scholarly journals Mixing Genetically and Morphologically Distinct Populations in Translocations: Asymmetrical Introgression in A Newly Established Population of the Boodie (Bettongia lesueur)

Genes ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 729 ◽  
Author(s):  
Rujiporn Thavornkanlapachai ◽  
Harriet R. Mills ◽  
Kym Ottewell ◽  
Judy Dunlop ◽  
Colleen Sims ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Female Mate Choice ◽  
Effective Population ◽  
Island Populations ◽  
Loop Region ◽  
D Loop ◽  
Population Sizes ◽  
Ultimate Outcome ◽  
Different Populations ◽  
Source Populations

The use of multiple source populations provides a way to maximise genetic variation and reduce the impacts of inbreeding depression in newly established translocated populations. However, there is a risk that individuals from different source populations will not interbreed, leading to population structure and smaller effective population sizes than expected. Here, we investigate the genetic consequences of mixing two isolated, morphologically distinct island populations of boodies (Bettongia lesueur) in a translocation to mainland Australia over three generations. Using 18 microsatellite loci and the mitochondrial D-loop region, we monitored the released animals and their offspring between 2010 and 2013. Despite high levels of divergence between the two source populations (FST = 0.42 and ϕST = 0.72), there was clear evidence of interbreeding between animals from different populations. However, interbreeding was non-random, with a significant bias towards crosses between the genetically smaller-sized Barrow Island males and the larger-sized Dorre Island females. This pattern of introgression was opposite to the expectation that male–male competition or female mate choice would favour larger males. This study shows how mixing diverged populations can bolster genetic variation in newly established mammal populations, but the ultimate outcome can be difficult to predict, highlighting the need for continued genetic monitoring to assess the long-term impacts of admixture.

scholarly journals Insights into human genetic variation and population history from 929 diverse genomes

2019 ◽  
Author(s):  
Anders Bergström ◽  
Shane A. McCarthy ◽  
Ruoyun Hui ◽  
Mohamed A. Almarri ◽  
Qasim Ayub ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Central Africa ◽  
Population History ◽  
Human Populations ◽  
Genome Sequences ◽  
High Coverage ◽  
Geographical Regions ◽  
History Of ◽  
Different Populations ◽  
Source Populations

AbstractGenome sequences from diverse human groups are needed to understand the structure of genetic variation in our species and the history of, and relationships between, different populations. We present 929 high-coverage genome sequences from 54 diverse human populations, 26 of which are physically phased using linked-read sequencing. Analyses of these genomes reveal an excess of previously undocumented private genetic variation in southern and central Africa and in Oceania and the Americas, but an absence of fixed, private variants between major geographical regions. We also find deep and gradual population separations within Africa, contrasting population size histories between hunter-gatherer and agriculturalist groups in the last 10,000 years, a potentially major population growth episode after the peopling of the Americas, and a contrast between single Neanderthal but multiple Denisovan source populations contributing to present-day human populations. We also demonstrate benefits to the study of population relationships of genome sequences over ascertained array genotypes. These genome sequences are freely available as a resource with no access or analysis restrictions.

scholarly journals Differentiation with drift: a spatio-temporal genetic analysis of Galápagos mockingbird populations ( Mimus spp.)

2010 ◽  
Vol 365 (1543) ◽  
pp. 1127-1138 ◽  
Author(s):  
Paquita E. A. Hoeck ◽  
Jennifer L. Bollmer ◽  
Patricia G. Parker ◽  
Lukas F. Keller
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Population Size ◽  
Genetic Drift ◽  
Bird Species ◽  
Effective Population ◽  
Island Size ◽  
Island Populations ◽  
Population Sizes ◽  
Spatio Temporal

Small and isolated island populations provide ideal systems to study the effects of limited population size, genetic drift and gene flow on genetic diversity. We assessed genetic diversity within and differentiation among 19 mockingbird populations on 15 Galápagos islands, covering all four endemic species, using 16 microsatellite loci. We tested for signs of drift and gene flow, and used historic specimens to assess genetic change over the last century and to estimate effective population sizes. Within-population genetic diversity and effective population sizes varied substantially among island populations and correlated strongly with island size, suggesting that island size serves as a good predictor for effective population size. Genetic differentiation among populations was pronounced and increased with geographical distance. A century of genetic drift did not change genetic diversity on an archipelago-wide scale, but genetic drift led to loss of genetic diversity in small populations, especially in one of the two remaining populations of the endangered Floreana mockingbird. Unlike in other Galápagos bird species such as the Darwin's finches, gene flow among mockingbird populations was low. The clear pattern of genetically distinct populations reflects the effects of genetic drift and suggests that Galápagos mockingbirds are evolving in relative isolation.

Genetic variation in the greenback flounder Rhombosolea tapirina GÜnther (Teleostei, Pleuronectidae) and the implications for aquaculture

2000 ◽  
Vol 51 (1) ◽  
pp. 23 ◽  
Author(s):  
Tony van den Enden ◽  
Robert W. G. White ◽  
Nicholas G. Elliott
Keyword(s):  
Genetic Variation ◽  
New Zealand ◽  
Genetic Distance ◽  
West Coast ◽  
Gel Electrophoresis ◽  
Effective Population ◽  
Average Heterozygosity ◽  
The West ◽  
Order Of Magnitude ◽  
Population Sizes

Samples of the greenback flounder, Rhombosolea tapirina, were collected from five Tasmanian sites and from one site each off Victoria and New Zealand. Thirty enzyme-coding loci were analysed by gel electrophoresis. Seventeen loci were variable, nine of which were polymorphic in at least four samples. Average heterozygosity across all 30 loci was relatively high at 0.086 ± 0.032. There were significant genetic differences between the Australian and New Zealand samples, with a genetic distance of 0.041, which was an order of magnitude larger than that observed between any Australian samples. Samples from the west coast of Tasmania and from Victoria were genetically isolated from each other and from the remaining four Tasmanian samples; the latter showed little variation among themselves. Reductions in genetic variation (heterozygosity and alleles) were observed in two cultured cohorts when compared with the wild-caught samples, with corresponding low estimates of effective population sizes compared with putative breeding numbers. No genetic variation was detected between normal and malpigmented individuals from the same culture cohort.

Sign in / Sign up

Export Citation Format

Share Document