Argument #1: Transitional Fossils

[Esquilax]

I highly doubt the level of intelligence of a species will decide or not if they become extinct.

So you're saying that the fact that we are smart enough to invent things and form highly technological societies played no part in our success as a species?

I also don't understand how extinction supports evolution?

It's more that it doesn't support intelligent design: the majority of creatures on this planet have failed and died off, something that the intelligent designer you're positing would know ahead of time, and yet still decided to waste his effort creating these species, that don't evolve, and so there was no need for him to do that.

The facts just don't support the idea that there's a conscious entity cooking up organisms.