All other trait values are under negative selection. How are humans contributing to negative selection? It's a part of evolution that can also drive some species to extinction; models of negative ...

Each species eats a different type of food ... found the offsprings' beaks to be 3 to 4% larger than their grandparents'. The Grants had documented natural selection in action.

The proportion of well-adapted organisms in a population can increase over the generations by the process of evolution by natural selection.

helsinki.fi Objectives—To investigate the associations between natural selection to sports at a young age ... male athletes participating at a young age (1920–1965) in different types of sport ...