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lionhart280 t1_is2xbwa wrote

I thought I heard awhile back this is because they arent hybrid animals, turns out.

I thought it was found that grizzly bears and polar bears are the same bears, just different colors, or at least are so genetically close you may as well just call them different breeds of the same species, thus it makes sense their offspring can still breed.

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Sea-Amoeba-3388 t1_is3p9ms wrote

This is it. The ability to have viable offspring is the definition of a species.

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KindOfABugDeal t1_is50oxk wrote

It's the 'taught to high schoolers' definition of a species, the biological species concept is outmoded and no longer really used in the real world. Instead, people now mostly focus on genetics.

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Sea-Amoeba-3388 t1_is56h3d wrote

What would be a good, up-to-date layman's definition of a species.

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KindOfABugDeal t1_is5kupq wrote

The focus these days is on genetic isolation. Generally, a species would be defined as a genetically compatible interbreeding population, or group of populations, that is genetically isolated from other groups.

Reproductive compatibility is a component of that, in that successful reproduction is important for an interbreeding population to exist, but it's not the sole or primary requirement. I'm an entomologist, and I've always been a fan of the morphological species concept, but genetics has shown that multiple genetically distinct species can exist under the same morphological umbrella. Also, some species that are morphologically distinct may not be genetically isolated enough to actually be described as distinct species. The morphological species concept is still used, but not many people want to spend their lives dissecting beetle genitalia under a microscope when they can just grind up a tarsal segment for DNA barcoding instead.

Phylogenetic relationships are complex enough that they can be confusing for high school and college students, as well as adults without a strong biology background. Couple that with the fairly terrible science curricula in the US, and you end up with broad acceptance of the biological species concept.

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