Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genetic study of Neanderthal DNA reveals early split between humans and Neanderthals

16.11.2006
In the most thorough study to date of the Neanderthal genome, scientists suggest an early human-Neanderthal split. The two species have a common ancestry, say the authors, but do not share much else after evolving their separate ways. The study, published in this week's issue of Science, also finds no evidence of genetic admixture between Neanderthals and humans.

The study helps to explain the evolutionary relationship between Homo sapiens and Neanderthals (Homo neanderthalensis). It also "signifies the dawn of Neanderthal genomics," wrote the study's authors, who comprise scientists from the Lawrence Berkeley (Calif.) National Laboratory, the U.S. Department of Energy Joint Genome Institute (Walnut Creek, Calif.), the University of Chicago (Ill.) and the Max Planck Institute for Evolutionary Anthropology (Leipzig, Germany).

"Humans went through several key stages of evolution during the last 400,000 years," said study c-author Jonathan Pritchard, professor of human genetics who led the University of Chicago team that analyzed the sequencing data. "If we can compare humans and Neanderthals genomes, then we can possibly identify what the key genetic changes were during that final stage of human evolution."

Another author of the Science paper, Svante Pääbo of the Max Planck Institute, sequenced Neanderthal mitochondrial DNA in 1997 and first suggested that Neanderthals did not make a substantial contribution to the modern human gene pool. This new study, headed up by Edward Rubin of the Lawrence Berkeley National Laboratory, reinforces that long-debated theory.

"While unable to definitively conclude that interbreeding between the two species of humans did not occur," Rubin said, "analysis of the nuclear DNA from the Neanderthal suggests the low likelihood of it having occurred at any appreciable level."

According to the authors, "If Neanderthal admixture did indeed occur, then [it would] manifest in our data as an abundance of low-frequency derived alleles in Europeans where the derived allele matches Neanderthal. No site in the data set appears to be of this type."

However, Pritchard said, "We do not exclude the possibility of modest levels of genome admixture."

Pritchard's team suggests that human and Neanderthal shared a common ancestor about 706,000 years ago, and that the human and the Neanderthal ancestral populations split around 370,000 years ago. (Researchers found some genetic variation between the two species, which the team attributes to the ancestral population.) Both lines co-existed in Europe and western Asia until about 30,000 years ago.

The team used DNA extracted from a 38,000-year-old Neanderthal specimen from Vindija, Croatia. They recovered 65,250 base pairs of the Neanderthal's 3 billion total base pairs and utilized traditional sequencing technologies used for the Human Genome Project as well as the new parallel pyrosequencing method to clone and insert missing fragmented DNA and create a library of Neanderthal DNA.

Unlike the libraries used to sequence the human genome, which contained only human DNA fragments, the Neanderthal DNA library is riddled with contamination from microbes that lived off the nutrients in the Neanderthal remains, as well as contamination from humans handling the specimens.

However, the scientists performed a variety of studies to confirm that the vast majority of the human-like sequence in the library was indeed Neanderthal and not just contamination from human bone collectors and laboratory workers.

The researchers then verified the authenticity of the Neanderthal sequence by comparing it to the human and chimpanzee genomes. This revealed multiple locations where the Neanderthal sequence matched more closely to that of chimpanzee and not human. Using the comparison of the Neanderthal to the human and chimp genomes enabled the investigators to estimate the human-Neanderthal divergence timeline.

The scientists also used data from the HapMap genome project to understand the relationship between modern human diversity and the Neanderthal sequence. Their analysis showed that the Neanderthal sequence could not have come from any modern human population.

The study suggests that Neanderthal and human genomes are greater than 99.5 percent identical, which leaves less than 0.5 percent of the Neanderthal genome that will attract much attention. Many of the biological differences between modern humans and Neanderthals will be encoded at specific sites, which is why the researchers were able to analyze enough data without having to sequence the entire Neanderthal genome.

Catherine Gianaro | EurekAlert!
Further information:
http://www.uchospitals.edu

Further reports about: DNA Max Planck Institute Neanderthal sequence split

More articles from Life Sciences:

nachricht Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>