In order to keep this post as short as possible, I provide links from this post to two of the most accessible and useful online sources of information on evolution: Wikipedia and the Talk Origins Archive. Links to the Talk Origins pages use a small (TO). All other links in this section are to Wikipedia articles. Please follow them for substantiation of my claims.
The scientific consensus on the basics of evolution is sound. It is based on mountains of empirical evidence, including molecular (genetic) evidence, comparative physiology and geographical distributions, and fossil evidence.
Even so, some people - particularly members of certain religious groups - remain unpersuaded. Blanchard is one of those people.
At one level, the existence of a god is a completely separate question from the manner in which life has developed over Earth's history. So for someone to raise the topic of evolution in an argument against atheism means one of two things: either they believe in a conception of a god that conflicts with the physical evidence on which evolutionary theory is based, or they have an impression of the theory of evolution as something other than what it actually is. Or both.
It's clear early on that Blanchard is guilty of at least the second error:
No longer limited to biology, evolution has become a total philosophy which claims to explain the origin and development of everything within a closed universe, and thereby to rule out the existence of God. (p83)
No, no, and no.
No, the theory of biological evolution that got its start with Darwin and Wallace has not become a philosophy, nor come to encompass other disciplines. It remains a theory about how species change over time. Other uses of the term evolution in science include chemical evolution (abiogenesis) (TO), stellar evolution, and galaxy formation and evolution. These are separate topics; the evidence supporting them is largely separate from the evidence supporting (biological) evolution.
No, none of these theories, either individually or taken together, explains the origin and development of everything. That is one of the goals of science, but no credible scientist claims to have achieved it yet.
And no, sciences do not rule out the existence of God (TO). They may, in their progress, disprove (or cast reasonable doubt on) certain claims made by humans on behalf of God - such as a geocentric universe, a young Earth, separate creation of similar species, and so forth. And of course, people can extrapolate beyond the science. Dawkins points out that "Darwin made it possible to be an intellectually fulfilled atheist," because it revealed an alternative to the argument from design.
Blanchard goes on to present misleading arguments that are tiresomely familiar to those who care to learn about evolution.
For example, he describes Piltdown Man (TO) and Nebraska Man (TO) - famous hoax fossils. He plays down the fact that it was scientists, judging the evidence in light of evolutionary theory, who established them as hoaxes. With these and other examples, Blanchard declares that the fossil evidence is not enough to establish common descent.
I suspect he's wrong, but whether he is or not, there's a far more obvious flaw in his reasoning.
He's implying that fossils are the crucial evidence for evolution. They aren't. They never have been. In the The Origin of Species, Darwin focused on morphological patterns of relatedness and geographical distribution in modern species and genera (see here and here) - patterns which remain unexplained except in the light of common descent. Modern biologists spend much of their time with molecules: the genetic code confirms patterns of descent predicted by Darwin's earlier methods.
Fossils are wonderful. They invariably support an evolutionary explanation of species development. And, in showing what animals (and occasionally plants) actually looked like, they satisfy human desires for a physical manifestation of the past. But organisms only fossilize under particular, rare conditions (TO). So we expect "gaps". Even Darwin was aware of them, and (correctly) didn't feel they undermined his argument. Fossils neither make nor break evolutionary theory; they simply support it.
In summary, Blanchard colossally fails to demonstrate a basic knowledge of why evolution is accepted by biologists. Without that knowledge, he has no hope of persuading a moderately-informed audience that there are deep flaws in evolutionary theory.
So far, he's failing to engage this atheist; he's just making me seriously doubt the rigour of his research.
Next up: Does Blanchard understand humanism?