A fossil like a monkey discovered in South Africa and designed to represent a human ancestor is NOT in our direct lineage, a study finds
- New study focuses on the so-called Australopithecus sediba found near Johannesburg
- It has pelvis, face and teeth similar to humans, so many thought it was the ancestor Homo.
- It would boost the timeline of direct human descendants in 800,000 years
- A new badysis has ruled this scenario almost completely, ending the debate.
- The team concluded that the famous fossil & # 39; Lucy & # 39; remains the most likely direct ancestor
By James But for Dailymail.com
Published: 3:18 PM EDT, May 8, 2019 | Updated: 3:29 PM EDT, May 8, 2019
A scientist who is believed to be the direct ancestor of the Homo genus has been discarded by scientists who say that the statistical probability of a coincidence is "close to zero."
The badysis, published this week in Science Advances by paleontologists at the University of Chicago, focuses on a fossil named Australopithecus sediba, which was discovered inside a cave near Johannesburg eight years ago.
Due to their physical characteristics, which include a pelvis, face and teeth similar to humans, the researchers proposed that A. sediba was the direct ancestor of Homo erectus, the first of the Homo genus from which modern humans are derived.
A new study says it has ruled out a link between the fossil Australopithecus sediba and humans. Fossil molds of Australopithecus afarensis (left), Homo habilis (center) and Australopithecus sediba (right)
HOW DOES SEDIBA ADJUST TO HISTORY?
The first A. Sediba fossil was found in 2008 in a cave outside of Johannesburg.
The specimen was covered with stone. Researchers say that millions of years ago, a mother and her son fell into a fissure where they were washed by a rainstorm in a pond and immortalized in the rock.
A skeleton of A. sediba shares striking similarities with humans, including teeth, faces, and similar bony structures.
The problem, says a new study, is that it would give a date after the previous understanding of human relatives in 800,000 years.
As a result, experts say it is highly unlikely that the specimen can displace other ancestors dating back 3 million years.
The badertions were significant because of their implications in the calendar of the human race, in particular the fact that A. sediba would advance the previously understood line of direct human descendants in 800,000 years.
"What is surprising about Australopithecus sediba is that, as a field, it is a discovery we never thought would be made: a kind of transition in good faith," said Lee Berger, a paleoanthropologist at the University of the Witwatersrand in Johannesburg. of the study in 2011.
It is because of that dramatic change in the timeline that researchers say that A. sediba is probably not our direct relative.
"It's definitely possible that an ancestor's fossil is after a descendant's fossil for a long time," said the study's lead author, Andrew Du, PhD.
"We thought we would take it one step further to ask how likely it is to happen, and our models show that the probability is almost zero."
The researchers point out that the link is not entirely impossible: in the past, discoveries have restored the chronology of humans through considerable margins.
In 2017, a fossil discovery in Africa revealed that modern humans roamed the Earth some 100,000 years earlier than previously thought.
This, the researchers observe, remains drastically less than the 800,000 years projected by A. sediba.
"We see that it is possible that the fossil of an ancestor is later than that of its descendant," said Du.
"But 800,000 years is a long time."
Previous discoveries have improved the understanding of when humans roamed the Earth, going back 100,000 years. An illustration of human evolution is shown.
Instead of A. sediba, researchers say that Australopithecus afarensisis, known by the famous fossil & # 39; Lucy & # 39; discovered in 1974, it remains the most likely direct ancestor of humans.
The fossils of Lucy, as they are known, date from about 3 million years ago.
"Given the timing, geography and morphology, these three tests make us think that a crisis is a better candidate than sediba," said Zeray Alemseged, PhD, professor of Organism and Biology and Anatomy Donald M. Pritzker in UChicago.
"One can disagree about the morphology and the different characteristics of a fossil, but the level of confidence that we can place in the mathematical and statistical badyzes of the chronological data in this document makes our argument very solid".
WHEN WERE THE HUMAN ANCESTORS ANNOUNCED?
The timeline of human evolution goes back millions of years. Experts estimate that the family tree goes as such:
55 million years ago – First primitive primates evolve.
15 million years ago – Hominids (great apes) evolve from the ancestors of the gibbon.
7 million years ago – The first gorillas evolve. Later, the chimpanzee and human lineages diverge
It represents a recreation of a Neanderthal man.
5.5 million years ago – Ardipithecus, the first & # 39; protohumans & # 39; they share traits with chimpanzees and gorillas
4 million years ago – Like the first humans, the australopithecines appeared. They had brains no bigger than those of a chimpanzee, but with other more human characteristics.
3.9-2.9 million years ago – Australoipithecus afarensis lived in Africa.
2.7 million years ago – Paranthropus, lived in forests and had large jaws to chew.
2.6 million years ago – The manual axes become the first great technological innovation.
2.3 million years ago – It is believed that homo habilis appeared in Africa.
1.85 million years ago – The first hand & # 39; modern & # 39;
1.8 million years ago – Homo ergaster begins to appear in the fossil record.
800,000 years ago – The first humans control fire and create homes. The size of the brain increases rapidly
400,000 years agor – The Neanderthals begin to appear and spread throughout Europe and Asia.
300,000 to 200,000 years ago – Homo sapiens – modern humans – appear in Africa
50,000 to 40,000 years ago – Modern humans arrive in Europe.
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