Monthly Archives: May 2017

When fossil hunters unveiled the remains of a mysterious and archaic new species of human found deep inside a cave in South Africa two years ago, the scientific community was stunned. Since then, bodies of the long-lost family members have piled up.

In work published on Tuesday in the journal eLife, the team reveals how high that pile has become. They now have the remnants of at least 18 Homo naledi, as the species is named. The most recent haul of bones, found in a cave chamber 100 metres from the first, includes a nearly complete adult skull.

Tests on the material found the bones to be between 335,000 and 236,000 years old, making them far younger than many scientists had expected. It means that this species of primitive hominid was actually around at the same time as Homo sapiens, said Lee Berger, the lead scientist at the University of Witwatersrand in Johannesburg.

The bones, remarkably, show few signs of disease or stress from poor development, suggesting that Homo naledi may have been the dominant species in the area at the time. They are the healthiest dead things youll ever see, said Berger.

Homo naledi stood about 150cm tall fully grown and weighed about 45kg. But it is extraordinary for its mixture of ancient and modern features. It has a small brain and curved fingers that are well-adapted for climbing, but the wrists, hands, legs and feet are more like those found on Neanderthals or modern humans. If the dating is accurate, Homo naledi may have emerged in Africa about two million years ago but held on to some of its more ancient features even as modern humans evolved.

This is astonishingly young for a species that still displays primitive characteristics found in fossils about two million years old, said Chris Stringer at the Natural History Museum in London, who was not involved in the research.

The age of the bones, and their discovery in the Rising Star cave system on the edge of the Cradle of Humankind World Heritage site near Johannesburg, has led Berger to speculate that some ancient stone tools found in the region might have wrongly been attributed to Homo sapiens. Instead, they might be the work of Homo naledi, he said.

No stone tools have ever been found with Homo naledi bones, but Stringer does not rule out the possibility that the species may have made them. It seems highly likely that its handiwork is present in the archaeological record of southern Africa, but currently unattributed, he said.

Another question raised by the remains is how they got to their final resting place. Berger does not believe that the creatures got there by accident. I think the discovery of this second chamber adds to the idea that Homo naledi deliberately disposed of its dead in the deep underground chambers in the Rising Star cave system, he said. I cant see any other way, other than them going into these remote chambers themselves and bringing bodies in. To do that, he suspects, they were also able to control fire.

Others are not so confident. Stringer said he and many other experts doubted that Homo naledi, with a brain the size of a gorillas, was capable of such complex behaviour. Perhaps further exploration will reveal other, closer, entrances or sinkholes which were temporarily open, through which the remains could have been introduced by accidental or natural processes? he said.

According to Jessica Thompson, a palaeolithic archaeologist at Emory University in Atlanta, what the bones do make clear is that human evolution was not the straightforward, linear progression from one species to another that it is often made out to have been. It doesnt start out with something that looks like a monkey, and the something that looks like an ape, and then something that looks like a human, and then all of the sudden youve got people, she said. Its much more complicated than that.

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New haul of Homo naledi bones sheds surprising light on human evolution - The Guardian

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Understanding evolution is one of the cornerstones of biology evolution is, in fact, the sole explanation for lifes diversity on our planet. Based on the evolution of proteins, researchers may explain the emergence of new species and functions through genetic changes or how enzymes with novel functions might be engineered.

One popular approach to the study of evolution is to compare genome data using bioinformatics tools. Scientists using these approaches may compare specific proteins, which consist of combinations of 20 universal building blocks, called amino acids.

So far, the bioinformatics tools used to study the evolution of single proteins have assumed that the speed at which different regions of proteins evolve can be modelled with a statistical distribution whose shape is determined by a single variable.

That assumption, however, does not reflect reality, and it might have led to a large proportion of biased phylogenetic results being published over the last two decades or so, explains Minh Quang Bui, from the Center for Integrative Bioinformatics (CIBIV).

Arndt von Haeseler, group leader at the Max F Perutz Laboratories (MFPL) and Lars Jermiin from the Australian National University have now found a revolutionary way of implementing different rates of evolution into bioinformatics models.

It was well known among experts that the popular approach might not capture the complexities of protein evolution. However, the computational cost of using more realistic models was unacceptably high.

We have now developed a fast algorithm that gives us previously unavailable insights into protein evolution the new tool is likely to have a huge impact on a wide variety of research areas, including on the evolution of pathogens and the dispersal of agricultural pests, adds Lars Jermiin.

The new program ModelFinder will allow more accurate scientific estimates of evolutionary processes. This enhanced understanding of evolution will help us come one step closer to unravelling the mysteries, which are responsible for the great diversity on our planet.

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A new bioinformatics tool to decipher evolutionary biology - Drug Target Review

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The Evolution of Beauty: How Darwins Forgotten Theory of Mate Choice Shapes the Animal World and Us

Richard O. Prum, the William Robertson Coe Professor of Ecology and Evolutionary Biology and professor of forestry and environmental studies

(Doubleday)

In the great halls of science, dogma holds that Darwins theory of natural selection explains every branch on the tree of life: which species thrive, which wither away to extinction, and what features each evolves. But, Richard Prum asks, can adaptation by natural selection really account for everything we see in nature?

Prum reviving Darwins own views thinks not. Deep in tropical jungles around the world are birds with an array of appearances and mating displays: Club-winged Manakins who sing with their wings, Great Argus Pheasants who dazzle prospective mates with a four-foot-wide cone of feathers covered in golden 3D spheres, Red-capped Manakins who moonwalk. In 30 years of fieldwork, Prum has seen numerous display traits that seem disconnected from, if not contrary to, selection for individual survival. To explain this, he dusts off Darwins long-neglected theory of sexual selection in which the act of choosing a mate for purely aesthetic reasons for the mere pleasure of it is an independent engine of evolutionary change.

Mate choice can drive ornamental traits from the constraints of adaptive evolution, allowing them to grow ever more elaborate. It also sets the stakes for sexual conflict, in which the sexual autonomy of the female evolves in response to male sexual control. Most crucially, this framework provides important insights into the evolution of human sexuality, particularly the ways in which female preferences have changed male bodies, and even maleness itself, through evolutionary time.

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Book: The Evolution of Beauty - Yale News