10.5061/DRYAD.B2RBNZSB1
Fang, Bohao
0000-0001-5283-067X
University of Helsinki
Kemppainen, Petri
University of Helsinki
Momigliano, Paolo
University of Helsinki
Feng, Xueyun
University of Helsinki
Merilä, Juha
University of Helsinki
On the causes of geographically heterogeneous parallel evolution in
sticklebacks
Dryad
dataset
2020
Gasterosterus aculeatus
three-spined stickleback
Parallel evolution
FOS: Biological sciences
Academy of Finland
https://ror.org/05k73zm37
250435
Academy of Finland
https://ror.org/05k73zm37
263722
Academy of Finland
https://ror.org/05k73zm37
265211
Academy of Finland
https://ror.org/05k73zm37
1307943
Academy of Finland
https://ror.org/05k73zm37
316294
Finnish Cultural Foundation*
00190489
China Scholarship Council
https://ror.org/04atp4p48
201606270188
Finnish Cultural Foundation
190489
2020-05-01T00:00:00Z
2020-05-01T00:00:00Z
en
https://doi.org/10.1038/s41559-020-1222-6
1370384675 bytes
9
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
The three-spined stickleback (Gasterosteus aculeatus) is an important
model system for the study of parallel evolution in the wild, having
repeatedly colonized and adapted to freshwater from the sea throughout the
northern hemisphere. Previous studies identified numerous genomic regions
showing consistent genetic differentiation between freshwater and marine
ecotypes but these had typically limited geographic sampling and mostly
focused on the Eastern Pacific region. We analysed population genomic data
from global samples of the three-spined stickleback marine and freshwater
ecotypes to detect loci involved in parallel evolution at different
geographic scales. Most signatures of parallel evolution were unique to
the Eastern Pacific and trans-oceanic marine–freshwater differentiation
was restricted to a limited number of shared genomic regions, including
three chromosomal inversions. On the basis of simulations and empirical
data, we demonstrate that this could result from the stochastic loss of
freshwater-adapted alleles during the invasion of the Atlantic basin and
selection against freshwater-adapted variants in the sea, both of which
can reduce standing genetic variation available for freshwater adaptation
outside the Eastern Pacific region. Moreover, the elevated linkage
disequilibrium associated with marine–freshwater differentiation in the
Eastern Pacific is consistent with secondary contact between marine and
freshwater populations that evolved in isolation from each other during
past glacial periods. Thus, contrary to what earlier studies from the
Eastern Pacific region have led us to believe, parallel marine–freshwater
differentiation in sticklebacks is far less prevalent and pronounced in
all other parts of the species global distribution range.