by Tdarcos » Sat Mar 11, 2023 8:01 pm
Now that I discussed the idea of evolution, genetic changes over time. Now here's another point to be made and that is that as those changes diverge more and more from the original organisn, the species of the new one will change.
We don't know exactly when - at which point - because species is not a hard, drop dead line. As long as two entities can breed with each other, they are of the same species This means we get "transitional" species, one that can breed with each other and with close generation later ones, but the later ones can't breed with the prior ones
To make this simpler, let's take species"A" which breeds, and it's descendants breed, and eventually the new breeds develop into something different, B. A and B can breed with each other. Eventually B evolves into species C. C is somewhat different from B, but they can still breed with them. They might or might not be able to breed with A. Eventually C evolves to become D. But, as with the others,, D can breed with C and D. But it can'tt breed with A or B. While A and D are clearly separate species, are B or C?
This has been seen out in the wild. There is a place where a South river split into two tributaries, East and West. A species of fish grew native to the south river continued up to the tributaries, some going eouth, others going west, then becoming trapped and unable to go back downstream. Fish on each side of the river adapt to changes in the river ecosystem, These species each developed differently from each other. South river fish swam into either branch, could breed with either, but the East fish can only breed with South and East, and West fish can only breed with South and West.
At some point the river merged into the North river. Ñow you have one species and two transitional ones: South, East, and West. As conditions change, some or all of these may go extinct, but for those that survive, if conditions are differen enough, yet another species. Or perhaps more.
Now that I discussed the idea of evolution, genetic changes over time. Now here's another point to be made and that is that as those changes diverge more and more from the original organisn, the species of the new one will change.
We don't know exactly when - at which point - because species is not a hard, drop dead line. As long as two entities can breed with each other, they are of the same species This means we get "transitional" species, one that can breed with each other and with close generation later ones, but the later ones can't breed with the prior ones
To make this simpler, let's take species"A" which breeds, and it's descendants breed, and eventually the new breeds develop into something different, B. A and B can breed with each other. Eventually B evolves into species C. C is somewhat different from B, but they can still breed with them. They might or might not be able to breed with A. Eventually C evolves to become D. But, as with the others,, D can breed with C and D. But it can'tt breed with A or B. While A and D are clearly separate species, are B or C?
This has been seen out in the wild. There is a place where a South river split into two tributaries, East and West. A species of fish grew native to the south river continued up to the tributaries, some going eouth, others going west, then becoming trapped and unable to go back downstream. Fish on each side of the river adapt to changes in the river ecosystem, These species each developed differently from each other. South river fish swam into either branch, could breed with either, but the East fish can only breed with South and East, and West fish can only breed with South and West.
At some point the river merged into the North river. Ñow you have one species and two transitional ones: South, East, and West. As conditions change, some or all of these may go extinct, but for those that survive, if conditions are differen enough, yet another species. Or perhaps more.