Aboriginal Australians, Pacific Islanders carry DNA of unknown human species, research analysis suggests

Date:

Share post:

People from Papua New Guinea and north-east Australia carry small amounts of DNA of an unidentified, extinct human species, a new research analysis has suggested.

Aboriginal Australians, Pacific Islanders carry DNA of unknown human species, research analysis suggests
A third group of hominids may have bred with the ancestors of Melanesians [Credit: Briar March/ABC]

The analysis suggests the DNA is unlikely to come from Neanderthals or Denisovans, but from a third extinct hominid, previously unknown to archaeologists.

Statistical geneticist Ryan Bohlender and his team investigated the percentages of extinct hominid DNA in modern humans.

They found discrepancies in previous analyses and found that interbreeding between Neanderthals and Denisovans was not the whole story to our ancestors’ genetic makeup.

Mr Bohlender presented his analysis to the American Society of Human Genetics in Canada, saying that scientists were either “missing a population” or “misunderstanding something about the relationships”.

What does the discovery mean?

Mr Bohlender and his colleague used a computer model to figure out the amount of Neanderthal and Denisovan DNA carried by modern humans.

They found Europeans and Chinese people carry about 2.8 per cent of Neanderthal DNA.

But Europeans have no Denisovan ancestry, and Chinese people only have 0.1 per cent.

Modern populations from South Pacific regions including Vanuatu, the Solomon Islands, Fiji, Papua New Guinea, New Caledonia, West Papua, and the Maluku Islands have 2.74 per cent of their DNA as coming from Neanderthals.

Mr Bohlender estimates the amount of Denisovan DNA in these people is as low as about 1.11 per cent, not the 3 to 6 per cent estimated by other researchers.

Therefore, Mr Bohlender and his colleagues came to the conclusion that a third group of hominids may have bred with the ancestors of Melanesians.

“The sequencing of complete Neanderthal and Denisovan genomes has provided several insights into human history,” Mr Bohlender said.

“One important insight stems from the observation that modern non-Africans and archaic populations share more derived alleles than they should if there was no admixture between them.

“We now know that the ancestors of modern non-Africans met, and introgressed with, Neanderthals and Denisovans.”

Neanderthal, Denisovan — what’s the difference?

Neanderthals and Denisovans are two hominid species that migrated out of Africa.

According to theory, Neanderthals left Africa about 300,000 years ago, settling in Europe and parts of western Asia.

The Denisovan species was only discovered in 2008 when paleoanthropologists discovered a 40,0000-year-old tooth and pinkie bone from a young girl in a Siberian cave.

Scientists examined the DNA from the bone and found that, although the girl was closely related to Neanderthals, it was distinct enough to merit classification as a new species.

There was a genetic overlap between the Denisovan genome and that of some present-day east Asians, and a group of Pacific Islanders living in Papua New Guinea.

This is why the discovery of a possible third hominid species is a remarkable discovery, especially considering the discovery was made from DNA of modern people.

Unidentified species flagged in Aboriginal Australian DNA

Mr Bohlender’s findings are supported by an earlier study from the University of Cambridge which sequenced the genome of 83 Aboriginal Australians from the Pama-Nyungan-speaking language group, which covers 90 per cent of the continent, and 25 Highland Papuans.

It revealed Papuan and Aboriginal ancestors left Africa around 72,000 years ago and then split from the main group around 58,000 years ago.

They reached the supercontinent of ‘Sahul’ that originally united Tasmania, mainland Australia and New Guinea around 50,000 years ago, picking up the DNA of Neanderthals, Denisovans and another extinct hominin along the way.

See also: Denisovan DNA excavated in modern Pacific Islanders

Source: ABC News Website [October 31, 2016]

ADVERTISEMENT

spot_img

Related articles

Ptolemaic tombs uncovered in Egypt’s Minya

During excavation work carried out at Al-Kamin Al-Sahrawi area, south east of Samalout Town in Al-Menia Governorate, an...

Taking the temperature of the Universe

Astronomers using a CSIRO radio telescope have taken the Universe's temperature, and have found that it has cooled...

Hubble spots a colourful lenticular galaxy

The NASA/ESA Hubble Space Telescope has captured a beautiful galaxy that, with its reddish and yellow central area,...

Nature uses Screws and Nuts

A musculoskeletal system so far unknown in the animal world was recently discovered in weevils. The hip of...

New jawless fish found from the Lower Devonian of Yunnan, China

The Galeaspida is a clade of armored jawless vertebrates. Most galeaspids have a strongly flattened head-shield, dorsally set...

World’s smallest temple discovered in Damagou, China

Wooden tablets aren’t the only priceless treasures to dot this desert oasis. Temple One of the Toop Baruch...

Greek Monuments still have no voice after video banned

The Association of Greek Archaeologists (SEA) launched a campaign in March this year, an international appeal for the...

Egyptian Museum says eighteen items missing after unrest

A full inventory of the Egyptian Museum has found that looters escaped with 18 items during the anti-government...