Meeting Abstract
Polyploids are organisms with more than two sets of homologous chromosomes. Polyploids may experience fitness advantages over their diploid counterparts due to increased benefits from effects such as heterosis (hybrid vigor) and gene redundancy. However, as polyploid individuals are formed spontaneously, matings between them are statistically unlikely. Additionally, if matings occur between polyploids and diploids the resulting offspring will be unviable, and as a result it is unlikely to see diploids and polyploids occurring sympatrically. To explore these ideas, we collected 5,660 observations from 75 species across the 5 South American frog genera with verified polyploid members. We recovered a negative correlation between polyploid and diploid occurrences as well as close spatial associations in polyploids across genera. Where diploids are distributed throughout South America, polyploid species are clustered by the Southeastern coast between 40-10oS. This region covers much of the Atlantic forest and shares considerable overlap with the South American dry diagonal. These biomes are hypothesized to have played important roles in maintaining biodiversity over evolutionary time, in addition to being modern day biodiversity “hot-spots”. We also recover some evidence to suggest the observed trend may be the result of more recent anthropogenic influences. Polyploids are positively correlated with areas of high pollution from agricultural runoff, whereas diploids are negatively correlated. Similarly, polyploids are more likely than diploids to occur in areas of high human impact such as croplands, pastures, and urbanized environments. Exploring genomic data from these genera may further elucidate evolutionary dynamics between diploids and polyploids and unlock the secrets of polyploid genomes.
