Reinventing the wheel? Reassessing the roles of gene flow, sorting and convergence in repeated evolution

2021 ◽  
Author(s):  
Jonathan M. Waters ◽  
Graham A. McCulloch
Keyword(s):  
Gene Flow ◽  
Flow Sorting ◽  
Repeated Evolution

scholarly journals The role of gene flow in rapid and repeated evolution of cave-related traits in Mexican tetra,Astyanax mexicanus

2018 ◽  
Vol 27 (22) ◽  
pp. 4397-4416 ◽  
Author(s):  
Adam Herman ◽  
Yaniv Brandvain ◽  
James Weagley ◽  
William R. Jeffery ◽  
Alex C. Keene ◽  
...  
Keyword(s):  
Gene Flow ◽  
Astyanax Mexicanus ◽  
Repeated Evolution

scholarly journals Repeated evolution of reproductive isolation in a marine snail: unveiling mechanisms of speciation

2010 ◽  
Vol 365 (1547) ◽  
pp. 1735-1747 ◽  
Author(s):  
Kerstin Johannesson ◽  
Marina Panova ◽  
Petri Kemppainen ◽  
Carl André ◽  
Emilio Rolán-Alvarez ◽  
...  
Keyword(s):  
Gene Flow ◽  
Parallel Evolution ◽  
Hybrid Zones ◽  
Local Site ◽  
Rapid Spread ◽  
Repeated Evolution ◽  
Different Populations ◽  
The Uk ◽  
Candidate Loci ◽  
Selection Group

Distinct ecotypes of the snail Littorina saxatilis , each linked to a specific shore microhabitat, form a mosaic-like pattern with narrow hybrid zones in between, over which gene flow is 10–30% of within-ecotype gene flow. Multi-locus comparisons cluster populations by geographic affinity independent of ecotype, while loci under selection group populations by ecotype. The repeated occurrence of partially reproductively isolated ecotypes and the conflicting patterns in neutral and selected genes can either be explained by separation in allopatry followed by secondary overlap and extensive introgression that homogenizes neutral differences evolved under allopatry, or by repeated evolution in parapatry, or in sympatry, with the same ecotypes appearing in each local site. Data from Spain, the UK and Sweden give stronger support for a non-allopatric model of ecotype formation than for an allopatric model. Several different non-allopatric mechanisms can, however, explain the repeated evolution of the ecotypes: (i) parallel evolution by new mutations in different populations; (ii) evolution from standing genetic variation; and (iii) evolution in concert with rapid spread of new positive mutations among populations inhabiting similar environments. These models make different predictions that can be tested using comprehensive phylogenetic information combined with candidate loci sequencing.

scholarly journals The role of gene flow in rapid and repeated evolution of cave related traits in Mexican tetra, Astyanax mexicanus

2018 ◽  
Author(s):  
Adam Herman ◽  
Yaniv Brandvain ◽  
James Weagley ◽  
William R. Jeffery ◽  
Alex C. Keene ◽  
...  
Keyword(s):  
Gene Flow ◽  
Evolutionary Process ◽  
Secondary Contact ◽  
Demographic Model ◽  
Astyanax Mexicanus ◽  
Surface Population ◽  
Whole Genomes ◽  
Repeated Evolution ◽  
Blind Cave ◽  
Genomic Regions

ABSTRACTUnderstanding the molecular basis of repeated evolved phenotypes can yield key insights into the evolutionary process. Quantifying the amount of gene flow between populations is especially important in interpreting mechanisms of repeated phenotypic evolution, and genomic analyses have revealed that admixture is more common between diverging lineages than previously thought. In this study, we resequenced and analyzed nearly 50 whole genomes of the Mexican tetra from three blind cave populations, two surface populations, and outgroup samples. We confirmed that cave populations are polyphyletic and two Astyanax mexicanus lineages are present in our dataset. The two lineages likely diverged ∼257k generations ago, which, assuming 1 generation per year, is substantially younger than previous mitochondrial estimates of 5-7mya. Divergence of cave populations from their phylogenetically closest surface population likely occurred between ∼161k - 191k generations ago. The favored demographic model for most population pairs accounts for divergence with secondary contact and heterogeneous gene flow across the genome, and we rigorously identified abundant gene flow between cave and surface fish, between caves, and between separate lineages of cave and surface fish. Therefore, the evolution of cave-related traits occurred more rapidly than previously thought, and trogolomorphic traits are maintained despite substantial gene flow with surface populations. After incorporating these new demographic estimates, our models support that selection may drive the evolution of cave-derived traits, as opposed to the classic hypothesis of disuse and drift. Finally, we show that a key QTL is enriched for genomic regions with very low divergence between caves, suggesting that regions important for cave phenotypes may be transferred between caves via gene flow. In sum, our study shows that shared evolutionary history via gene flow must be considered in studies of independent, repeated trait evolution.

Great Wall blocks gene flow

Nature ◽  
2003 ◽  
Author(s):  
HelenR. Pilcher
Keyword(s):  
Gene Flow ◽  
Great Wall

Differentiation and Interrelations of Two Representatives of Laudakia stellio Complex (Reptilia: Agamidae) in Israel

2011 ◽  
Vol 4 (2) ◽  
pp. 102-114 ◽  
Author(s):  
Evgenyi N. Panov ◽  
Larissa Yu. Zykova
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Habitat Preference ◽  
Additional Data ◽  
Near East ◽  
Field Studies ◽  
Subspecies Level ◽  
Limited Gene Flow ◽  
Study Sites ◽  
And Behavior

Field studies were conducted in Central Negev within the breeding range of Laudakia stellio brachydactyla and in NE Israel (Qyriat Shemona) in the range of an unnamed form (tentatively “Near-East Rock Agama”), during March – May 1996. Additional data have been collected in Jerusalem at a distance of ca. 110 km from the first and about 170 km from the second study sites. A total of 63 individuals were caught and examined. The animals were marked and their subsequent movements were followed. Social and signal behavior of both forms were described and compared. Lizards from Negev and Qyriat Shemona differ from each other sharply in external morphology, habitat preference, population structure, and behavior. The differences obviously exceed the subspecies level. At the same time, the lizards from Jerusalem tend to be intermediate morphologically between those from both above-named localities, which permits admitting the existence of a limited gene flow between lizard populations of Negev and northern Israel. The lizards from NE Israel apparently do not belong to the nominate subspecies of L. stellio and should be regarded as one more subspecies within the species.

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