We are in violent agreement. Their in the Bear family, not genus. Yet, most refer to them as bears, and from what I've read they were formerly thought to be closer to the racoon?!
Contrary to popular belief on these threads there’s no on/off switch for speciation, it’s a process involving diminishing fertility and/or breeding opportunities.
When a barrier is erected that prohibits further breeding, whatever that barrier is, speciation is often the result. By that rule, then, the Great Dane and the Chihuahua may be thought of as seperate species, for I doubt you could get them to breed.
[[By that rule, then, the Great Dane and the Chihuahua may be thought of as seperate species, for I doubt you could get them to breed. ]]
Oh I dunno- with hte proper candlelight, flowers, low light- anythign is possible
You sound thoughtful, so let’s play genetics...
Remember I said speciation is not an on/off switch so:
east to west (oversimplified):across a flat continent eastern squirrels can breed with midwestern squirrels and midwestern squirrels can breed with western squirrels. But eastern squirrel can’t breed with western ones. How many species? Now kill all the midwestern ones from a major fire. How many species?
ring: same idea but forming a ring, the ends of which can’t breed (google “ring species” and check several different ones)
for dogs: line up the breeds by size: each can breed with the adjacent but not with the one 3 sizes down...the kicker here is the artificial breeding. Left to themselves they’d even out over time
Plants cause confusion by developing species complexes, often using polyploidy (instead of having chromosomes in pairs, some members of the complex will have them in threes or fours, and some can breed and some can’t.
You might also google “recent speciation” for more fun.
Oh, and Lesser Pandas are more closely related to raccoons than to bears. Different family. That, and things like the rose/pear example show why I’m a stickler for not using common names as a basis for showing relationship. Also, right now there are some arguments for putting the larger pandas into their own family. Don’t know who’s winning. If you go to the “Tree of Life Web Project” you’ll see them listed twice.