Publications by authors named "S J Yeaman"
Global adaptation occurs when all populations of a species undergo selection toward a common optimum. This can occur by a hard selective sweep with the emergence of a new globally advantageous allele that spreads throughout a species' natural range until reaching fixation. This evolutionary process leaves a temporary trace in the region affected, which is detectable using population genomic methods.
View Article and Find Full Text PDFLocally adapted traits can exhibit a wide range of genetic architectures, from pronounced divergence at a few loci to small frequency divergence at many loci. The type of architecture that evolves depends strongly on the migration rate, as weakly selected loci experience swamping and do not make lasting contributions to divergence. Simulations from previous studies showed that even when mutations are strongly selected and should resist migration swamping, the architecture of adaptation can collapse and become transient at high mutation rates.
View Article and Find Full Text PDFLocal adaptation can cause both peaks and troughs in nucleotide diversity within populations.
G3 (Bethesda)
November 2024
Article Synopsis
- Local adaptation can have varying effects on nucleotide diversity within populations, sometimes causing reductions and other times increases, depending on factors like migration and selection strength.
- The study examines genome-wide patterns of nucleotide diversity influenced by local adaptation and finds that low migration leads to more significant diversity depletion, while high migration results in peaks of diversity over smaller genomic distances.
- The research highlights the complexity of local adaptation's influence on nucleotide diversity, indicating that there isn't a one-size-fits-all pattern, making it challenging to use nucleotide diversity as a universal marker for local adaptation.
Closely related species often use the same genes to adapt to similar environments. However, we know little about why such genes possess increased adaptive potential and whether this is conserved across deeper evolutionary lineages. Adaptation to climate presents a natural laboratory to test these ideas, as even distantly related species must contend with similar stresses.
View Article and Find Full Text PDFArticle Synopsis
- The study investigates how repeatable evolutionary changes in complex organisms contradict the Fisher-Orr model, especially when mutations affect multiple traits (pleiotropy).
- It uses simulations to analyze how fitness trade-offs and the alignment of mutation effects with spatial trait variations impact repeatability, finding that while complexity reduces repeatability, mutations with large effects still promote adaptation.
- The results indicate that repeatable adaptations are more likely in local environments with gene flow, suggesting pleiotropy's role in limiting repeatability varies with population structure.