Human evolution

From Michael Greshko at National Geographic: “We’ve been looking for ape fossils for years—this is the first time we’re getting a skull that’s complete,” says Isaiah Nengo, the De Anza College anthropologist who led the discovery, supported by a National Geographic Society grant and the Stony Brook University-affiliated Turkana Basin Institute. Roughly the size of a lemon, the skull belongs to a newly identified species of early ape named Nyanzapithecus alesi. Some of its features resemble those of today’s living Old World monkeys and apes, and the face bears a striking resemblance to today’s infant gibbons. What’s more, N. alesi offers insight into early apes’ brains, the team reports in their study, published today in Nature. With a volume of Read More ›

From Heather Heying, weighing in on the Google foray into post-modern truth, which smacked an unwary engineer upside head, at Quillette: Should We “Stop Equating ‘Science’ With Truth”? Damore’s heresy turns on innate differences between men and women that have never been noticed by anyone in the history of human life on the planet except him. So, of course, the entire obsolescent traditional media melted down in shock. Heying: Evolutionary biology has been through this, over and over and over again. There are straw men. No, the co-option of science by those with a political agenda does not put the lie to the science that was co-opted. Social Darwinism is not Darwinism. You can put that one to rest. There Read More ›

From ScienceDaily: Hundreds of thousands of years ago, the ancestors of modern humans diverged from an archaic lineage that gave rise to Neanderthals and Denisovans. Yet the evolutionary relationships between these groups remain unclear. A University of Utah-led team developed a new method for analyzing DNA sequence data to reconstruct the early history of the archaic human populations. They revealed an evolutionary story that contradicts conventional wisdom about modern humans, Neanderthals and Denisovans. The study found that the Neanderthal-Denisovan lineage nearly went extinct after separating from modern humans. Just 300 generations later, Neanderthals and Denisovans diverged from each other around 744,000 years ago. Then, the global Neanderthal population grew to tens of thousands of individuals living in fragmented, isolated populations Read More ›

From ScienceDaily: Dr. Barr used computer simulation to model what the fossil record might look like over time in the absence of any climate change and found clusters of species originations that were of similar magnitude to the clusters observed in the fossil record. This means random patterns are likely under-credited for their role in speciation fluctuation, he said. Dr. Barr’s findings mean scientists may need to rethink widely-accepted ideas about why human ancestors became smarter and more sophisticated. “The idea that our genus originated more than 2.5 million years ago as part of a turnover pulse in direct response to climate change has a deep history in paleonthropology,” Dr. Barr said. “My study shows that the magnitude of that Read More ›

How do we think we know that a skeleton is the remains of a woman who has given birth? From ScienceDaily: The presence of parturition scars — marks often found on female pelvis bones — have commonly been used as an indicator of child birth. This technique is used in police investigations to narrow down the identity of human remains. … Ms McFadden also said that use of the method in archaeology could lead to historical inaccuracies. Despite the practise being in common use, particularly in the US, since first being proposed in the 1910s, a number of studies into parturition scars have resulted in conflicting findings. Ms McFadden reanalysed data used for those studies and found the scarring was Read More ›

From ScienceDaily: In the study, the researchers showed children and bonobos a small wooden box with a reward inside. Before opening the box, an experimenter performed some nonsensical actions over the box, such as waving a hand or tracing an imaginary line over it. Each participant was then given a box without any instructions. Most of the children spontaneously imitated the actions; in contrast, none of the bonobos made any attempt to copy any of the actions. “The fact that the bonobos failed to imitate demonstrates that even enhanced social orientation may not be enough to trigger human-like cultural learning behaviors,” notes Claudio Tennie, research group leader at the University of Tubingen, who coauthored the study when he was at Read More ›

From ScienceDaily: While it is accepted that humans appeared in Africa some 200,000 years ago, scientists in recent years have placed the approximate date of human settlement in Australia further and further back in time, as part of ongoing questions about the timing, the routes and the means of migration out of Africa. Now, a team of researchers, including a faculty member and seven students from the University of Washington, has found and dated artifacts in northern Australia that indicate humans arrived there about 65,000 years ago — more than 10,000 years earlier than previously thought. A paper published July 20 in the journal Nature describes dating techniques and artifact finds at Madjedbebe, a longtime site of archaeological research, that Read More ›

