoning that underpins most of their arguments.

What we've come to call fundamentalism, the notion that the Christian Bible should be read as though it were a history and science text, was also a 19th-century phenomenon like Darwinism. But it wasn't only in opposition to the theory of evolution and new astronomical and geological discoveries that it developed. Especially in Germany, scholars like David Friedrich Strauss (1808-1874) were analyzing the Scriptures with new historical and linguistic methods. Strauss' Life of Jesus (1835-1836) argued that the New Testament did not actually describe Jesus as God in human form, which is the basic Christian notion of the Incarnation.

The whole concept of history as describing accurately and analyzing the procession of actual events that took place was one that began developing with the modern age in 15th-century Europe and took centuries to establish itself as a more general understanding. (Keith Thomas describes some of this process in the print edition of the New York Review of Books, "Fighting over History" 12/03/09 edition) So those who felt uncomfortable with the religious implications of the historical-critical method of seeking to understand the Bible - a method which was by no means linked exclusively to atheism or strict materialist philosophy - began to articulate an understanding of the Bible that redefined it in more literalist terms than had been common among Christians before that.

Tags: christian fundamentalism, darwin, evolution