THE MORAL ATHEIST - Can an Atheist be Consistently Pro-Life?

A Christian friend of mine challenged my continued pro-life involvement recently. He wrote:

"Just curious here. You're an agnostic/atheist type now? Is that right?

Just wondering from whence you derive your ethic for the unborn given a naturalistic/materialistic worldview.

That is: given (presumably) that you believe there is no God, or any transcendent being who created everything, and that all things came into existence by non-purposeful, random chance (ie. nothing) and that all things are evolving, hence humans are just a branch on the evolutionary tree, albeit highly complex, here through a long history of natural selection favoring our genes in death, disease, and struggle of the fittest....

WHY are human babies' lives intrinsically valuable? Why is abortion "WRONG"? And HOW, again given an atheistic worldview, in which death is final, can we expect any JUSTICE for all the lives killed from the womb???

I don't see any consistency in an atheist type getting angry about killing the unborn. Traditionally, atheists and other secularists have favored a PRO-DEATH culture of abortion, etc.

Just curious to know how you remain CONSISTENTLY pro life FROM AN ATHEIST, SECULARIST STARTING POINT."

The following was my reply:

Easy. Science makes it clear that the unborn are members of our own species. If I value my own existence and life as a human being, it only makes sense to want to see other human lives protected from harm, suffering, and wrongful death.