English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The extent and nature of genetic incompatibilities between incipient races and sibling species is of fundamental importance to our view of speciation. However, with the exception of hybrid inviability and sterility factors, little is known about the extent of other, more subtle genetic incompatibilities between incipient species. Here we experimentally demonstrate the prevalence of such genetic incompatibilities between two young allopatric sibling species,  Drosophila simulans  and  D. sechellia . Our experiments took advantage of 12 introgression lines that carried random introgressed  D. sechellia  segments in different parts of the  D. simulans  genome. First, we found that these introgression lines did not show any measurable sterility or inviability effects. To study if these  sechellia  introgressions in a  simulans  background contained other fitness consequences, we competed and genetically tracked the marked alleles within each introgression against the wild-type alleles for 20 generations. Strikingly, all marked  D. sechellia  introgression alleles rapidly decreased in frequency in only 6 to 7 generations. We then developed computer simulations to model our competition results. These simulations indicated that selection against  D. sechellia  introgression alleles was high (average  s  = 0.43) and that the marker alleles and the incompatible alleles did not separate in 78% of the introgressions. The latter result likely implies that most introgressions contain multiple genetic incompatibilities. Thus, this study reveals that, even at early stages of speciation, many parts of the genome diverge to a point where introducing foreign elements has detrimental fitness consequences, but which cannot be seen using standard sterility and inviability assays.

Incompatibility and Competitive Exclusion of Genomic Segments between Sibling Drosophila Species