We examined the genetic diversity on a microgeographic scale of Rhinichthys atratulus (Eastern Blacknose Dace) in Allyn Brook, a small tributary in the upper Coginchaug River drainage in Connecticut. By looking at gen...We examined the genetic diversity on a microgeographic scale of Rhinichthys atratulus (Eastern Blacknose Dace) in Allyn Brook, a small tributary in the upper Coginchaug River drainage in Connecticut. By looking at gene flow on a microgeographic scale among populations that had no physical barriers to migration, we tested the null hypothesis that the populations should be homogeneous. We resolved seven polymorphic microsatellite loci and one mitochondrial gene, nd2, in three adjacent populations (<0.5 km) in Allyn Brook and compared these populations to the two closest populations (>5 km) in the Coginchaug River. A dam from the 1920’s in lower Allyn Brook has isolated Allyn-Brook populations from Coginchaug-River populations. Allyn Brook was selected because there are only three riffle habitats in the brook and, therefore, there can be no immigration from upstream populations. Each population has private (i.e., unique) alleles and haplotypes, and there are significant genetic differences between all sites. The Allyn Brook populations are almost as different from one another as they are from the distant populations in the Coginchaug River from which they have been isolated for more than 80 years. These results point to in situ evolution and little migration or gene flow among populations on a microgeographic scale. This raises interesting questions for conservation of genetic diversity of stream fishes.展开更多
Many bird species are known to differ in their vocal repertoires between populations across a range of geographic scales.This is generally assumed to be caused by acoustic drift and social learning of small difference...Many bird species are known to differ in their vocal repertoires between populations across a range of geographic scales.This is generally assumed to be caused by acoustic drift and social learning of small differences in songs among individuals in separate populations.To determine the extent to which vocal repertoire is structured in a highly nomadic species with a low degree of isolation among populations,we characterized the vocalizations of the'Apapane(Himatione sanguinea)and described the variations in its songs on a microgeographic scale.'Apapane had significant shifts in their songs in both fragmented and non-fragmented forest habitats,with little to no overlap in song meme structure within distances as short as 2 km,despite birds moving freely between areas with distinct songs.Forest fragments had unique song compositions and shared more syllables with closer fragments than with the ones further apart.Furthermore,microgeographic variation was relatively stable at a given recording location even over multiple years.This pattern of song differentiation in a highly mobile species at the microgeographic scale may be a consequence of their ability to learn new vocalizations over their life and of intraspecific mimicry,or“vocal matching”by individuals visiting other populations.展开更多
文摘We examined the genetic diversity on a microgeographic scale of Rhinichthys atratulus (Eastern Blacknose Dace) in Allyn Brook, a small tributary in the upper Coginchaug River drainage in Connecticut. By looking at gene flow on a microgeographic scale among populations that had no physical barriers to migration, we tested the null hypothesis that the populations should be homogeneous. We resolved seven polymorphic microsatellite loci and one mitochondrial gene, nd2, in three adjacent populations (<0.5 km) in Allyn Brook and compared these populations to the two closest populations (>5 km) in the Coginchaug River. A dam from the 1920’s in lower Allyn Brook has isolated Allyn-Brook populations from Coginchaug-River populations. Allyn Brook was selected because there are only three riffle habitats in the brook and, therefore, there can be no immigration from upstream populations. Each population has private (i.e., unique) alleles and haplotypes, and there are significant genetic differences between all sites. The Allyn Brook populations are almost as different from one another as they are from the distant populations in the Coginchaug River from which they have been isolated for more than 80 years. These results point to in situ evolution and little migration or gene flow among populations on a microgeographic scale. This raises interesting questions for conservation of genetic diversity of stream fishes.
基金supported by the Spanish Ministry of ScienceInnovation and Universities(MCIN/AEI/10.13039/501100011033,grant number:RYC2019-027216-I)by ESF Investing in your future。
文摘Many bird species are known to differ in their vocal repertoires between populations across a range of geographic scales.This is generally assumed to be caused by acoustic drift and social learning of small differences in songs among individuals in separate populations.To determine the extent to which vocal repertoire is structured in a highly nomadic species with a low degree of isolation among populations,we characterized the vocalizations of the'Apapane(Himatione sanguinea)and described the variations in its songs on a microgeographic scale.'Apapane had significant shifts in their songs in both fragmented and non-fragmented forest habitats,with little to no overlap in song meme structure within distances as short as 2 km,despite birds moving freely between areas with distinct songs.Forest fragments had unique song compositions and shared more syllables with closer fragments than with the ones further apart.Furthermore,microgeographic variation was relatively stable at a given recording location even over multiple years.This pattern of song differentiation in a highly mobile species at the microgeographic scale may be a consequence of their ability to learn new vocalizations over their life and of intraspecific mimicry,or“vocal matching”by individuals visiting other populations.
