Birds Terrorize Evolutionary Biologists
Largest Bird Study to Date Challenges the Validity of Biological Evolution
Alfred Hitchcock’s 1963 horror film The Birds broke new ground with its special effects and “revenge of nature” theme. The movie’s plot centers on vicious bird attacks that terrorize the people of Bodega Bay, a small coastal community on the shore of the Pacific Ocean.
New research on bird evolution would have delighted Hitchcock, but this work is causing horror for evolutionary biologists and raises questions about the validity of the evolutionary paradigm.*
This study represents the largest evolutionary analysis of bird relationships to date. A team of ornithologists examined the genetic variation in 169 species of birds (representing all major extant groups) using an aggregate of 32,000 base pairs (genetic letters) from 19 genetic loci.
The need for a study this large may not be obvious to most casual observers. Bird evolutionary relationships have been studied extensively. Yet, much controversy still surrounds the origin and evolutionary history of birds. A major source of the difficulty stems from the explosive diversification of modern birds when they first appear in the Tertiary period. The so-called Tertiary radiation makes resolving bird relationships (from an evolutionary perspective) intractable because all the lineages appear virtually at the same time with no intermediate forms represented among extant groups.
Using Morphology and Molecules to Construct Evolutionary Trees
Traditionally, biologists have used anatomical comparisons (morphology) to characterize evolutionary relationships and build evolutionary trees. Recent advances in DNA sequencing techniques and data analysis have now made genetic comparisons fodder for evolutionary analysis. One key expectation is that the evolutionary trees built from anatomical comparisons (morphological phylogenies) will agree with trees built from DNA sequence data (molecular phylogenies). The hope is that DNA sequence studies will provide the means to determine relationships with a greater degree of resolution. This expectation stems from the fundamental notion that molecular evolution should mirror organic evolution. In many instances, however, evolutionary biologists are discovering that molecular phylogenies contradict those built using morphological features.
Chaos Surrounds Bird Evolutionary Trees
This most recent study on bird evolutionary relationships exemplifies this conundrum. If the results of this work stand, they will force evolutionary biologists to redraw the bird evolutionary tree.
Trouble for the Evolutionary Paradigm?
This study raises significant questions about the validity of the evolutionary paradigm. First, it highlights how speculative evolutionary relationships truly are, even among groups like birds which have been extensively studied. In light of this uncertainty, it seems unwarranted for evolutionary biologists to declare evolution to be a fact.
A key idea of the evolutionary paradigm, namely that evolutionary trees built from molecules should agree with those constructed from morphology, is not supported by the evidence. This disagreement is more profound than it seems on the surface. According to Morris Goodman in an article he wrote for The Cambridge Encyclopedia of Human Evolution,
If the biblical account of creation were true, then independent features of morphology, proteins and DNA sequences would not be expected to be congruent with each other. Chaotic patterns, with different proteins and different DNA sequences failing to indicate any consistent set of species relationships, would contradict the theory of evolution.
These words were published in 1994, before the widespread use of DNA sequences to build evolutionary trees.
On the basis of Goodman’s comments and the latest work on bird evolutionary relationships alone, skepticism about the validity of the evolutionary paradigm is justified.
Like the bird attacks conceived by Hitchcock, problems for the theory of evolution seem like they never will come to an end.
*This study made science news headlines when first published. I discussed the scientific and biblical implications of this research on the June 30, 2008 edition of our podcast, RTB’s Science News Flash. This podcast offers a unique Christian perspective on headline-grabbing discoveries. A free subscription is available through iTunes.