It ought to be so simple, right? Planet of the Apes and all that. From Colin Barras at BBC: It is true that, today, some researchers have a well-thought-through idea of what the LCA looked like and how it behaved. The trouble is that other researchers have equally well-reasoned models that suggest an LCA that looked and behaved in a completely different way. And that puts the research community in a bit of a quandary. In principle, fossilised remains of the LCA might come to light any time. They might even be discovered this very year. But because there is so little agreement on what the LCA should look like, researchers will interpret the fossils differently. “It’s a problem that Read More ›

From Dean Burnett at the Guardian: There are competing theories about this, but the point is that most other species’ young can do a lot more of the work when it comes to feeding. Human babies can latch, but not much else, so the mother has to essentially do everything. Sometimes that’s totally fine. Other times it’s like trying to insert a water balloon into a wine bottle. A soft, constantly moving, unfathomably precious wine bottle that eventually grows teeth. And the water balloon is incredibly sensitive. And you have to do this a dozen times a day. Even when you’re meant to be sleeping. It may be natural, but breastfeeding isn’t as easy a process for humans as it Read More ›

From Chase Nelson at Inference Review: The typical human gestation times of 38 weeks is, in fact, longer than one would expect for a primate of similar body mass. Instead of arguing for an enlarged brain, then, one might as easily argue for a diminished body mass. Thus, it is in spite of similar periods of gestation that humans are more helpless than other great apes at birth; humans are not born early. Moreover, we wean infants earlier than expected for a primate of our body size, not later. The opposite should be the case if weaning time is a proxy for altriciality, and if the obstetrical hypothesis is correct that altriciality requires more intelligent parents. Fetal development provides additional Read More ›

From ScienceDaily: They call their theory the “poorly sleeping grandparent hypothesis.” The basic idea is that, for much of human history, living and sleeping in mixed-age groups of people with different sleep habits helped our ancestors keep a watchful eye and make it through the night. “Any time you have a mixed-age group population, some go to bed early, some later,” Nunn said. “If you’re older you’re more of a morning lark. If you’re younger you’re more of a night owl.” The researchers hope the findings will shift our understanding of age-related sleep disorders. “A lot of older people go to doctors complaining that they wake up early and can’t get back to sleep,” Nunn said. “But maybe there’s nothing Read More ›

From David Sloan Wilson at This View of Life: Anything and Everything from an Evolutionary Perspective: ERS [Evolutionary Religious Studies] has made rapid progress during the last 20 years, in part by organizing the vast amount of empirical information on religion that has accumulated, much as Darwin was able to organize the vast amount of information on plants and animals during his day. More. It has made rapid progress if churning out a vast amount of idle naturalist speculation is progress. But remember, many of these people, deep down in their hearts, really do believe in that stuff. It would be easier to feel sympathy for them if it were not so ridiculous. See also: “The evolutionary psychologist knows why Read More ›

A comparatively sensible article from at the Genetic Literacy Project: Systemic rape used to go hand in hand with war as women, resources and lands were assimilated into the victors’ communities. The victorious men had more children, more land and more power. Some researchers have argued that this is proof of the ‘deep roots theory of war:’ Human males fight each other for reproductive advantage, proving that war is an evolutionary advantageous behavior. But this theory has been hard to prove. In fact, studies of human groups and other primates have added to the evidence both for and against the controversial idea that humans were made for war, evolutionarily speaking. A January 2015 study indicates that societies don’t actually benefit Read More ›

From Aylin Woodward at New Scientist: It’s a sex-laced mystery. If modern humans didn’t reach Europe until about 60,000 years ago, how has DNA from them turned up in a Neanderthal fossil in Germany from 124,000 years ago? The answer seems to be that there was a previous migration of early humans – more than 219,000 years ago. One that we’re only just starting to reveal from piecemeal evidence that is DNA extracted from fossilised bones.More. Note especially, “The results also suggest that Neanderthals had a much greater genetic diversity and larger population than we realised.” Indeed. A lot of speculation/discussion of Neanderthals pegs them in ways that are better described as “what we believe” than “what we know.” As Read More ›

From Nick Hughes at Aeon: We tend to treat power as though it is intrinsically valuable. We seek it out and covet it, quite irrespective of how we might wield it and what it might get us. One need only look at the history of totalitarian politics to recognise this tendency in its most grotesque form. But power isn’t intrinsically valuable, it’s only instrumentally valuable – valuable as a means to an end. And whether or not they are objectively valuable, the ends that matter to us, the things that we care about most – our relationships, our projects and goals, our shared experiences, social justice, the pursuit of knowledge, the creation and appreciation of art, music and literature, and Read More ›