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Thought experiment. Three populations, A, B, and C, divided geographically along a line. Individuals from group A can breed successfully with those from B but n
by bluebarbet 6mo ago
Thought experiment. Three populations, A, B, and C, divided geographically along a line. Individuals from group A can breed successfully with those from B but not with those from C. Individuals from group C can breed successfully with those from B but not A.
How many species are there? This is why the term "species" can never be entirely objective. I remember the eureka moment I had when I finally understood this (admittedly somewhat simple) point.
- naasking 6mo agoIt can even be more subtle, it's entirely possible that some rare members of A can C breed, and some members of C and B would not be able to breed. The "fertility" relation can only be decided between two individuals, not groups. Group-level fertility is a statistical average of individual fertility. That said, I don't think that means that "species" is entirely subjective or meaningless.
- lukan 6mo agoIs that based on a real example or hypothetical?
- usrnm 6mo agohttps://en.wikipedia.org/wiki/Ring_species https://en.wikipedia.org/wiki/Ring_species
- afpx 6mo agoEven within one species, not every individual can successfully breed with every other.