Thursday, October 8, 2009
The Brain: No Evidence for Lineal Descent
Neuroscientist and evolutionist Paul Patton made an interesting revelation, at least for me:
“One of the most common misconceptions about brain evolution is that it represents a linear process culminating in amazing cognitive powers of humans, with brains of other modern species representing previous stages…However research in comparative neuron-anatomy clearly has shown that complex brains—and sophisticated cognition—have evolved from simpler brains multiple times independently in separate lineages.” (Scientific America Mind, “One World, Many Minds,” Dec 2008/Jan 2009, 72-73)
Patton acknowledges that what had been promoted as the evolutionary pathway of the brain (from simplicity to complexity), is not so. Previously, it had been taught that our brains derived from four sequential evolutionary steps in which the fish brain was overlaid by a reptilian complex and later repackaged in over-lying paleo- and then neo-mammalian brain additions:
“A ‘neural chassis” corresponding to the brains of fish and amphibians; a reptilian complex, consisting of the basal ganglia, which were held to dominate the brains of reptiles and birds; a paleomammalian component, consisting of the brains limbic system, which supposedly emerged with the origin of mammals and which was responsible for emotional behavior; and finally a neomammalian component, consisting of the neocortex, the site of higher cognitive function.” (75)
What does this say about the common brain structures that had confidently cast fish as our ancestors?
“In recent decades scientists have cast aside a linear, sequential view of brain evolution in which the human brain incorporated components resembling the brains of modern fish, amphibians, reptiles and birds.” (79)
What then explains the similar inter-phyla brain “components” if not a “linear, sequential…brain evolution?” Not much, if they evolved “independently in separate lineages!” This would seem to be major bad news for the Darwinist. Traditionally and necessarily, they have argued their case by virtue of homology—common structures suggest common ancestry! However, common structures fail to necessarily argue for common descent.
Another example of this is flight. Darwinists admit that insects, reptiles, birds and mammals had all taken to the skies evolutionarily independent of each other. Now they are admitting the same about the brain. However, their case for common ancestry by virtue of the common brain structures had been particularly impressive. We had been led to believe that the theory of evolution was not only established by homology but also by the fact that the more recent species had gradually added additional brains structures upon the old, one on top of the preceding structure like building a house—the frame built upon the foundation; the roof on the frame, each requiring the prior structure. Not so!
Genetics has become the Darwinists’ Alamo. It’s there that they are making their last-stand. However, the reasoning is still the same: common genetics proves common descent! But this reasoning has consistently failed to demonstrate a common ancestry instead of a common Designer.