Human Evolution

[Jo Bowyer]

Language is Learned in Brain Circuits that Predate Humans

http://neurosciencenews.com/language...circuits-8398/

[Jo Bowyer]

These mysterious stone blades point to early human toolmaking in India

http://www.sciencemag.org/news/2018/...et_cid=1827845

[Jo Bowyer]

Could these be the oldest Neandertal tools made with fire?

http://www.sciencemag.org/news/2018/...et_cid=1834904

FigS5_thumb.jpg?itok=ic05FMBC.jpg

[Jo Bowyer]

The genome of Cheddar Man, who lived 10,000 years ago, suggests that he had blue eyes, dark skin and dark curly hair

https://www.theguardian.com/science/...alysis-reveals

Britain was periodically settled and then cleared during ice ages until the end of the last glacial period about 11,700 years ago, since when it has been continuously inhabited.

Until now, though, it hasn’t been clear whether each wave of migrants was seeded from the same population in mainland Europe; the latest results suggest this was not the case.

The team homed in on genes known to be linked to skin colour, hair colour and texture, and eye colour. For skin tone, there are a handful of genetic variants linked to reduced pigmentation, including some that are very widespread in European populations today. However, Cheddar Man had “ancestral” versions of all these genes, strongly suggesting he would have had “dark to black” skin tone, but combined with blue eyes.

Scientists believe that populations living in Europe became lighter-skinned over time because pale skin absorbs more sunlight, which is required to produce enough vitamin D. The latest findings suggest pale skin may have emerged later, possibly when the advent of farming meant people were obtaining less vitamin D though dietary sources like oily fish.

Cheddar Man would have lived a hunter-gatherer lifestyle, making sharp blades from flints for butchering animals, using antlers to whittle harpoons for spear fishing and carving bows and arrows.

[Jo Bowyer]

‘Walking’ fish help scientists to understand how we left the ocean

https://theconversation.com/walking-...%20the%20ocean

[Jo Bowyer]

Modern Human Brain Organization Emerged Only Recently

http://neurosciencenews.com/evolutio...nization-8386/

The evolutionary history of our own species can be traced back to fossils from Jebel Irhoud (Morocco) dated to about 300,000 years ago. Last year’s analysis of these fossils by researchers from the Department of Human Evolution at the Max Planck Institute for Evolutionary Anthropology in Leipzig was highlighted as one of the top science stories of 2017 by a diverse range of print and online media. Together with crania from Florisbad (South Africa, 260,000 years old), and Omo Kibish (Ethiopia) dated to 195,000 years ago, the Jebel Irhoud fossils document an early evolutionary phase of Homo sapiens on the African continent. Their face and teeth look modern, however their elongated braincase appears more archaic as in older human species and in Neandertals. In contrast, it is a globular braincase, which characterizes the skull of present-day modern humans together with small and gracile faces.

In a new paper published in Science Advances, members of the same research team now reveal additional surprising findings about brain evolution in Homo sapiens. The paleoanthropologists Simon Neubauer, Jean-Jacques Hublin and Philipp Gunz used micro computed tomography scans to create virtual imprints of the internal bony braincase, so called endocasts that approximate brain size and shape. They used state-of-art statistics to analyze endocasts of various fossils and present-day humans.

Evolution of the parietal lobe and the cerebellum

Neubauer and colleagues document a gradual change within Homo sapiens, from an elongated endocranial shape towards a more globular one. Two features of this process stand out: parietal and cerebellar bulging. Parietal brain areas are involved in orientation, attention, perception of stimuli, sensorimotor transformations underlying planning, visuospatial integration, imagery, self-awareness, working and long-term memory, numerical processing, and tool use. The cerebellum is not only associated with motor-related functions like the coordination of movements and balance, but also with spatial processing, working memory, language, social cognition, and affective processing.

The Homo sapiens fossils were found to have increasingly more modern endocranial shapes in accordance with their geological age. Only fossils younger than 35,000 years show the same globular shape as present-day humans, suggesting that modern brain organization evolved some time between 100,000 and 35,000 years ago. Importantly, these shape changes evolved independently of brain size — with endocranial volumes of around 1,400 milliliters, even the oldest Homo sapiens fossils from Jebel Irhoud fell within present-day variation of brain size. “The brain is arguably the most important organ for the abilities that make us human,” says Neubauer. But modern human brain shape was not established at the origin of our species together with other key features of craniodental morphology. Neubauer adds: “We already knew that brain shape must have evolved within our own species, but we were surprised to discover just how recent these changes to brain organization were.”

[Jo Bowyer]

Children aren’t starting puberty younger, medieval skeletons reveal

https://theconversation.com/children...etons%20reveal

Factors such as poverty, poor nutrition, alcohol consumption, air pollution, violence and neglect delay menarche as malnutrition and physical stress limit the body’s ability to sustain a pregnancy. These severe environmental conditions were likely to have been experienced by all teenagers living and working in medieval England.

Many children experienced strenuous physical labour and exposure to urban pollution. Others suffered from chronic diseases such a tuberculosis, leprosy and syphilis. But it was medieval London that provided the greatest challenges. Here menarche was not reached by girls until two years after their peers living in other urban areas.

