At what point is something a different species?

Given the existence of evolution, at what precise point is one defined as a new species? More specifically, at what point would a descendant of a homo sapien no longer be conisdered a homo sapien? Did I just blow your mind or what? :P (Okay, maybe not.)

(Probably futile request: Don't turn this thread into an argument about whether evolution exists or not please. We have plenty of those. Go start another thread if you're just here to say that you don't believe in evolution.)

It is complicated and I never try to get my head around it. A lot of time it's classed around the form of the skeleton and / or the eating habits. But mostly it's down to developing a habit which is unuseral for their species. Take a Camel Spider for instance, despite their name they don't get classed as aspider because they don't like the sun.

Technically speaking something is outside a species when they cease the ability to have fertile offspring. So when Homo Superior or whatever you want to call it is different enough that is loses the ability to have viable offspring with a Homo Sapian then we know it's become different. I doubt that will ever happen given our society though.Ace6301

Technically speaking something is outside a species when they cease the ability to have fertile offspring. So when Homo Superior or whatever you want to call it is different enough that is loses the ability to have viable offspring with a Homo Sapian then we know it's become different. I doubt that will ever happen given our society though.Ace6301

While that tends to be the most convenient definition, it's actually not an entirely accurate one. The question of what precisely defines a species is so problematic that it even has its own name. Probably the most well-known counterexample to that definition is that of the liger - the offspring of a male lion and a female tiger. A liger has even successfully been observed to bear offspring that survived to adulthood, to boot, so even the notion that species are defined by the ability to create fertile offspring is out. If anyone can successfully create a definition of species that perfectly encapsulates all known examples of species in existence, that person will be well-renowned by biologists indeed. :P

It is complicated and I never try to get my head around it. A lot of time it's classed around the form of the skeleton and / or the eating habits. But mostly it's down to developing a habit which is unuseral for their species. Take a Camel Spider for instance, despite their name they don't get classed as aspider because they don't like the sun.

Evil_Saluki

[QUOTE="Ace6301"]Technically speaking something is outside a species when they cease the ability to have fertile offspring. So when Homo Superior or whatever you want to call it is different enough that is loses the ability to have viable offspring with a Homo Sapian then we know it's become different. I doubt that will ever happen given our society though.GabuEx

While that tends to be the most convenient definition, it's actually not an entirely accurate one. The question of what precisely defines a species is so problematic that it even has its own name. Probably the most well-known counterexample to that definition is that of the liger - the offspring of a male lion and a female tiger. A liger has even successfully been observed to bear offspring that survived to adulthood, to boot, so even the notion that species are defined by the ability to create fertile offspring is out. If anyone can successfully create a definition of species that perfectly encapsulates all known examples of species in existence, that person will be well-renowned by biologists indeed. :P

Also a very good point.SpaceMoose

The bottom line is that the answer to your question is... no one really has any clue. :P We can identify tons upon tons of examples of what we consider to be distinct species, but to my knowledge no one has yet devised an actual definition of "species" that works in all cases.

What we define as a different species or a different subspecies or a different race is purely subjective. We set the lines were we want them. This is why many people say that human "races" or human "subspecies" are social constructs and don't really exist as physical entities.

[QUOTE="SpaceMoose"]Also a very good point.GabuEx

The bottom line is that the answer to your question is... no one really has any clue. :P We can identify tons upon tons of examples of what we consider to be distinct species, but to my knowledge no one has yet devised an actual definition of "species" that works in all cases.

[QUOTE="Evil_Saluki"]

It is complicated and I never try to get my head around it. A lot of time it's classed around the form of the skeleton and / or the eating habits. But mostly it's down to developing a habit which is unuseral for their species. Take a Camel Spider for instance, despite their name they don't get classed as aspider because they don't like the sun.

SpaceMoose

Camel Spiders are some wicked a** creatures. Just thought I would say that.

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