A passage in Deuteronomy 14 lists some of these biblical kinds and gives us some guidance in our understanding of the various kinds. Since various species can interbreed, we can conclude that those species are from the same created kind. The division is probably somewhere around the family level in our current classification systems. Chapter 2 of Evolution Exposed: Biology explains this idea in more detail.
So, within the created kinds, we see changes in characteristics over time—or “descent with modification.” That is a commonality in the biblical and evolutionary understanding of life on earth. The disagreement comes in the amount and direction of that change.
Let’s think about the deer kind for a moment. The deer kind (family Cervidae) includes moose, elk, whitetail deer, mule deer, muntjac, fallow deer, reindeer, and many other species. This includes a wide range of sizes, colors, and antler structures.
Not So Common Descent
So evolution is accepted by AIG, even though they don't want to call it that. Here's what's holding them back from the whole truth:
So, the characteristics we see in deer around the world today were present in the genetic makeup of the deer kind aboard the Ark. Thinking about antlers as a trait, moose have palmate antlers, mule deer have tined antlers, and caribou have a mix of both. From this we can reason that the original deer kind had a mix of these features, and, over time, some species lost the genetic information to make the palmate antlers (elk and mule deer) and some species have become primarily palmate (moose). This is the kind of change that is consistent with what we find in Scripture and the kind of change I was referring to in the book.
Not So Common Descent
AIG continues to deny the observed fact that information increases in a population with every new mutation, and they assume that at one time, there was a representative of the "deer kind" with every allele now in existence in any member of the Cervidae (and their related familes). Which is just as impossible as their belief that all the alleles in humans today existed in Adam and Eve.
Lacking any understanding of genetics, they assume such a thing would be possible. In fact, Adam and Eve together, could have had no more than for alleles for each gene locus. Today many of them have hundreds of alleles. All the reset evolved.