Sunday, June 21, 2009

Scientific American: Origins of the Left & Right Brain

Another month, another classic Scientific American entry in the evolution genre. In this July issue, amongst a set of scientific articles on economics, energy, antibiotics and space exploration, is an article on the evolution of the left and right hemispheres of the brain.

The article, written by three evolutionists, explains that it was once thought that the hemispheric specialization of our brain (e.g., language in the left hemisphere, spatial thinking in the right hemisphere) evolved in our hominid ancestors, over the past few million years. But it now appears to have evolved orders of magnitude farther back in time.

Why the half a billion year change? Mainly because of the accumulation of evidence of hemispheric specialization in a wide array of species. "So what" you ask?

If you want to make sense of the evolution genre you must understand that when similarities are discovered between species, evolutionists will think the similarities must have come from a common ancestor. (Unless, that is, if the arrangement would violate other similarities, which, much to the evolutionist's chagrin, often seems to be the case eventually--see below). If hemispheric specialization is found in different species, then it must have derived from their common ancestor, which takes us back to about half a billions years ago.

For instance, right-handedness has been found in various primates. Amazingly, yet true to form, the evolutionists claim that this clearly suggests "that human right-handedness descended from that of earlier primates."

Next add hemispheric specialization findings in birds, the sea lion, and in other species, and evolutionists must conclude that such profound complexity dates back to the early branches of the evolutionary tree. This is a common trend, and today evolutionists must believe that incredibly complex designs mysteriously arose in the earliest stages of evolution.

But what about those species that contradict the hemispheric specializations? This is another common problem for evolution. Evolutionists try to organize the species by their differences and similarities, but the divisions are never clean. Neighboring species have profound differences and distant species share profound similarities. The species do not naturally form an evolutionary tree. Evolution's solution to this dilemma is to count the cooperative comparisons as indicative of evolutionary history, and to discard the non cooperative comparisons as anomalies. True to form, the evolutionists describe the contradictions to their hemispheric specialization groupings as "exceptions."

As is typical of the evolution genre, the article is packed with just-so stories, and hypotheticals. Here are few examples:

In early vertebrates such a division of labor probably got its start when one or the other hemisphere developed a tendency to take control in particular circumstances ...

In all vertebrate classes ... animals tend to retain what was probably an ancestral bias toward the use of the right side in the routine activity of feeding ...

The syllable may have evolved as a by-product of the alternate raising (consonant) and lowering (vowel) of the mandible, a behavior already well established for chewing, sucking and licking. A series of these mouth cycles, produced as lip smacks, may have begun to serve among early humans as communication signals, just as they do to this day among many other primates.

Somewhat later the vocalizing capabilities of the larynx could have paired with the communicative lip smacks to form spoken syllables.

The article ends with a classic tautology, with otherwise straightforward observations gratuitously ascribed to evolution:

For example, one would expect schooling fish to have evolved mostly uniform turning preferences, the better to remain together as a school. Solitary fish, in contrast, would probably vary randomly in their turning preferences, because they have little need to swim together. This is in fact the case.

Religion drives science, and it matters.