Abstract
Reproductive isolation can be initiated by changes in one or a few key traits that prevent random mating among individuals in a population. During the early stages of speciation, when isolation is often incomplete, there will be a heterogeneous pattern of differentiation across regions of the genome between diverging populations, with loci controlling these key traits appearing the most distinct as a result of strong diversifying selection. In this study, we used Illumina-sequenced ddRAD tags to identify genomewide patterns of differentiation in three recently diverged island populations of the Monarcha castaneiventris flycatcher of the Solomon Islands. Populations of this species have diverged in plumage colour, and these differences in plumage colour, in turn, are used in conspecific recognition and likely important in reproductive isolation. Previous candidate gene sequencing identified point mutations in MC1R and ASIP, both known pigmentation genes, to be associated with the difference in plumage colour between islands. Here, we show that background levels of genomic differentiation based on over 70,000 SNPs are extremely low between populations of distinct plumage colour, with no loci reaching the level of differentiation found in either candidate gene. Further, we found that a phylogenetic analysis based on these SNPs produced a taxonomy wherein the two melanic populations appear to have evolved convergently, rather than from a single common ancestor, in contrast to their original classification as a single subspecies. Finally, we found evidence that the pattern of low genomic differentiation is the result of both incomplete lineage sorting and gene flow between populations.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 3760-3774 |
| Number of pages | 15 |
| Journal | Molecular Ecology |
| Volume | 26 |
| Issue number | 14 |
| DOIs | |
| State | Published - Jul 1 2017 |
Fingerprint
Keywords
- convergent evolution
- ddRAD sequencing
- divergence
- Monarcha
- speciation with gene flow
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Genetics
Cite this
Genomic evidence for convergent evolution of a key trait underlying divergence in island birds. / Cooper, Elizabeth A.; Uy, J. Albert.
In: Molecular Ecology, Vol. 26, No. 14, 01.07.2017, p. 3760-3774.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Genomic evidence for convergent evolution of a key trait underlying divergence in island birds
AU - Cooper, Elizabeth A.
AU - Uy, J. Albert
PY - 2017/7/1
Y1 - 2017/7/1
N2 - Reproductive isolation can be initiated by changes in one or a few key traits that prevent random mating among individuals in a population. During the early stages of speciation, when isolation is often incomplete, there will be a heterogeneous pattern of differentiation across regions of the genome between diverging populations, with loci controlling these key traits appearing the most distinct as a result of strong diversifying selection. In this study, we used Illumina-sequenced ddRAD tags to identify genomewide patterns of differentiation in three recently diverged island populations of the Monarcha castaneiventris flycatcher of the Solomon Islands. Populations of this species have diverged in plumage colour, and these differences in plumage colour, in turn, are used in conspecific recognition and likely important in reproductive isolation. Previous candidate gene sequencing identified point mutations in MC1R and ASIP, both known pigmentation genes, to be associated with the difference in plumage colour between islands. Here, we show that background levels of genomic differentiation based on over 70,000 SNPs are extremely low between populations of distinct plumage colour, with no loci reaching the level of differentiation found in either candidate gene. Further, we found that a phylogenetic analysis based on these SNPs produced a taxonomy wherein the two melanic populations appear to have evolved convergently, rather than from a single common ancestor, in contrast to their original classification as a single subspecies. Finally, we found evidence that the pattern of low genomic differentiation is the result of both incomplete lineage sorting and gene flow between populations.
AB - Reproductive isolation can be initiated by changes in one or a few key traits that prevent random mating among individuals in a population. During the early stages of speciation, when isolation is often incomplete, there will be a heterogeneous pattern of differentiation across regions of the genome between diverging populations, with loci controlling these key traits appearing the most distinct as a result of strong diversifying selection. In this study, we used Illumina-sequenced ddRAD tags to identify genomewide patterns of differentiation in three recently diverged island populations of the Monarcha castaneiventris flycatcher of the Solomon Islands. Populations of this species have diverged in plumage colour, and these differences in plumage colour, in turn, are used in conspecific recognition and likely important in reproductive isolation. Previous candidate gene sequencing identified point mutations in MC1R and ASIP, both known pigmentation genes, to be associated with the difference in plumage colour between islands. Here, we show that background levels of genomic differentiation based on over 70,000 SNPs are extremely low between populations of distinct plumage colour, with no loci reaching the level of differentiation found in either candidate gene. Further, we found that a phylogenetic analysis based on these SNPs produced a taxonomy wherein the two melanic populations appear to have evolved convergently, rather than from a single common ancestor, in contrast to their original classification as a single subspecies. Finally, we found evidence that the pattern of low genomic differentiation is the result of both incomplete lineage sorting and gene flow between populations.
KW - convergent evolution
KW - ddRAD sequencing
KW - divergence
KW - Monarcha
KW - speciation with gene flow
UR - http://www.scopus.com/inward/record.url?scp=85018578629&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85018578629&partnerID=8YFLogxK
U2 - 10.1111/mec.14116
DO - 10.1111/mec.14116
M3 - Article
C2 - 28370617
AN - SCOPUS:85018578629
VL - 26
SP - 3760
EP - 3774
JO - Molecular Ecology
JF - Molecular Ecology
SN - 0962-1083
IS - 14
ER -