Science News, Oct 14, 2006 by B. Bower
Present-day domestic goats may look humble, but they harbor more genetic diversity than any other livestock species. In fact, analyses of goats’ mitochondrial DNA have shown that these animals evolved through five distinct maternal lines that spread from the Near East and central Asia across Europe.
A new study indicates that goats representing the earliest two of the five genetic lines inhabited the same location in southwestern Europe by about 7,000 years ago, only 3,000 years after the initial domestication of the animals in the Near East.
This ancient genetic diversity in a region far from the goat strains’ origins reflects the long-distance transport of goats from the Near East by European pioneers soon after the origins of animal domestication, farming, and village life, say geneticist Pierre Taberlet of Joseph Fourier University in Grenoble, France, and his colleagues in an upcoming Proceedings of the National Academy of Sciences.
Today’s other three genetic lines arose later in parts of central Asia, Taberlet’s group proposes.
The scientists analyzed mitochondrial DNA retrieved from 19 goat bones found at an ancient farming site in southern France. Other researchers had excavated these fossils about 20 years ago in soil that contained the remains of more than 5,000 animals, including pigs, cattle, and sheep.
New radiocarbon measurements of five goat bones placed them at between 7,300 and 6,900 years old.
By extracting and analyzing genetic material from several goat bones, two independent laboratories confirmed that the sequences that Taberlet’s group examined were uncontaminated, ancient DNA.
Comparisons of the ancient goat mitochondrial DNA with sequences of modern goat DNA revealed that the two Near Eastern lineages had inhabited the prehistoric French site at the same time.
Taberlet and his colleagues suspect that early farmers transported each line of goats into Europe along a separate westward route, one inland and the other running along the Mediterranean Sea.
A preference for moving goats long distances in ancient times makes sense (SN: 5/12/01, p. 294). Goats are the hardiest livestock species. They’re easy to transport by land or boat, and they willingly follow people.
The new data convincingly show the domestication of two ancient goat lineages at the same time somewhere in the Fertile Crescent region, remarks archaeobiologist Melinda A. Zeder of the Smithsonian Institution’s National Museum of Natural History in Washington, D.C.
Genetic studies of modern domestic sheep have revealed a pattern similar to that of goats, with three to four ancient lineages, Zeder notes. “This suggests that both sheep and goats moved together, as they do today, in mixed herds as they diffused out of the Near East,” she says.
Also..
Archaeological data suggest two distinct places of domestication: the Euphrates river valley at Nevali Çori, Turkey (11,000 bp), and the Zagros Mountains of Iran at Ganj Dareh (10,000). Other possible sites of domestication include the Indus Basin in Pakistan at (Mehrgarh, 9,000 bp) and perhaps central Anatolia and the southern Levant.
And, a DNA study on goats.
Helena Fernández*, Sandrine Hughes,,, Jean-Denis Vigne¶, Daniel Helmer||, Greg Hodgins**, Christian Miquel*, Catherine Hänni,, Gordon Luikart*,, and Pierre Taberlet*,
Goats were among the first farm animals domesticated, 10,500 years ago, contributing to the rise of the “Neolithic revolution.” Previous genetic studies have revealed that contemporary domestic goats (Capra hircus) show far weaker intercontinental population structuring than other livestock species, suggesting that goats have been transported more extensively. However, the timing of these extensive movements in goats remains unknown. To address this question, we analyzed mtDNA sequences from 19 ancient goat bones (7,300–6,900 years old) from one of the earliest Neolithic sites in southwestern Europe. Phylogenetic analysis revealed that two highly divergent goat lineages coexisted in each of the two Early Neolithic layers of this site. This finding indicates that high mtDNA diversity was already present >7,000 years ago in European goats, far from their areas of initial domestication in the Near East. These results argue for substantial gene flow among goat populations dating back to the early neolithisation of Europe and for a dual domestication scenario in the Near East, with two independent but essentially contemporary origins (of both A and C domestic lineages) and several more remote and/or later origins.
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