2 ms·
Isn't the ability to produce fertile offspring a de facto proof that two organisms are of the same species?
by yawaramin 11y ago
Isn't the ability to produce fertile offspring a de facto proof that two organisms are of the same species?
- scarmig 11y agoDepends on the context, but generally nope. Consider the example of "ring species"--A can breed with B, B with C, .., Y with Z, and Z with A. However, A can't interbreed with M. What's the species? That's a somewhat rare version of a general pattern where that abstraction is leaky. Much more common is a temporal version of that. A might beget A1 and B, with A1 begetting A2 and B begetting C, continuing all the way down. And though A can interbreed with A1 and B, and B with C, etc, Z can't interbreed with A25. That's speciation, which happens all the time. The only thing that makes it a clear species is defining the concept species while abandoning time invariance.