Different biological species "broadcast" their DNAs at different (G+C)% "wavelengths".
Radio can be used as a metaphor for the transmission of information by DNA through time and space. Just as different radio transmitters broadcast at different wavelengths to prevent interference, so different biological species "broadcast" their DNAs at different (G+C)% "wavelengths" to prevent recombination. It is postulated that species differences in (G+C)% prevent recombination. First, evidence is presented supporting the early Crick-Sobell stem-loop model for genetic recombination, which proposes that the rate-limiting step in recombination is the recognition ("kissing") of complementary sequences in the loops of stem-loop structures extruded from supercoiled DNA. Then, various ways in which differences in (G+C)% might impede complementary loop interactions are outlined. The strength of the postulate is that it brings together a variety of disparate observations in fields that have not previously been seen as related. Thus, explanations are apparent for why most mutations are not selectively neutral (the "neutralist/selectionist" debate), why introns were present in the earliest genes (the "introns-early/introns-late" debate), and the origin of species.
Forsdyke
D R
DR
Department of Biochemistry, Queen's University, Kingston, Ontario, Canada. forsdyke@qcdn.queensu.ca
D000818:Animals; D005075:Biological Evolution; D003596:Cytosine / Q000378:metabolism; D004247:DNA / Q000502:physiology*; D006151:Guanosine / Q000235:genetics; D008957:Models, Genetic; D010802:Phylogeny; D013045:Species Specificity
D006151:Guanosine; D003596:Cytosine; D004247:DNA