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FreeRepublic , LLC PO BOX 9771 FRESNO, CA 93794
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Posted on 01/21/2003 12:23:43 PM PST by CobaltBlue
EVERY mammal, including Man, is descended from a creature that was genetically similar to the modern aardvark, scientists have found.
The last common ancestor of the placental mammals lived about 100 million years ago and had a genetic profile that is closer to that of the African anteater than to any other species that survives today, according to new research.
Detailed analysis of the chromosomes of several representative species — including aardvarks, African and Asian elephants and human beings — has revealed that the aardvark has the greatest number of features in common with other mammals. That suggests that it is the closest living relative of our common ancestor — a kind of mammalian missing link.
The findings, by British, Chinese and South African scientists, do not necessarily mean that the last common mammalian ancestor looked like a modern aardvark, or that it survived by eating insects.
They show, however, crucial chromosomal similarities that will cast important new light on the process by which mammals evolved and came to dominate the Earth. Details of the study are published today in the journal Proceedings of the National Academy of Sciences.
Fengtang Yang, of Cambridge University, who led the research, said: “The chromosomal make-up of the common ancestor closely resembles that of the modern aardvark. The ancestor, though, was not necessarily morphologically similar: chromosomal evolution and morphological evolution are not always parallel.”
The aardvark, which means “earth pig” in Afrikaans, is a nocturnal animal that lives all over Africa, ranging from southern Egypt to the Cape of Good Hope. It grows to about 5ft or 6ft in length, which includes a 2ft tail, and resembles a hump-backed, long-snouted overgrown rat.
It is an insectivore that thrives on ants and termites, which it collects using its long tongue and sticky saliva. The Latin name for the species is Orycteropus afer, meaning “one that has feet for digging, from Africa”, and it is the only member of the order Tubulidentata — one of the 18 orders of mammal.
The genetic study, which also involved researchers from Stellenbosch University in South Africa and the Chinese Academy of Sciences, examined the chromosomes of the aardvark, the African and Asian elephants, and people. Existing data about the chromosomal structure of other species, such as cattle, dogs and cats, were included.
The scientists said that the common ancestor probably belonged to a mammalian “super order” known as Afrotheria, which includes the aardvark and both species of elephant.
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FreeRepublic , LLC PO BOX 9771 FRESNO, CA 93794
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[This ping list for the evolution -- not creationism -- side of evolution threads, and sometimes for other science topics. To be added (or dropped), let me know via freepmail.]
See what happens when you do too much geneological research? Eventually, you won't be happy with what you discover.
This Aardvark?
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