Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ancient DNA identifies donkey ancestors, people who domesticated them

29.07.2010
Genetic investigators say the partnership between people and the ancestors of today's donkeys was sealed not by monarchs trying to establish kingdoms, but by mobile, pastoral people who had to recruit animals to help them survive the harsh Saharan landscape in northern Africa more than 5,000 years ago.

The findings, reported today by an international research team in Proceedings of the Royal Society B, paint a surprising picture of what small, isolated groups of people were able to accomplish when confronted with unpredictable storms and expanding desert.

"It says those early people were quite innovative, more so than many people today give them credit for," said senior author Connie J. Mulligan, Ph.D., an associate professor of anthropology at the University of Florida and associate director of the UF Genetics Institute. "The domestication of a wild animal was quite an intellectual breakthrough, and we have provided solid evidence that donkey domestication happened first in northern Africa and happened there more than once."

Sorting through the most comprehensive sampling of mitochondrial DNA ever assembled from ancient, historic and living specimens, scientists determined that the critically endangered African wild ass -- which today exists only in small numbers in eastern Africa, zoos and wildlife preserves -- is the living ancestor of the modern donkey.

What's more, researchers found evidence to suggest that a subspecies called the Nubian wild ass, presumed vanished late in the 20th century, is not only a direct ancestor of the donkey -- it may still exist.

The ancestors of the domestic donkey were considered vital for collecting water, moving desert households and creating the first land-based trade routes between the ancient Egyptians and the Sumerians, according to study co-author Fiona B. Marshall, Ph.D., a professor of anthropology at Washington University in St. Louis.

An Old World prehistorian, Marshall has documented evidence of the donkey's domestic service by looking at skeletal wear and tear of animal remains found entombed near Egyptian pharaohs.

In the new study, scientists traced the family trees of the domestic donkey using samples from living animals, skeletons of African wild ass held in museums worldwide and isolated donkey bones from African archaeological sites.

"These were the first transport animals, the steam engines of their day," Marshall said. "Today domestic donkeys are often conceived of as animals of poor people, and little is known about their breeding. This is the first study to determine the African wild ass, which includes the Nubian strain, is the ancestor of the domestic donkey. That's important to know for efforts to preserve the species."

There are small numbers of the Somali subspecies of the African wild ass in zoos and wildlife preserves, and about 600 still exist in the wild in Eritrea and Ethiopia, but the Nubian subspecies was last seen in the Red Sea Hills of Sudan late in the 20th century.

Hope for its continued existence springs from a sample collected in northern Africa in the mid-1990s by co-author and biologist Albano Beja-Pereira of the University of Porto, Portugal. If any Nubian survivors are found, the possibility remains that the animals could be bred and reintroduced into the wild. The evidence reinforces the need for surveys and wildlife management plans in eastern Sudan and northern Eritrea, researchers say.

"The whole idea behind conservation is the need to maintain genetic variation," Mulligan said. "We don't know which elements are more or less important, but we think the whole range of diversity is important to the health of the species. Knowing the genetic makeup of the animals is essential to protect that diversity."

In addition, placing the domestication of the donkey in northern Africa helps scientists better understand the archaeological record and early culture of the area, researchers say.

"Knowing where a domestication event first occurred is important, because there are always cultural ramifications from being first," said Sandra Olsen, Ph.D., curator of anthropology at the Carnegie Museum of Natural History in Pittsburgh, who did not participate in the research. "With a nucleus of animals that can serve as either a food source, transportation or some other purpose, particular cultures acquire advantages that make them more successful than their neighbors. Consider that animals like the horse and the donkey were used for military purposes.

"From the point of view of a biologist or someone who studies animal husbandry, it is interesting to find the source for a species because it can even have veterinary ramifications," she said. "The work done in this project is extraordinary. They located very hard to find samples not common at all in museums, and the archeological specimens are difficult to obtain positive results from because the heat often destroys the organic material. They've made some considerable advances."

Besides revealing that the African wild ass is the living ancestor of today's domestic donkeys, the genetic evidence also reveals that the Somali wild ass is not a living ancestor as once suspected, but closer akin to a more modern cousin.

That leaves a question of a remaining, yet unidentified ancestor of modern donkeys believed to have sprung from a different branch of the family. Researchers suspect that ancestors of this animal are extinct, but they may have roamed the Maghreb of northeastern Africa, and possibly the coast of Yemen.

The research was initiated by funding from the National Science Foundation and also supported by the Wildlife Trust, St. Louis Zoo, Basel Zoo, Liberec Zoo and the Sea World and Busch Gardens Conservation Fund.

Conservation samples were collected by co-authors Patricia D. Moehlman of the International Union for Conservation of Nature, Hagos Yohannes of the Eritrea Ministry of Agriculture and Fanuel Kebede of the Ethiopian Wildlife Conservation Authority.

Additional authors include Birgitta Kimura of Santa Fe College, Shanyuan Chen and Sonia Rosenbom of the University of Porto, Noreen Tuross of Harvard University, Richard C. Sabin of the Natural History Museum of South Kensington, London; Joris Peters of Ludwig-Maximilian University, Munich; Barbara Barich of Sapienza University of Rome, Redae Teclai of the Eritrea Ministry of Agriculture and Fanuel Kebede of the Ethiopian Wildlife Conservation Authority.

John Pastor | EurekAlert!
Further information:
http://www.ufl.edu

More articles from Life Sciences:

nachricht Meadows beat out shrubs when it comes to storing carbon
23.11.2017 | Norwegian University of Science and Technology

nachricht Migrating Cells: Folds in the cell membrane supply material for necessary blebs
23.11.2017 | Westfälische Wilhelms-Universität Münster

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>