Researchers have identified and categorized the effect of two genes on the mating behavior of the majority of ape species that are not human in a report at the Public Library of Science web site on December 27, 2011.
The researchers conclude that these genes are responsible for the lack of monogamy in most ape species.
Extension of the same analysis to man should be very revealing to both psychology and religion as both seem to have predicated their arguments for monogamy or the lack of monogamy on theoretical argument rather than genetic proof.
We have previously demonstrated that the Y-specific ampliconic fertility genes DAZ (deleted in azoospermia) and CDY (chromodomain protein Y) varied with respect to copy number and position among chimpanzees (Pan troglodytes). In comparison, seven Y-chromosomal lineages of the bonobo (Pan paniscus), the chimpanzee’s closest living relative, showed no variation. We extend our earlier comparative investigation to include an analysis of the intraspecific variation of these genes in gorillas (Gorilla gorilla) and orangutans (Pongo pygmaeus), and examine the resulting patterns in the light of the species’ markedly different social and mating behaviors.
Fluorescence in situ hybridization analysis (FISH) of DAZ and CDY in 12 Y-chromosomal lineages of western lowland gorilla (G. gorilla gorilla) and a single lineage of the eastern lowland gorilla (G. beringei graueri) showed no variation among lineages. Similar findings were noted for the 10 Y-chromosomal lineages examined in the Bornean orangutan (Pongo pygmaeus), and 11 Y-chromosomal lineages of the Sumatran orangutan (P. abelii). We validated the contrasting DAZ and CDY patterns using quantitative real-time polymerase chain reaction (qPCR) in chimpanzee and bonobo.
High intraspecific variation in copy number and position of the DAZ and CDY genes is seen only in the chimpanzee. We hypothesize that this is best explained by sperm competition that results in the variant DAZ and CDY haplotypes detected in this species. In contrast, bonobos, gorillas and orangutans—species that are not subject to sperm competition—showed no intraspecific variation in DAZ and CDY suggesting that monoandry in gorillas, and preferential female mate choice in bonobos and orangutans, probably permitted the fixation of a single Y variant in each taxon. These data support the notion that the evolutionary history of a primate Y chromosome is not simply encrypted in its DNA sequences, but is also shaped by the social and behavioral circumstances under which the specific species has evolved.
Y-Chromosome Variation in Hominids: Intraspecific Variation Is Limited to the Polygamous Chimpanzee
Gabriele Greve1¤, Evguenia Alechine1,2, Juan J. Pasantes1,3, Christine Hodler1, Wolfram Rietschel4, Terence J. Robinson5, Werner Schempp1*
1 Institute of Human Genetics, University of Freiburg, Freiburg, Germany, 2 Servicio de Huellas Digitales Genéticas, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina, 3 Department of Biochemistry, Genetics and Immunology, University of Vigo, Vigo, Spain, 4 Wilhelma der Zoologisch Botanische Garten, Stuttgart, Germany, 5 Evolutionary Genomics Group, Department of Botany and Zoology, University of Stellenbosch, Stellenbosch, South Africa
Citation: Greve G, Alechine E, Pasantes JJ, Hodler C, Rietschel W, et al. (2011) Y-Chromosome Variation in Hominids: Intraspecific Variation Is Limited to the Polygamous Chimpanzee. PLoS ONE 6(12): e29311. doi:10.1371/journal.pone.0029311