Originally, S. invicta was believed to be a red form of the black species S. saevissima richteri Forel. In 1972, Buren described the black imported fire ant to be a separate and distinct species, S. richteri Forel, and the RIFA was identified as S. invicta Buren (Hedges 1997).
Homologous recombination is a type of genetic recombination in which nucleotide (molecules which are joined make the structural units of RNA and DNA) sequences are exchanged between two similar or identical molecules of DNA.
Recombination occurs when homologous chromosomes with different alleles exchange DNA by crossing over at a point called a chiasma. ++Remember that different alleles must be involved before crossing over can be called recombination.