D. L. Powell

Recent evolution of large offspring size and post-fertilization nutrient provisioning in swordtails

This study compares reproductive strategies between two swordtail fish species, finding that X. malinche produces larger, more resilient offspring through extended post-fertilization nutrient provisioning.

Pervasive gene flow despite strong and varied reproductive barriers in swordtails

This study shows that despite strong reproductive barriers, gene flow is pervasive between closely related swordtail fish species through hybridization and genetic incompatibilities.

Genome evolution is surprisingly predictable after initial hybridization

The paper shows that local ancestry in hybrid swordtail fish populations is repeatable due to strong early selection, and this repeatability increases with deeper evolutionary divergence.

Recurrent evolution of small body size and loss of the sword ornament in Northern Swordtail fish

The paper uses whole-genome sequencing to resolve phylogenetic relationships in Xiphophorus fish, revealing recurrent loss of sexually selected traits like body size and sword ornaments.

Complex hybridization between deeply diverged fish species in a disturbed ecosystem

The paper develops a tool for ancestry inference in three-way hybrids and reports a complex hybridization event between three swordtail fish species linked to anthropogenic disturbance.

A widely-used pollutant causes reversal of conspecific mate preference in a freshwater fish

This study shows that calcium hydroxide pollution reverses mate preference in swordtail fish, promoting hybridization between species.

A Lethal Genetic Incompatibility between Naturally Hybridizing Species in Mitochondrial Complex I

The paper identifies a lethal mitonuclear incompatibility in swordtail fish hybrids involving three Complex I genes, showing non-additive genetic effects and inter-species transfer of incompatibility.

Predictability and parallelism in the contemporary evolution of hybrid genomes

The paper examines repeatability in local ancestry across hybrid swordtail fish populations and identifies shared genomic regions under selection.

Two new hybrid zones expand the swordtail hybridization model system

The paper identifies two genetically distinct subpopulations in swordtail fish hybrid zones, suggesting strong assortative mating and limited gene flow.

The genetic architecture of the sexually selected sword ornament and its evolution in hybrid populations

The paper investigates the genetic architecture of a sexually selected sword ornament in swordtail fish, identifying a major QTL and candidate genes, and finding evidence of selection against the trait in hybrid populations.

Natural hybridization reveals incompatible alleles that cause melanoma in swordtail fish

Using a combination of mapping approaches, we identify interacting genes that lead to melanoma in hybrids and characterize their effects in natural hybrid populations.