You are currently browsing the tag archive for the ‘exaptation’ tag.
I COVERED the volvocine algae recently and promised a post on some of the genes involved in the evolution of multicellularity in this group. We still know relatively little about the genomes of volvocine algae, but research has picked out three genes involved in the evolution of multicellularity. These are invA, glsA, and regA.
IN MANY CASES even large phenotypic changes can occur without much genetic change. However, occasionally a species will be placed in a situation in which its ancestor’s genes are insufficient, and if the species possesses a gene that can be co-opted into a new role, selection can favor evolution of new genes and a corresponding radiation of species. The Pieridae family of butterflies lay their eggs on plants in the Brassicaceae family, which contains mustards and cabbages. These plants have evolved to produce compounds that are harmless in undamaged leaves, but when a leaf is damaged are converted to a potent insecticide. The pierids evolved a deactivating protein that diverts the chemical reaction to produce nontoxic products. This gene evolved shortly after the plants themselves, and would have allowed these butterflies’ larvae to feed upon these plants with little competition.