Evolution is a tautology, where no matter what you see you claim that it evolved that way. It had to have done that, because nothingness to molecules to living cells to human evolution is true, right?
It reminds me of when evolutionists try to rationalize why homosexual behavior and abortion are natural and moral in an evolutionary worldview. They point to exceptions with some animals and rationalize how it helps perpetutate the species (question begging). It seems to me that these behaviors get in the way of perpetuating the species (the alleged moral good snuck in the back door as the foundation for their morality), so even in an evolutionary worldview they would be immoral.
Even if certain behaviors are observable in some animals, that hardly seems like a good standard for humans to abide by. Some dogs will attempt to procreate with anything in sight: Opposite sex dogs, same sex dogs, your leg, your coffee table, etc.
But what is amusing is their certainty. It is as if the situation were reversed and humans never had abortions or exhibited homosexual behavior that the evolutionists would be asking, “Hey, where are all the gays, lesbians, bisexuals and transgender people? Why aren’t thousands of human beings destroyed in the womb each day? We expected it to be here because of A, B and C. We know those actions aren’t immoral, so why haven’t humans figured it out?