Convergent evolution in human and domesticate adaptation to high-altitude environments

Abstract

Humans and their domestic animals have lived and thrived in high-altitude environments worldwide for thousands of years. These populations have developed a number of adaptations to survive in a hypoxic environment, and several genomic studies have been conducted to identify the genes that drive these adaptations. Here, we discuss the various adaptations and genetic variants that have been identified as adaptive in human and domestic animal populations and the ways in which convergent evolution has occurred as these populations have adapted to high-altitude environments. We found that human and domesticate populations have adapted to hypoxic environments in similar ways. Specific genes and biological pathways have been involved in high-altitude adaptation for multiple populations, although the specific variants differ between populations. Additionally, we found that the gene EPAS1 is often a target of selection in hypoxic environments and has been involved in multiple adaptive introgression events. High-altitude environments exert strong selective pressures, and human and animal populations have evolved in convergent ways to cope with a chronic lack of oxygen. This article is part of the theme issue 'Convergent evolution in the genomics era: new insights and directions'.

Keywords: convergent evolution; domestication; high altitude; human adaptation.

Figure 1.

A map summarizing the genomic studies done on human and domesticate populations at high altitude, highlighting the convergent evolution between populations. The three high-altitude regions are highlighted, and the human and animal icons show the different species that have been studied in each region. Lines connecting populations indicate adaptation in the same or similar genes—solid lines indicate adaptation in the same gene, with EPAS1 highlighted in red, and dashed lines indicate similar genes that show adaptation across multiple populations. Pig and sheep icons from icons8.com, cow icon by Olivier Guin from thenounproject.com, chicken icon and goat icon by tan from onlinewebfonts.com and human icon by Dave Gandy from fontawesome.io, used under Creative Commons.

Figure 2.

A summary of the GO terms shared between high-altitude populations. (a) The pairwise counts of all GO terms shared between populations. (b) The pairwise counts of common GO terms (found in at least half of the high-altitude populations sampled) shared between populations. Tibetan Horses are omitted from (b) because they did not have any of the common GO terms. (Online version in colour.)