New Giant Tortoise Species Found on Galápagos Islands
news.nationalgeographic.com
New Giant Tortoise Species Found on Galápagos Islands
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Re: New Giant Tortoise Species Found on Galápagos Islands
#2Re: New Giant Tortoise Species Found on Galápagos Islands
#3Re: New Giant Tortoise Species Found on Galápagos Islands
#4I hope they don't do to it what they did to the giant squid when they discovered that too (kill it).
Re: New Giant Tortoise Species Found on Galápagos Islands
#5The fact that members of all of these groups readily hybridize would violate some interpretations of the concept of species. The article exposes the arbitrariness of the concept. Also, mtDNA and microsatellites (short stretches of repetitive DNA that expand and contract quickly) offer only a fragmentary picture of genetic history. It is unfortunate that the researchers were not able to use modern sequencing technique…
That said, where and when hybridization is possible is a complex question. For example consider the following pairs of species. (polar bears, brown bears), (horses, donkeys), (humans, chimpanzees). All are at about the same evolutionary distance from each other (current estimates are 5 million years, 4.5 million years and 6 million years). The bears happily interbreed, the equines interbreed but the babies are not generally fertile, and there are no reports of successful human/chimpanzee crosses. (No reports of anyone admitting to trying either, but it would be hard to believe that the attempt was nowhere made.)
Yet in all three cases, biologists generally agree that those are pairs of distinct species.
Re: New Giant Tortoise Species Found on Galápagos Islands
#6Re: New Giant Tortoise Species Found on Galápagos Islands
#7Re: New Giant Tortoise Species Found on Galápagos Islands
#8The fact that members of all of these groups readily hybridize would violate some interpretations of the concept of species. The article exposes the arbitrariness of the concept. Also, mtDNA and microsatellites (short stretches of repetitive DNA that expand and contract quickly) offer only a fragmentary picture of genetic history. It is unfortunate that the researchers were not able to use modern sequencing technique…
The existence of ring species says that there must be arbitrariness in deciding where to draw the line. See https://en.wikipedia.org/wiki/Ring_species for an explanation. That said, where and when hybridization is possible is a complex question. For example consider the following pairs of species. (polar bears, brown bears), (horses, donkeys), (humans, chimpanzees). All are at about the same evolutionary distance fro…
Re: New Giant Tortoise Species Found on Galápagos Islands
#9I hope they don't do to it what they did to the giant squid when they discovered that too (kill it).