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Home / Science / This is how the human element adapts to the changing world two million years ago

This is how the human element adapts to the changing world two million years ago



The sediments and stone tools of the Olduvai Canyon in Tanzania show that the versatility to help humans occupy the world appeared very early in our evolutionary history.

Olduvai provides some of the oldest tools and fossils in our genus, people. A recent study showed that environmental clues are buried in sediments. The results show that about 2 million years ago, our early relatives had the ability to adapt to the new environment.

This seems to be the key ability for our relatives to go to the world.By 1

.7 million years ago, an early human relative Standing person It has spread beyond Africa and throughout most of Asia, even to Indonesia. They had arrived in Western Europe 1.2 million years ago. During travel, the environment that humans encounter is completely different from that experienced by their ancestors, such as the tropical forests of Indonesia and the dry grasslands of Central Asia.

They may only need to leave themselves in one place in Africa to prepare for this. At the recently excavated site Ewass Oldupa on the edge of the famous Olduvai Gorge, research results show that early orangutans lived in a constantly changing landscape.

Life after the volcano

The oldest evidence of the earliest human relatives that we have in Olduvai Gorge is a few stone tools made and used about 2.03 million years ago.

Like other tools unearthed by Ewass Oldupa, they are also part of the Olduwan complex: relatively simple stone tools made by early portraits, such as Upright H. with Habis. Olduwan tools are mostly sharp slices and are very basic tools for shredding, scraping and pounding. They were much more complicated and precise than tools made by later Neanderthals, who chopped up small slices with a carefully prepared stone core. But for hundreds of thousands of years, the crude and ready Olduwan tools have done the job.

In Ewass Oldupa, the job is to survive on a fern-like meadow, where several grasses and woody plants are scattered, and the meandering river waters. The ferns may be the first plants to take root on pumice stones ejected from a nearby volcano not long ago. Traces of this landscape are still buried in the sediments about one meter above the rocky remains of the ancient pyroclastic flow. Paleoanthropologist Michael Petraglia of the Max Planck Institute for Human History Sciences and his colleagues discovered pollen fossils and tiny fossilized plant tissues in this layer, called the plant stone layer , There are 10 stone tools.

For those who like hunting HabisThe fossil site there is only a few hundred meters from Ewass Oldupa, so this fern basin was originally a good place to make a living.

The river provides convenient access to water, and the geological conditions in the area provide multiple sources of stone for the tools. Geochemical analysis of the tools in Ewass Oldupa revealed that the race here collected some quartzite locally, while the rest ventured to 12 kilometers (7.5 miles) away. They seem to have chosen different materials (specific in some cases, such as choosing slightly different types of quartzite from different outcrops) for specific tools. (A study last year also showed that the earliest tool makers in our family tree knew enough to choose materials wisely.)

But then everything will change.

A new world in the same place

Thousands of years later, people who once foraged on the banks of the river could not recognize the scenery around Ewass Oldupa. The grass of bracken has given way to a piece of woods and grass around the lake shore. The microscopic fossils captured in the sediments indicate that the types of plants that make up these forests and grasslands frequently change, while the deposition of charcoal indicates that wildfires periodically sweep the area, rearranging the patchy landscape.

During the long prehistoric period of the region, the lake expanded, and the muddy deposits on the shore made the forest and palm groves lush. Later, the shore of the lake gave way to a dry grassland with almost no trees and grass. Each of these environments offers very different food, water, supplies, and challenges, but ginseng seems to have been returning to Ewass Oldupa.

“Over time, these habitats sometimes change slowly or quickly,” Petraglia told Ars. “Due to the resolution of records, it is difficult to know how humans quickly enter the new ecosystem, but it is clear that they can cope with a variety of environments.”

Petraglia and his colleagues discovered stone tools (probably Habis) Constantly changing in its 200,000 years of constant change. 565 stone tools are scattered in the layered sediments of the site for thousands of years and do not look like the remains of a permanent settlement. Instead, it may be due to sudden environmental changes or volcanic eruptions that races leave the basin many times, but they keep returning.

Petraglia told Ars: “In the time frame of 235,000 years, there have been many volcanic events in Ewass Oldupa,” “Interestingly, after each eruption, the Terrans returned to these Region, that is, they never completely abandoned the region.”

Know everything

Even if the earliest hunters and gatherers of Ewass Oldupa would find later versions of the place completely unfamiliar, they would still recognize the tools people used to survive. For about 200,000 years, anthropologists have relied on the same basic tools to deal with fern grasslands by rivers, the woods and grasses are scattered, and the lake shores are dense and dry grasslands.

Olduwan’s shredding, scraping and percussion tools are relatively simple, but they are also very versatile. According to Petraglia and colleagues, Olduwan technology provides a basic universal toolkit that is as effective in palm trees by the lake as on dry grasslands. The reason why humans occupy the world is because we are generalists, who can adapt to almost anything. Our early relatives obviously have the same advantage.

Nature Communications, 2020 DOI: 10.1038 / s41467-020-20176 (about DOI).


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