Ryhmävalinta

Ryhmävalinta, often translated as group selection, is a concept in evolutionary biology that proposes natural selection can operate on groups of organisms as well as on individuals. In traditional evolutionary theory, selection primarily acts on the differential survival and reproduction of individuals based on their traits. Ryhmävalinta suggests that groups with certain characteristics might be more successful than other groups, leading to the evolution of traits that benefit the group as a whole, even if those traits are disadvantageous to individual members.

For example, a group of altruistic individuals might be more likely to cooperate and share resources, leading to higher group survival rates compared to a group of selfish individuals. Over time, the genes associated with altruism might become more prevalent in the population, not because altruistic individuals directly reproduce more, but because the groups they form are more successful.

However, ryhmävalinta is a controversial topic in evolutionary biology. Critics argue that individual selection is typically a much stronger force. Any individual that deviates from a group-beneficial behavior and acts selfishly might have a higher chance of reproducing, potentially undermining the spread of group-beneficial traits. Despite the debate, variations of group selection models continue to be explored and refined in theoretical biology and related fields.