The picture from medieval England demonstrates the impact of poor environmental conditions on the tempo of puberty and the start of menarche. But despite these hardships, the more subtle changes signalling the onset of puberty remained the same, at around ten years. While data is more limited, evidence from Roman Britain and medieval Spain show the same age for the onset of puberty at ten to 12 years.

[Jo Bowyer]

What ancient footprints can tell us about what it was like to be a child in prehistoric times

https://theconversation.com/what-anc...storic%20times

The findings create a unique and momentary insight into the world of a child long ago. They clearly were not left at home with a babysitter when the parents were hunting. In the harsh savannah plains of the East African Rift Valley, it was natural to bring your children to such daily tasks, perhaps so they could observe and learn.

[Jo Bowyer]

Will human influences on evolutionary dynamics in the wild pervade the Anthropocene?


https://bmcbiol.biomedcentral.com/ar...915-017-0476-1


Abstract

The five most pervasive anthropogenic threats to biodiversity are over-exploitation, habitat changes, climate change, invasive species, and pollution. Since all of these threats can affect intraspecific biodiversity—including genetic variation within populations—humans have the potential to induce contemporary microevolution in wild populations. We highlight recent empirical studies that have explored the effects of these anthropogenic threats to intraspecific biodiversity in the wild. We conclude that it is critical that we move towards a predictive framework that integrates a better understanding of contemporary microevolution to multiple threats to forecast the fate of natural populations in a changing world.

[Jo Bowyer]

Anthropocene began in 1965, according to signs left in the world’s ‘loneliest tree’

https://theconversation.com/anthropo...neliest%20tree

On Campbell Island in the Southern Ocean, some 400 miles south of New Zealand, is a single Sitka spruce. More than 170 miles from any other tree, it is often credited as the “world’s loneliest tree”. Planted in the early 20th century by Lord Ranfurly, governor of New Zealand, the tree’s wood has recorded the radiocarbon produced by above ground atomic bomb tests – and its annual layers show a peak in 1965, just after the tests were banned. The tree therefore gives us a potential marker for the start of the Anthropocene.

But why 1965? The 1960s is a decade forever associated with the hippie movement and the birth of the modern environmentalism, a sun-blushed age in which the Apollo moon landings gave us the iconic image of a fragile planet framed against a desolate lunar surface. It was also a time when the world was fast globalising, with rapid industrialisation and economic growth driving population expansion and a massive increase in our impact on the environment.

This postwar period has been called the “Great Acceleration”. So the question we’re interested in is whether this step change in human activity left an indelible mark on our planet, one which, if we disappeared today, would still leave a permanent signature in the geological record.

[Jo Bowyer]

Did Homo erectus speak?

https://aeon.co/essays/tools-and-voy...18a33-69418129

Evidence that erectus had language comes from their settlements, their art, their symbols, their sailing ability and their tools. Erectus settlements are found throughout most of the old world. And, most importantly for the idea that erectus had language, open oceans were not barriers to their travel.

[Jo Bowyer]

Human ancestors had the same dental problems as us – even without fizzy drinks and sweets

https://theconversation.com/human-an...20and%20sweets

[Jo Bowyer]

How ancient humans survived global ‘volcanic winter’ from massive eruption

http://www.sciencemag.org/news/2018/...et_cid=1903121

[Jo Bowyer]

Calculated or caring? Neanderthal healthcare in social context


https://www.tandfonline.com/doi/full...3.2018.1433060


ABSTRACT

Explanations for patterns of healed trauma in Neanderthals have been a matter of debate for several decades. Despite widespread evidence for recovery from injuries or survival despite impairments, apparent evidence for healthcare is given limited attention. Moreover, interpretations of Neanderthals’ approach to injury and suffering sometimes assume a calculated or indifferent attitude to others. Here the authors review evidence for Neanderthal healthcare, drawing on a bioarchaeology of care approach and relating healthcare to other realms of Neanderthal social life. The authors argue that Neanderthal medical treatment and healthcare was widespread and part of a social context of strong pro-social bonds which was not distinctively different from healthcare seen in later contexts. They suggest that the time has come to accept Neanderthal healthcare as a compassionate and knowledgeable response to injury and illness, and to turn to other questions, such as cultural variation or the wider significance of healthcare in an evolutionary context.

[Jo Bowyer]

Complex behavior arose at dawn of humans

http://science.sciencemag.org/conten...6381/1200.full

More than 320,000 years ago in the Rift Valley of Africa, some early innovators adopted a new technology: They eschewed the clunky, palm-size stone hand axes that their ancestors had used for more than a million years in favor of a sleek new toolkit. Like new generations of cellphones today, their Middle Stone Age (MSA) blades and points were smaller and more precise than the old so-called Acheulean hand axes and scrapers.

These toolmakers in the Olorgesailie Basin in Kenya chose as raw materials shiny black obsidian and white and green chert, rocks they had to get from distant sources or through trade networks. In another first, they chiseled red and black rocks, probably to use as crayons to color their bodies or spears—an early sign of symbolic behavior. “This is indicative of a gear change in behavior, toolmaking, and material culture,” says evolutionary psychologist Robin Dunbar at the University of Oxford in the United Kingdom, who studies social networks.

This resonates, I have seen many changes in behaviour, tool making and culture, since I started.Some things don't change though, when computers took up most of the room in which they were housed, students were infecting them with viruses and complaining that their victims had no sense of humour.