Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Scientists reshape Y chromosome haplogroup tree gaining new insights into human ancestry

The Y chromosome retains a remarkable record of human ancestry, since it is passed directly from father to son.

In an article published online today in Genome Research (, scientists have utilized recently described genetic variations on the part of the Y chromosome that does not undergo recombination to significantly update and refine the Y chromosome haplogroup tree. The print version of this work will appear in the May issue of Genome Research, accompanied by a special poster of the new tree.

Human cells contain 23 pairs of chromosomes: 22 pairs of autosomes, and one pair of sex chromosomes. Females carry a pair of X chromosomes that can swap, or recombine, similar regions of DNA during meiosis. However, males harbor one X chromosome and one Y chromosome, and significant recombination between these dissimilar sex chromosomes does not occur. Therefore, the non-recombining region of the Y chromosome (NRY) remains largely unchanged over many generations, directly passed from father to son, son to grandson, and so on, along with genetic variations in the NRY that may be present. Scientists can use genetic variations, such as single nucleotide polymorphisms (SNPs), on the Y chromosome as markers of human ancestry and migration.

In 2002, the Y Chromosome Consortium (YCC) constructed a tree of 153 haplogroups based upon 243 unique genetic markers. In this report, researchers led by Dr. Michael Hammer of the University of Arizona recognized the need to revisit the Y chromosome haplogroup tree and incorporate the latest data. “The YCC effort in 2002 was a landmark in mapping the then known 300 or so Y-linked SNPs on a single tree, and getting the community to use the same nomenclature system,” explains Hammer. “The rate of SNP discovery has continued to increase over the last several years, as are publications on Y chromosome origins and affinities. While this new information is useful, ironically it also brings with it the danger of introducing more chaos into the field.”

Hammer’s group integrated more than 300 new markers into the tree, which allowed the resolution of many features that were not yet discernable, as well as the revision of previous arrangements. “The major lineages within the most common African haplogroup, E, are now all sorted out, with the topology providing new interpretations on the geographical origin of ancient sub-clades,” describes Hammer. “When one polymorphism formerly described as unique, but recently shown to have reversed was replaced by recently reported markers, a sub-haplogroup of haplogroup O, the most common in China, was considerably rearranged,” explains Fernando Mendez, a co-author of the study.

In addition to improving the resolution of branches, the latest reconstruction of the tree allows estimates of time to the most recent common ancestor of several haplogroups. “The age of [haplogroup] DE is about 65,000 years, just a bit younger than the other major lineage to leave Africa, which is assumed to be about 70,000 years old,” says Hammer, describing an example of the fine resolution of age that is now possible. “Haplogroup E is older than previously estimated, originating approximately 50,000 years ago.”

Furthermore, Hammer explains that this work has resulted in the addition of two new major haplogroups, S and T, with novel insights into the ancestry of both. “Haplogroup T, the clade that Thomas Jefferson’s Y chromosome belongs to, has a Middle Eastern affinity, while haplogroup S is found in Indonesia and Oceania.”

“More SNPs are being discovered, and we anticipate the rate to increase with the 1000 Genomes Project,” says Hammer, referring to the wealth of human genetic variation data that will soon be available. While this report represents a significant advance in mapping ancestry by Y chromosome polymorphisms, it is certain that future discoveries will necessitate continual revisions to the Y chromosome haplogroup tree, helping to further elucidate the mystery of our origins.

Peggy Calicchia | EurekAlert!
Further information:

Further reports about: Chromosome Genom Human Polymorphism SNP ancestry genetic variation haplogroup

More articles from Life Sciences:

nachricht ‘Farming’ bacteria to boost growth in the oceans
24.10.2016 | Max-Planck-Institut für marine Mikrobiologie

nachricht Calcium Induces Chronic Lung Infections
24.10.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

All Focus news of the innovation-report >>>



Event News

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

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Oasis of life in the ice-covered central Arctic

24.10.2016 | Earth Sciences

‘Farming’ bacteria to boost growth in the oceans

24.10.2016 | Life Sciences

Light-driven atomic rotations excite magnetic waves

24.10.2016 | Physics and Astronomy

More VideoLinks >>>