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Surely if they can reliably interbreed with us then they're not another species. Isn't that how "species" is defined? You'll note that the scientists in the art

by hugh3 16y ago

Surely if they can reliably interbreed with us then they're not another species. Isn't that how "species" is defined? You'll note that the scientists in the article aren't quoted as calling these dudes a "species", they call them a "form". The idea of a "species" isn't terribly well defined over time anyway. Your mother is the same species as you, her mother is the same species as her, and so on. But if you keep following your family tree for far enough you'll start to find things which are clearly a different species from yourself.

scott_s 16y ago
The definition I'm aware of is not actually can they interbreed, but do they do it in practice? From http://www.sciencedaily.com/releases/2005/02/050211082447.htm http://www.sciencedaily.com/releases/2005/02/050211082447.ht...: Members of closely related species possess no physiological differences that would prevent them from interbreeding. But closely related species are distinguished by subtle differences in the pulse rates of male crickets' simple courtship songs, a secondary sexual trait that plays a large role in mate attraction. Among all species of Laupala, pulse rates of male courtship songs range from .5 to 4.2 pulses per second. Female crickets can detect these differences, says Mendelson, and they tend to hop towards the pulse rate of their own species and to reject songs sung at a different tempo. Despite the fact that these crickets can interbreed (and produce fertile offspring, unlike when, say, a female horse and a male donkey produce an infertile mule), we consider them different species because they systematically do not breed. I recall reading about further experiments with similar crickets where scientists manipulated the pulse rates of one cricket species to be the same as the other. Mating occurred.
- dkarl 16y ago
  I think behavioral and genetic barriers are both considered factors that affect whether crickets "can" interbreed. I'm not sure if scientists would be consistent in applying that standard to humans, though.
necolas 16y ago
There are many different ways to define what constitutes a separate species. The inability to produce viable offspring is just one.
- dkarl 16y ago
  The difficulties of defining species lead to interesting edge cases, some of which show up in nature, such as ring species: http://en.wikipedia.org/wiki/Ring_species http://en.wikipedia.org/wiki/Ring_species Formally, the issue is that interfertile "able to interbreed" is not a transitive relation – if A can breed with B, and B can breed with C, it does not follow that A can breed with C – and thus does not define an equivalence relation. A ring species is a species that exhibits a counterexample to transitivity.
brc 16y ago
Well a great dane and a chihouha are both the same species - dog. But I wouldn't see them getting it on anytime soon. And yes, you can artificially breed a dane/chihouha hybrid (presuming the resulting pup has a Dane mother?)

by hugh3 16y ago

scott_s 16y ago

The definition I'm aware of is not actually can they interbreed, but do they do it in practice? From http://www.sciencedaily.com/releases/2005/02/050211082447.htm http://www.sciencedaily.com/releases/2005/02/050211082447.ht...: Members of closely related species possess no physiological differences that would prevent them from interbreeding. But closely related species are distinguished by subtle differences in the pulse rates of male crickets' simple courtship songs, a secondary sexual trait that plays a large role in mate attraction. Among all species of Laupala, pulse rates of male courtship songs range from .5 to 4.2 pulses per second. Female crickets can detect these differences, says Mendelson, and they tend to hop towards the pulse rate of their own species and to reject songs sung at a different tempo. Despite the fact that these crickets can interbreed (and produce fertile offspring, unlike when, say, a female horse and a male donkey produce an infertile mule), we consider them different species because they systematically do not breed. I recall reading about further experiments with similar crickets where scientists manipulated the pulse rates of one cricket species to be the same as the other. Mating occurred.

dkarl 16y ago
I think behavioral and genetic barriers are both considered factors that affect whether crickets "can" interbreed. I'm not sure if scientists would be consistent in applying that standard to humans, though.

necolas 16y ago

There are many different ways to define what constitutes a separate species. The inability to produce viable offspring is just one.

dkarl 16y ago
The difficulties of defining species lead to interesting edge cases, some of which show up in nature, such as ring species: http://en.wikipedia.org/wiki/Ring_species http://en.wikipedia.org/wiki/Ring_species Formally, the issue is that interfertile "able to interbreed" is not a transitive relation – if A can breed with B, and B can breed with C, it does not follow that A can breed with C – and thus does not define an equivalence relation. A ring species is a species that exhibits a counterexample to transitivity.

brc 16y ago

Well a great dane and a chihouha are both the same species - dog. But I wouldn't see them getting it on anytime soon. And yes, you can artificially breed a dane/chihouha hybrid (presuming the resulting pup has a Dane mother?)