4 ms·

I thought a big part of that was that birds have big variation between juveniles and adults, something that mammalians have less of... (let alone primates) Loo

I thought a big part of that was that birds have big variation between juveniles and adults, something that mammalians have less of... (let alone primates) Looking at a time when multiple hominid groups lived in relative isolation over large spans of time, admittedly without expert knowledge, it seems to make sense to me that there would be quite a bit of variation of "species" (though I also suspect the various species are more alike than most breeds of dogs...)

thaumasiotes 5y ago
> I thought a big part of that was that birds have big variation between juveniles and adults, something that mammalians have less of... You should see what insects do. It just isn't possible, using fossil records alone, to identify whether two insects belong to the same or different species.
- shahar2k 5y ago
  yeah and that's what is behind the idea that some "different" dinosaur species (aka birds) are actually juvanile / adult versions of the same species totally amazing that insects basically rearrange themselves on near celular level though at certain points in their lifespan
  - thaumasiotes 5y ago
    > totally amazing that insects basically rearrange themselves on near celular level though at certain points in their lifespan What I find more amazing is that, in the popular culture, this is usually presented as something unusual that butterflies do. When in reality all insects do it and the metamorphosis of butterflies is notable only for its extreme typicality.
gunapologist99 5y ago
Interesting point. In the process of adopting a pure-bred Slovakian-line GSD, I've learned that German Shepherd Dogs didn't exist at all until the early 1900's, and the modern Slovakian line (which is related to the DDR line, which is when the two lines became rapidly and visibly diversified when the Iron Curtain divided Germany from the late 40's to the late 80's) is in danger of fading away altogether. And that was only in 40 years -- admittedly with intentional breeding, but it's conceivable that changes in diet, parasites, tumultuous periods of history, seismic changes, or even war/pillaging/violence could rapidly change the makeup of an entire continent within just a few decades. In fact, we've seen that in very recent history.

thaumasiotes 5y ago

> I thought a big part of that was that birds have big variation between juveniles and adults, something that mammalians have less of... You should see what insects do. It just isn't possible, using fossil records alone, to identify whether two insects belong to the same or different species.

shahar2k 5y ago
yeah and that's what is behind the idea that some "different" dinosaur species (aka birds) are actually juvanile / adult versions of the same species totally amazing that insects basically rearrange themselves on near celular level though at certain points in their lifespan
- thaumasiotes 5y ago
  > totally amazing that insects basically rearrange themselves on near celular level though at certain points in their lifespan What I find more amazing is that, in the popular culture, this is usually presented as something unusual that butterflies do. When in reality all insects do it and the metamorphosis of butterflies is notable only for its extreme typicality.

gunapologist99 5y ago

Interesting point. In the process of adopting a pure-bred Slovakian-line GSD, I've learned that German Shepherd Dogs didn't exist at all until the early 1900's, and the modern Slovakian line (which is related to the DDR line, which is when the two lines became rapidly and visibly diversified when the Iron Curtain divided Germany from the late 40's to the late 80's) is in danger of fading away altogether. And that was only in 40 years -- admittedly with intentional breeding, but it's conceivable that changes in diet, parasites, tumultuous periods of history, seismic changes, or even war/pillaging/violence could rapidly change the makeup of an entire continent within just a few decades. In fact, we've seen that in very recent history.