Cellular Mechanisms Explain Differences in Species Biology and Help Us Understand Their Evolution
Published:24 Nov.2022 Source:University of Eastern Finland
The evolutionary lineages of the brown hare and the mountain hare separated about three million years ago. The mountain hare evolved in the Beringian region and its closest relatives live in the Americas and in the Far East. In contrast, the brown hare evolved in the Near East or the Caspian region, and its closest modern relatives live in Africa and the Near East. As a consequence of their different evolutionary trajectories, the mountain hare is a cold- and snow-adapted, a Taiga Forest and an arctic species, whereas the brown hare is a more temperate, open bushland-adapted species. Besides these habitat differences, the two species differ in many other aspects of their biology.
These differences have evolved during millions of years of natural selection resulting in genomic differences. When studying cell lines from four brown hares and four mountain hares, the researchers noticed fundamental differences in the regulation of several gene groups. Some of these enabled brown hare cells to proliferate faster than mountain hare cells, which correlated with how the species age and reach maturity. There were also differences in energy metabolism, which together with cell cycle regulation demonstrate how the two species differ in their investment of resources for various features of their basic cell functions. The same differences in the investment of resources are likely to be reflected in the ageing and reproduction of the two species.