The point of the first is that being a skeptic about certain aspects of Darwin's theory of evolution primarily through natural selection does not equate to being anti-science or scientifically inept.
Nope. It's point is to fool people into believing that the "controversy" about the validity of evolutionary biology is, in any way, scientific.
In fact, the truth of the purpose of the list, and the manner in which it was procured, leaves any reasonable observer to conclude that the Discovery Institute, who is responsible for it, had no goal in mind except to defraud the public and to bear false witness against science and those who practice science.
Those bastards.
The point of the second is to ridicule the first.
No, because you can't ridicule something that is, itself, already ridiculous.
The point of the second was to rebut the first and the notion that there was actually anything scientific about the "controversy" surrounding evolution.
And to press home that point, the sponsors of the second petition limited signatories to those who name was "Stephen" or a variation thereof (in honor of the late great Dr. Gould.) That excludes 99% of the population.*
But even counting only 1% of the folks who we would statistically expect to sign it, the second petition has more signatures in absolute numbers than the first.
*Think of it as the scientists taking on the anti-science group with not only one hand tied behind their backs, but 99% of their body tied behind their backs...