Genomic consequences of artificial introduction, expansion and population replacement in the Trinidadian guppy

Evolutionary biologists have been fascinated for years by questions about the reasons for the accumulation of harmful mutations and the processes that facilitate the accumulation of beneficial variants.In this project, we took a closer look at the process of potential accumulation of harmful mutations in a spreading population. In order to study this process in real time, we have decided to examine the population of guppies, which was artificially introduced into one of the rivers in Trinidad 60 years ago. Since then, the population has rapidly grown and practically colonized the entire river area, creating an interesting model to study the effects of expansion.By studying the entire genomes of fish, we want to answer the question of whether they accumulate harmful mutations as a result of expansion in a manner consistent with theoretical models built for human populations. The second issue we intend to explore concerns adaptive potential, or the ability to accumulate beneficial mutations. This potential may be related to the crossing of closely related species. Using the analogy again to the history of the human population, such a process occurred when modern humans colonized new territories, encountering Neanderthals.Guppy populations provide a good model for studying such processes as well. In the mentioned river where artificially introduced guppies are spreading, there were previously individuals of a closely related species. Both species can interbreed and produce fertile offspring. The question remains open as to how freely genes can flow between these species and whether it may be related to the incorporation of beneficial mutations into the genetic pool. By analyzing the genomes of the studied organisms, we want to answer these questions.By studying the introduced population of Trinidad guppies, we aim to contribute to understanding the fundamental evolutionary processes that may have been crucial for the evolution of many populations, including the evolution of the human population.