Genetic distance in inversion polymorphism among natural populations of Drosophila ananassae

Abstract

Based on the differences in the gene arrangement frequencies average genetic distance has been estimated among natural populations of Drosophila ananassae. Genetic distance obtained by pairwise comparison ranges from 0.002 to 0.371. The most differentiated populations are those from the Andaman and Nicobar Islands. Although the populations from localities separated by a small geographic distance show less genetic distance, the relation between genetic distance and geographic distance does not seem to be positive.

Genetic similarity between natural populations of Drosophila ananassae from Kerala and Andaman and Nicobar Islands

“…The earlier results on genetic identity and distance among eight natural populations of D. ananassae have revealed that the most differentiated populations are those from the Andaman and Nicobar Islands, which were compared with the North Indian populations (Singh, 1984b). It is evident from the present I values that the Kerala populations have undergone a substantial amount of genetic divergence when compared with the populations from Uttar Pradesh, North India.…”

“…Populations from localities with frequent trade contact and having less geographic distance have been found to show less genetic identity. On the other hand, some populations which are widely separated and have less trade contact exhibit more genetic similarity (Singh, 1984b). Thus the genetic similarity between the natural populations of D. ananassae from Kerala and the Andaman and Nicobar Islands is most likely due to similarity in environmental conditions rather than due to trade contact between these localities.…”

“…Thus it is evident from the present results that the Kerala populations show less genetic identity with the North Indian populations while they have more genetic similarity with the island populations. Based on the I values presented here and reported earlier (Singh, 1984b), a dendrogram for the populations has been constructed by using the UPGMA cluster analysis method. The dendrogram is depicted in Figure 2.…”

“…This species contains numerous inversions in its natural populations (for references see Singh, 1982). By using the data on the gene arrangement frequencies in eight natural populations (Singh, 1974(Singh, , 1984a, genetic identity and distance between populations were estimated (Singh, 1984b) and the data revealed that the populations from the Andaman and Nicobar Islands have undergone a considerable degree of genetic divergence when compared with the North Indian populations. Now the data on the frequencies of different gene sequences are available for four natural populations of D. ananassae from Kerala, South India (Singh, 1984c).…”

Mating ability of homo- and heterokaryotypes of Drosophila ananassae from natural populations

“…Drosophila ananassae, a cosmopolitan domestic species, has a high degree of chromosomal variability (for references, see Singh, 1982). The Indian natural populations of this species are genetically differentiated at the level of chromosomal polymorphism (Singh, 1974(Singh, , 1984a(Singh, , 1984b(Singh, , 1984c(Singh, , 1985a(Singh, , 1985b. The subterminal (alpha or In (2L)A) inversion has become universally established in the species (Shirai and Moriwaki, 1952;Futch, 1966;Singh, 1970).…”