| Slimebeast said: Stop. Your interpretation is wrong. That whole segment discusses the differences between egg and placenta in general, not about this particular skink's northern and southern populations. |
For the love of God man, are you really incapable of expanding on the ideas presented in the article?
The article says there is ONE species of skinks with TWO dramatically different birthing traits.
Southern population lays eggs like other reptiles. It later says that animals that lay eggs (which would by default include these southern skinks) provide calcium to the embryo via the thick shell.
The article then clearly says that the northern population give LIVE BIRTH, with a picture even. It later says that animals that give birth use a placenta to provide nutrients like calcium and that without a thick egg they would presume these skinks would potentially have defects. They then realized in these skinks that the mother has traits of an early placenta and give the embryo calcium directly to make up for the lack of a thick shell.
How are you missing this relationship in the article? The author assumes that its readers can grasp the bigger connections here between the egg laying and live birth skinks to the general idea of the difference between eggs and placenta.
