A Leanchoilia fossil from at the Qingjiang site in China. A very early arthropod found with sharply defined appendages is an arthropod and one of the prime examples of early Cambrian life (D Fu et al., Science 363:1338 (2019)
Virtually every definition of the word “life” includes the capability to undergo Darwinian evolution as a necessary characteristic. This is true of life on Earth and of thinking about what would constitute life beyond Earth. If it can’t change, the thinking goes, then it cannot be truly alive.
In addition, evolutionary selection and change occurs within the context of broad planetary systems — the chemical makeup of the atmosphere, the climactic conditions, the geochemistry and more. If an environment is changing, then the lifeforms that can best adapt to the new conditions are the ones that will survive and prosper.
So evolution is very much part of the landscape that Many Worlds explores — the search for life beyond Earth and effort to understand how life emerged on Earth. Evolution happens in the context of broad conditions on Earth (and perhaps elsewhere), and finding potential life elsewhere involves understanding the conditions on distant planets and determining if they are compatible with ...