Subtle introgression footprints at the end of the speciation continuum in a clade of Heliconius butterflies
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Quantifying gene flow between lineages at different stages of the speciation continuum is central to understanding speciation. Heliconius butterflies have undergone an adaptive radiation in wing color patterns driven partly by natural selection for local mimicry. Color patterns are also known to be used as assortative mating cues. Therefore, wing pattern divergence is considered to play a role in speciation. A corollary is that mimicry between closely related species may be associated with hybridization and interfere with reproductive isolation. Here, we take a multifaceted approach to explore speciation history, species boundaries, and traits involved in species differentiation between the two closely related species, Heliconius hecale and Heliconius ismenius. We focus on geographic regions where the two species mimic each other and contrast this with geographic regions where they do not mimic each other. To examine population history and patterns of gene flow, we tested and compared a four-population model accounting for linked selection. This model suggests that the two species have remained isolated for a large part of their history, yet with a small amount of gene exchange. Accordingly, signatures of genomic introgression were small except at a major wing pattern allele and chemosensing genes and stronger in the mimetic populations compared with nonmimetic populations. Behavioral assays confirm that visual confusion exists but that short-range cues determine strong sexual isolation. Tests for chemical differentiation between species identified major differences in putative pheromones which likely mediate mate choice and the maintenance of species differences.
Date Issued
2023-07
Date Acceptance
2023-07-01
Citation
Molecular Biology and Evolution, 2023, 40 (7)
ISSN
0737-4038
Publisher
Oxford University Press
Journal / Book Title
Molecular Biology and Evolution
Volume
40
Issue
7
Copyright Statement
© The Author(s) 2023. Published by Oxford University Press on behalf of Society for Molecular Biology and Evolution.
This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (https://
creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium,
provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com
This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (https://
creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium,
provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com
License URL
Identifier
https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:001039281100002&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=a2bf6146997ec60c407a63945d4e92bb
Subjects
Biochemistry & Molecular Biology
CHOICE
COURTSHIP BEHAVIOR
CUTICULAR HYDROCARBONS
EVOLUTION
Evolutionary Biology
Genetics & Heredity
HITCHHIKING
LEPIDOPTERA
Life Sciences & Biomedicine
MIMICRY
RECOMBINATION
Science & Technology
SELECTION
SEX
Publication Status
Published
Article Number
msad166
Date Publish Online
2023-07-19