Anyone who has ever bought or sold a home knows the three most important factors in real estate: location, location, location. Traditionally, geneticists did not think this principle had much to do with the variability of biological traits, but recent research now suggests otherwise. In fact, it looks as if a gene’s location is more important than its identity when it comes to the variability of biological traits.1
Knowing the relationship between gene location and trait variability will help researchers understand the genetic basis of diseases and will also help breeders develop economically useful plants and animals. This relationship also has implications for the creation/evolution controversy. Moreover, this new research makes it possible to account for a genetic feature, long touted as evidence for biological evolution, from a creation model perspective.
Genes and Biological Traits
Some biological traits, such as height, weight, etc., vary continuously within a population. These traits, determined by several genes, are called quantitative traits. Researchers want to understand where the genes that influence quantitative traits are located within chromosomes. They also want to understand the source of the genetic variability. The expectation is that the location of a gene within the chromosome should have limited influence on trait variability. Rather, natural selection and genetic drift should be the key factors that create this variation.
Location, Location, Location!
To test these ideas, a team of scientists from Princeton University determined the location of several thousand quantitative traits in the nematode Caenorhabditis elegans. They discovered that the variable traits tend to reside at the ends of chromosomes and, to a much lesser extent, near chromosomes’ center. It turns out that the identity of the gene had little to do with whether or not it displayed genetic variability. What seemed to be the most important was the gene’s location along the chromosome.
In other words, whether or not a particular biological trait varies within a population depends on its location on the chromosome, more so than anything else. This result has important implications, one of which relates to the case for biological evolution.
Gene Location and the Case for Biological Evolution
Proponents of biological evolution claim that if evolutionary processes created life’s diversity, then organisms that share a common ancestor would also share similar genomes. This similarity would not only include gene types and gene sequences, but also the physical arrangement, or ordering, of genes along a chromosome.2 But this new work suggests an alternative explanation. It could very well be that the shared ordering of genes may not reflect common ancestry but common design.
1. Matthew V. Rockman et al., “Selection at Linked Sites Shapes Heritable Phenotypic Variation in C. elegans,” Science 330 (2010): 372–76.
2. Dennis Venema and Darrel Falk, “Signature in the Synteny,” The Biologos Forum, http://biologos.org/blog/signature-in-the-synteny/, accessed October 22, 2010.