The Social Gene

SynopsisSkew selection is a multiple-selection model (not to be confused with a multi-level selection model) that explains the inherent duality of social behavior from an individualistic, self-preservation point of view. The dual behaviors of social beings are ‘greed’ and ‘sharing’. Greed produces resource stockpiles. Stockpiles buffer an individual from famine. Sharing aggregates individuals into groups. Groups buffer an individual from predation through safety-in-numbers. In this paper, skew selection is applied to genes as a potential solution for two genomic puzzles: (1) junk DNA; and (2) the C-value enigma. Junk DNA refers to the large number of non-coding DNA sequences within a genome. Skew selection hypothesizes that, when genes are exposed to agents of predation such as point mutations, viral infections or chromosomal crossovers, genes that share resources with a large number of junk DNA sequences will survive longer than genes that do not share. The C-value enigma refers to the lack of relationship between genomic size and animal complexity. Skew selection hypothesizes that genomic size and animal complexity evolve independently of each other. Genomic size (i.e., junk DNA) shields genes from agents of mutation, viruses or chromosomal crossovers. Animal complexity (i.e., gene diversity) buffers genes from resource scarcity by allowing organisms to exploit diverse resources. In conclusion, by viewing gene survival through the lens of skew selection, molecular biologists gain insight into the evolution of genomic size and animal complexity as independent survival strategies of self-interested genes facing multiple agents of selection.