| Slimebeast said: You're interpreting it wrong. There is not a dramatical difference between birthing traits. Actually there are no difference at all between traits. The only difference is that the guys in the northern cold retain the eggs longer, because it's cold, not because they're different than the southern guys. They explain the reason why it's possible (in this snake and in others), namely that the uterus secretes calcium to the thin eggs. But the guys in the south can do this too, it's just that there is no cold weather there to trigger the prolonged egg retainment. |
You do realize that mammals technically do the same thing right. Ever watch a dog have puppies? They come out in clear sacs, i.e. final remnants of what once were eggs.
The article is showing that these skinks are evolving to that same point. They started to keep eggs inside, over time eggs don't thicken up, to combat nutrient loss, the mom begins secreating calcium on her own... over time this will continue to not have yolk at all as the placenta fully develops. Its just the path to take for live birth similar to mammals. All the article is demonstrating is the beginning of that path. A path you seem to think is simply choice, not a slower change in the species. Unfortunately, neither of us will be around long enough to see the proof in concept.
However, the idea of evolution is stupid to argue against. We have evolved hundreds of animals and plants through forced selection (as opposed to natural selection). Why is it so hard to see its already happened. Just research the history of corn if you need further proof. Used to be tiny and only found in the America's. Now its massive (delicious) and grown in many places around the world. Compare cows in the US to those that have almost not selective breeding in India. Compare wild dog races to those of domesticated, big differences. Since they can still breed with eachother, its obvious they are nto different species, just races, yet they have very different capabilities due solely to human manipulation that is proof in concept for evolution.
