(Press-News.org) The morphology of coelacanths has not fundamentally changed since the Devonian age, that is, for about 400 million years. Nevertheless, these animals known as living fossils are able to genetically adapt to their environment. This is described by PD Dr. Kathrin Lampert from the RUB's Department of Animal Ecology, Evolution and Biodiversity along with colleagues from Würzburg, Bremen, Kiel and Dar es Salaam (Tanzania) in the journal Current Biology. "Coelacanths are rare and extremely endangered. Understanding the genetic diversity of these animals could help make preservation schemes against their extinction more effective" says the biologist.
Different populations in Africa studied
Previous genetic studies focused mainly on the biological relationships of coelacanths to lungfish and and vertebrates. In order to assess whether the fish are still able to adapt to new environmental conditions, however, you have to know the genetic diversity within the species. For this purpose, the research team examined 71 specimens from various sites on the east coast of Africa. The researchers analysed genetic markers from the nucleus and from the mitochondria, the powerhouses of the cells.
Geographical differences in the genetic makeup
The data generally revealed low genetic diversity. As presumed, the evolution of these animals is only progressing slowly. Nevertheless, certain genetic patterns were only found in certain geographic regions. "We assume that the African coelacanth originally came from around the Comoros Islands, home to the largest known population" Lampert explains. Since then, however, two further, now independent populations have established themselves in South Africa and Tanzania. In addition, the animals around the Comoros belong to two genetically distinct groups. "We have thus been able to show that despite their slow evolutionary rate, coelacanths continue to develop and are potentially also able to adapt to new environmental conditions" says the RUB researcher. "The image of the coelacanth as a passive relic of bygone times should therefore be put into perspective".
Link between water and land
Coelacanths, Latimeria chalumnae, were regarded as extinct until Marjorie Courtenay-Latimer discovered a live specimen on a fishing boat in 1938. Since then, more than a hundred have been found off the coast of East Africa, most of them off the Comoros. There are probably only a few hundred specimens left in the world, which are seriously threatened with extinction. "Coelacanths are close relatives of the last common ancestor of fish and land vertebrates, and therefore of great scientific interest", says Kathrin Lampert. "By researching them, we hope to gain new insights into one of the major steps of evolution: the colonisation of land."
INFORMATION:
Bibliographic record
K.P. Lampert, H. Fricke, K. Hissmann, J. Schauer, K. Blassmann, B.P. Ngatunga, M. Schartl (2012): Population divergence in East African coelacanths, Current Biology, doi: 10.1016/j.cub.2012.04.053
Further information
PD Dr. Kathrin Lampert, Department of Animal Ecology, Evolution and Biodiversity, Faculty of Biology and Biotechnology at the Ruhr-Universität, 44780 Bochum, Germany, Tel. +49/234/32-25573
kathrin.lampert@rub.de
Editor: Dr. Julia Weiler
END
The use of genetic testing to establish racial origins for political purposes is not only scientifically foolish, but also unethical and should be condemned, the European Society of Human Genetics (ESHG) said today (Thursday June 14). The society, which promotes research in basic and applied human and medical genetics and ensures high standards in clinical genetic practice, said that the use by a member of parliament from the Hungarian far-right Jobbik party of a genetic test to attempt to prove his 'ethnic purity' was ethically unacceptable.
The company Nagy Gén scanned ...
New research from psychologists at the Universities of Exeter and Cardiff shows that people can train their brains to become less impulsive, resulting in less risk-taking during gambling. The research could pave the way for new treatments for people with addictions to gambling, drugs or alcohol as well as impulse-control disorders, such as ADHD.
Published today (14 June 2012), in the journal Psychological Science, the study assessed whether asking people to stop making simple movements while in a simulated gambling situation affected how risky or cautious they were ...
Character strengths can be defined as traits that are rated as morally positive. That they are positively linked to life satisfaction has already been shown in many studies. That they have a causal effect on life satisfaction and that practicing them triggers an increase in the sense of wellbeing, however, has now been proved by Willibald Ruch, René T. Proyer and Claudia Buschor from the Department of Personality and Assessment at the University of Zurich for the first time.
Practice pays off
For their current study, the team of researchers randomly divided a sample ...
When people say "Blood is thicker than water," they are literally right. Because nearly half of the 'life liquid' consists of solid components. The red blood cells form the greatest part of it – all in all around 40 percent of the blood. They contain the red pigment hemoglobin and are responsible for the transport of oxygen.
"It is amazing that the percentage of this component is not only similar in all human beings but also in many other vertebrates," Prof. Dr. Stefan Schuster of the Friedrich Schiller University Jena (Germany) says. Therefore it can be assumed that ...
While youth suicide is declining overall, the rate of youth suicide in rural America has remained steady. A key to helping rural families with children at risk of suicide is frank discussion of guns says Jonathan Singer, assistant professor of social work at Temple University and co-author of a new study that examined how clinicians, including social workers and counselors involve parents in prevention and treatment of youth suicide. The study, "Engaging parents of suicidal youth in a rural environment" was published in the May issue of Child & Family Social Work.
Singer ...
To address the question about how climate may develop in the future, earth scientists direct their attention to the past. They look for epochs with similar conditions to today. The major identified climatic processes are then simulated with numerical models to further test possible reactions of the Earths' system. An epoch which is often regarded suitable for such an undertaking is the Eemian warm period, which began around 125,000 years ago following the Saalian ice age.
For about 10,000 years, average temperatures on Earth in the Eemian were rather enhanced – probably ...
New research from scientists at McMaster University reveals exercise-related testosterone and growth hormone do not play an influential role in building muscle after weightlifting, despite conventional wisdom suggesting otherwise.
The findings indicate that bodybuilders who look to manipulate those hormones through exercise routines are wasting their time.
In two separate studies, published in the Journal of Applied Physiology and the European Journal of Applied Physiology, researchers found anabolic hormones—long thought to be essential for building a muscular frame—do ...
Using individual molecules instead of electronic or magnetic memory cells would revolutionise data storage technology, as molecular memories could be thousand-fold smaller. Scientists of Kiel University took a big step towards developing such molecular data storage. They succeeded in selectively switching on and off the magnetism of individual molecules, so-called spin-crossover complexes, by electrons. The interdisciplinary study is part of the Collaborative Research Centre 677 "Functions by Switching", which is funded by the German Research Foundation (DFG). The results ...
People who were sexually unfaithful without their partner's knowledge were less likely to practice safe sex than those who had other sexual relationships with their partner's consent. They were also more likely to be under the influence of drugs and alcohol at the time of the encounter.
In a study published in The Journal of Sexual Medicine, researchers from the University of Michigan, USA, found that condom use for vaginal and anal sex was 27% and 35% lower in sexually unfaithful relationships and drug and alcohol use was 64% higher.
Of the 1,647 people who replied ...
Adult lesbian and bisexual women are more likely to report childhood abuse and adult sexual assault than heterosexual women, according to a new study by Dr. Keren Lehavot from the VA Puget Sound Health Care System in Seattle, USA and her collaborators. Furthermore, the researchers' work shows that women who are more butch report more abuse in childhood, particularly physical and emotional neglect, while women who identify as femme, and have a more feminine appearance, report more adult sexual assaults. The work is published online in Springer's journal, Sex Roles.
It ...
