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highwaystar101 on 11 September 2010
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theprof00 said:

slimebeast is right, this isn't evolution.

This is an adaptation, possibly an adaptation that is simply a work-around that the skink has always been capable of. 

Now for the positive; this could become an evolution after a significant time period.

The basis of evolution is the change of gene structure based on environmental isolation. In the case of the skinks, they have:

a) environmental isolation, but not b) genetic difference (that we know of yet)

Over time environmental isolation leads to genetic differences because the majority of the species in isolation evolves according to genetics of the founding parents. Generally, the evolved ability is present in a small minority of the species, but once it becomes isolated, sometimes the trait becomes dominant if it improves reproductivity or survival.

Gradually, this trait becomes so genetically different the the species can no longer reproduce with the other side of the species.

Now, to counter slimebeast, taking off a sweater or putting one on is an ability that humans have to keep ourselves warm. However, most animals are capable of keeping themselves warm, it's just that we have figured out a way to make that ability mobile. Cats in the cold will hide under a house, but they can't take the house with them. So while the analogy is a good argument, you skim over the inherent evolution of wearing clothes in itself. Evolutions are almost never dramatic leaps of mutation, but co-adaptations that become a new ability, In the sense of clothing, those co-adaptations were "being able to hold things" and "being able to warm oneself". Those are two parts of an entirely new evolution. Humans aren't evolved to wear clothes. We are evolved to carry things and warm ourselves. 

Similarly in the skinks, they are evolved to  regulate their birthing method depending on temperature condition and they are evolved to carry eggs. These two traits may be combining to become "live birthing" skinks. I haven't read the actual article in the journal, so I don't know how pervasive these two traits already are in the skink population. What may end up happening is that only a small portion of skinks are capable of this egg regulation, but they will be become the dominant members of the isolated population. The only thing that's missing here is why they would live in the colder temperatures. There needs to be a motivation.

For example, if caves were full of food and warmth, humans would never need to wear clothing. Humans wore clothing because the north had clean water, lots of large wild animals, and less poisonous insects and vermin. It was natural to move there.

Now, if they can show me why the skinks are preferring to live in colder areas, I would have the proof I need to call this potential evolution, which it is.

That's what I've been saying all along isn't it? An extended period of this environmental pressure over many generations causing live birth will accumulate into an evolution. There will be a genetic difference if this occurs. I know it's not an evolution right now; It's an adaptation, but one that will lead to natural selection and perhaps eventually evolution if the need to continually adapt exists over a period of many generations.