Latin Lizards: Logos vs Lottery

Today, the various species of Anolis lizard on Puerto Rico include ones small enough to forage for insects at the ends of branches, a greenish variety better able to hide in the leaves, and a brownish version well camouflaged on tree trunks and the ground. These different species likely descended from an original species that invaded the island. Just as with Darwin's finches, it is reasonable to infer that all present-day species of lizards on Puerto Rico came from a common ancestor.

The process by which these lizards adapted and specialized is not difficult to understand. Through natural selection, the lizards adapted using the genetic information already present in the original population. The ancestor Anolis lizard was most likely medium-sized and able to forage for insects both on trees and on the ground. The genetic information for both green and brown coloring was already present in varying degrees.

The splitting off of daughter populations, each with less information (as a whole population, not necessarily as individuals), does not involve the emergence of new genetic information. For a smaller number of kinds on the Ark to have given rise to the more numerous descendant species we see today, similar processes would have had to occur on a larger scale.

It becomes even more interesting when we find that the same pattern exists for Anolis lizards on the island of Jamaica. This poses a challenge for current evolutionary theory - how can evolution, which is largely considered an unguided process dependent on chance mutations, result in exactly the same paths independently? Even if the selection pressures were identical, it would still require the same chance mutations to occur over long periods of time. Could these lizards have evolved in one place and then independently migrated as separate populations to the other? Research on mitochondrial DNA suggests that this was not the case - the ancestor Anolis species on each island was somewhat different (possibly due to prior speciation in the creationist view).

However, if we assume that the genetic potential for most of these adaptive changes was already present by design, it is not surprising to find similar changes occurring. For example, if the ancestral lizard species had the genetic information enabling both green and brown coloring, then it is not unlikely for daughter species with both colors to arise, regardless of other ecological pressures (as long as there were trees). Similar arguments apply to other aspects of their adaptations.

The Anolis lizards of Puerto Rico and Jamaica are therefore more consistent with the creationist/pre-adaptationist viewpoint. Oxford zoologist Paul Harvey has even stated that "Lizards don't seem to respect evolutionary theory."

Why This Matters

The study of Anolis lizards on Puerto Rico and Jamaica provides interesting insights into the origins and diversification of species. It challenges the idea that evolution is solely based on chance mutations and demonstrates the importance of pre-existing genetic potential. This understanding aligns with a young-earth creationist perspective, where all genetic information necessary for adaptation was present from the beginning.

Think About It

1. How does the concept of pre-existing genetic potential challenge the idea of evolution as an unguided process?
2. What implications does the study of Anolis lizards have for our understanding of species diversification?
3. How does this research align with a young-earth creationist perspective?