Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

It’s complicated - new insights into the evolutionary history of bears

11.06.2014

According to researchers of the LOEWE Biodiversity and Climate Research Centre (BiK-F), Goethe University Frankfurt and the U.S. Wildlife Service several bear species that today only occur in America or in Asia have hybridized in their evolutionary history. The Beringia land bridge, which in former times connected the habitats of these species, might have enabled their encounter. The large-scale study is based on the comparison and analysis of genetic material of all bear species that still exist. The results have been published recently in the journal Evolution and Molecular Biology.


American black bear. Copyright: Tobias Bidon

If in documentaries or in the zoo - everyone has seen and knows about brown bears, polar bears and pandas. However, there are several other bear species in Asia and South America that are less well-known, such as the sloth bear, the Asiatic or the spectacled bear. There are eight bear species that still exist worldwide. Despite many years of research, the exact relationships between them remain unresolved.

Who with whom? Polar bear and brown have hybridized
Previous analyses of genetic material of polar bears and brown bears have proven already that the two species have hybridized during their long evolutionary history. This behavior can still be observed today and the ongoing climate change drives the bear even closer. It is therefore likely that there have been similar exchanges of genetic material between other species of the bear family.

... as well as brown bears and black bears
To shed light on this, a team of the German Biodiversity and Climate Research Centre (BiK-F) and the Goethe University Frankfurt in cooperation with colleagues from the US have now analyzed certain genome parts of all bear species alive today. "We were able to show that several bear species have hybridized during their evolutionary history. The exchange can still be traced in the genetic makeup of today's bears," says the lead author of the study, Verena Kutschera (BiK-F). This mix-up makes it difficult to classify some gene fragments as belonging to a particular species.

Beringia land bridge serving as an intercontinental meeting point
Surprisingly, several bear species which nowadays live on different continents have also taken part in the mating and thus gene exchange. This may have been possible because the significantly lower sea level during past ice ages resulted in a land bridge between Asia and North America, the Beringia land bridge. Thus the ancestors of today’s bear species, e.g. of the Asiatic black bear and the American black bear, had the opportunity to meet and to mate.

Darwin’s species tree is insufficient to map complicated relationships
All eight bear species that occur today have well adapted to their present habi-tat and differ physically very much. A prime example for this is polar bears and black bears. Nevertheless, the speciation of some individual genes has not finished yet which additionally complicates the research of the evolution of bears.

With new molecular methods more gene parts might be discovered in the genomes of mammal species that could originate from other species. Apparently separate genetic lineages turn out to have merged – sometimes repeatedly – during the evolutionary history and exchanged genetic material with each other. "The traditional pedigree already used by Darwin is not always suitable to map evolutionary history in full detail. So-called phylogenetic networks a more useful to depict the genetic mix-up that we have found ", comments evolutionary biologist Prof. Dr. Axel Janke, BiK-F, leader of the research team. The study demonstrates that evolution often is not a linear process; thanks to modern molecular methods it’s complex processes are finally revealed.

Publication:
Kutschera, V. et al. Bears in a forest of gene trees: Phylogenetic inference is complicated by incomplete lineage sorting and gene flow – Molecular Biology and Evolution, DOI: 10.1093/molbev/msu186


For further information please contact:

Prof. Dr. Axel Janke
LOEWE Biodiversity and Climate Research Centre (BiK-F)
Tel. +49 (0)69 7542 1842
axel.janke@senckenberg.de

or
Verena Kutschera
LOEWE Biodiversity and Climate Research Centre (BiK-F)
Tel. +49 (0)69 7542 1828
verena.kutschera@senckenberg.de

or
Sabine Wendler
LOEWE Biodiversity and Climate Research Centre (BiK-F)
Press officer
Tel. +49 (0)69 7542 1838
Sabine.wendler@senckenberg.de

 
LOEWE Biodiversität und Klima Forschungszentrum, Frankfurt am Main
With the objective of analysis the complex interactions between biodiversity and climate through a wide range of methods, the Biodiversität und Klima Forschungszentrum [Biodiversity and Climate Research Centre] (BiK‐F) has been funded since 2008 within the context of the Landes‐ Offensive zur Entwicklung Wissenschaftlichökonomischer Exzellenz (LOEWE) of the Land of Hessen. The Senckenberg Gesellschaft für Naturforschung and Goethe University in Frankfurt as well as other, directly involved partners, co‐operate closely with regional, national and international institutions in the fields of science, resource and environmental management, in order to develop projections for the future and scientific recommendations for sustainable action. For further details, please visit www.bik‐f.de

Sabine Wendler | Senckenberg

Further reports about: Beringia BiK-F Biodiversity Biodiversität Biology Climate Evolution Molecular Senckenberg history relationships

More articles from Life Sciences:

nachricht Building a better battery
29.06.2016 | Texas A&M University

nachricht New way out: Researchers show how stem cells exit bloodstream
29.06.2016 | North Carolina State University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Optical lenses, hardly larger than a human hair

3D printing enables the smalles complex micro-objectives

3D printing revolutionized the manufacturing of complex shapes in the last few years. Using additive depositing of materials, where individual dots or lines...

Im Focus: Flexible OLED applications arrive

R2D2, a joint project to analyze and development high-TRL processes and technologies for manufacture of flexible organic light-emitting diodes (OLEDs) funded by the German Federal Ministry of Education and Research (BMBF) has been successfully completed.

In contrast to point light sources like LEDs made of inorganic semiconductor crystals, organic light-emitting diodes (OLEDs) are light-emitting surfaces. Their...

Im Focus: Unexpected flexibility found in odorant molecules

High resolution rotational spectroscopy reveals an unprecedented number of conformations of an odorant molecule – a new world record!

In a recent publication in the journal Physical Chemistry Chemical Physics, researchers from the Max Planck Institute for the Structure and Dynamics of Matter...

Im Focus: 3-D printing produces cartilage from strands of bioink

Strands of cow cartilage substitute for ink in a 3D bioprinting process that may one day create cartilage patches for worn out joints, according to a team of engineers. "Our goal is to create tissue that can be used to replace large amounts of worn out tissue or design patches," said Ibrahim T. Ozbolat, associate professor of engineering science and mechanics. "Those who have osteoarthritis in their joints suffer a lot. We need a new alternative treatment for this."

Cartilage is a good tissue to target for scale-up bioprinting because it is made up of only one cell type and has no blood vessels within the tissue. It is...

Im Focus: First experimental quantum simulation of particle physics phenomena

Physicists in Innsbruck have realized the first quantum simulation of lattice gauge theories, building a bridge between high-energy theory and atomic physics. In the journal Nature, Rainer Blatt‘s and Peter Zoller’s research teams describe how they simulated the creation of elementary particle pairs out of the vacuum by using a quantum computer.

Elementary particles are the fundamental buildings blocks of matter, and their properties are described by the Standard Model of particle physics. The...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Conference ‘GEO BON’ Wants to Close Knowledge Gaps in Global Biodiversity

28.06.2016 | Event News

ERES 2016: The largest conference in the European real estate industry

09.06.2016 | Event News

Networking 4.0: International Laser Technology Congress AKL’16 Shows New Ways of Cooperations

24.05.2016 | Event News

 
Latest News

Building a better battery

29.06.2016 | Life Sciences

New way out: Researchers show how stem cells exit bloodstream

29.06.2016 | Life Sciences

Crucial peatlands carbon-sink vulnerable to rising sea levels

29.06.2016 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>