Human Evolution

human evolution

Hard-knock hominid skeletons tell harsh tales

The Pleistocene was a hard time for hominids. Homo fossils from this period, when humans evolved and expanded from Africa and across Eurasia, are riddled with an unusual number of skeletal abnormalities. Swollen braincases, bowed femurs, twisted long bones, pronounced dwarfism and malformed teeth are just a few of the unusual skeletal features found in many Pleistocene hominid fossils. A new statistical study has confirmed that these anomalies occur at higher-than-expected rates in the Pleistocene fossil record. But whether this elevated incidence was mainly caused by nutritional stress or inbreeding, or if it’s an artifact of preservational bias, is unknown.

15 Mar 2019

"Cradle of Humankind" fossils can now be dated

Robyn Pickering was taught as an undergraduate about a collection of limestone caves in northern South Africa known collectively as the Cradle of Humankind for the trove of early hominin fossils discovered there. She learned that, unlike hominin fossils unearthed in East Africa, whose ages have been constrained by dating the surrounding layers of volcanic ash, the fossils in the Cradle — including well-preserved specimens of Australopithecus africanus and the recently discovered Homo naledi, among others — were impossible to date independently. Now, Pickering, an isotope geochemist at the University of Cape Town, and her colleagues have figured out a way to date the South African fossils after all. In a recent study published in Nature, the researchers report ages for flowstones — horizontal deposits of calcium carbonate that form natural cements on cave floors — across eight caves in the Cradle of Humankind. The flowstones sandwich fossil-bearing sediment layers, allowing age ranges for the fossils to be determined.

05 Feb 2019

Climate cooling a driver of Neanderthals' extinction

Neanderthals disappeared from Europe roughly 40,000 years ago, and scientists are still trying to figure out why. Did disease, climate change or competition with modern humans — or maybe a combination of all three — do them in? In a recent study, researchers offer new evidence from Eastern Europe that climate change was a major player in the Neanderthals’ disappearance.

30 Nov 2018

Speartips point at south-to-north Clovis dispersal

During the last ice age, long before people first entered North America, much of the Canadian and American Rockies were buried under massive ice sheets. As the ice age waned about 13,000 years ago, an ice-free corridor 1,500-kilometers long and several hundred kilometers wide opened east of the Rocky Mountains.

02 Aug 2018

Trio of studies track stone tool technology in Kenya

About 300,000 years ago, East Africa was a hotbed of human evolution and innovation. Sweeping ecological changes contributed to the emergence of modern humans, and spurred the first long-distance trade routes and novel toolmaking technologies. Three new studies published in Science shine a spotlight on Kenya’s Olorgesailie Basin, where the clunkier Acheulean tool technology gave way to the smaller, sleeker Middle Stone Age tool technology famously associated with Homo sapiens.

05 Jul 2018

Weedy seeds gathered in once-green Sahara

Today, the vast and arid Sahara Desert seems an unlikely place to find early signs of seed gathering and plant cultivation in Africa, but new evidence shows that, 10,000 years ago, people were collecting, sorting and saving seeds near a rock shelter known as Takarkori.

28 Jun 2018

Oldest human remains outside Africa found in Israel

The recent discovery of a jawbone belonging to Homo sapiens, and associated stone tools, in Israel may push back the timing of the earliest human migration out of Africa by as much as 50,000 years.

28 May 2018

A new look at Cheddar Man

In 1903, a skeleton was found in a limestone cave in Cheddar Gorge, near Somerset, England. Radiocarbon dating in the 1970s revealed the remains to be more than 10,000 years old, making it the oldest near-complete human skeleton found in Britain. Now, as yet unpublished research suggests Cheddar Man’s genome reveals a surprisingly different appearance for the Mesolithic man from what’s long been thought, according to researchers who analyzed DNA from the skeleton.

23 May 2018

Drought drove early humans from Africa

Genetics studies have dated the largest migrations of early Homo sapiens out of Africa to between 70,000 and 55,000 years ago, although smaller groups may have left earlier. The most widely accepted exodus theory, known as the “green carpet” or “green Sahara” hypothesis, holds that people likely left during wetter periods in the Sahara and Arabia, which would have allowed easier passage into Eurasia via the Middle East. But new research supports the opposite idea: that drier conditions may have triggered at least some of the exodus.

28 Feb 2018

Nothing is clear about who left marks on ancient bones

An ongoing debate regarding the origin of scrape marks on ancient animal bones has taken a new turn. The marks were first thought to have been made by early hominid butchers, then by trampling, and now it’s looking like crocodiles might have been responsible, according to a recent study in Proceedings of the National Academy of Sciences (PNAS).

05 Jan 2018