With all the diversity of life past and present, it’s incredible how often evolution repeats itself. Wings, flippers, eyes … all sorts of fascinating features have shown up multiple times in multiple groups of organisms. In this episode, we discuss this very common, curious, and sometimes confusing aspect of natural selection: Convergent Evolution.
Convergent evolution is a side effect of the natural processes of evolution where unrelated species end up resembling one another in behavior or morphology. Though two species may have evolved from very different ancestors, similar selective pressures can lead to them evolving very similar features (for example, birds and bats both evolved from different non-flying ancestors).
This is similar but different from parallel evolution, in which two unrelated but similar evolutionary lineages follow similar evolutionary pathways (for example,. evolving from climbing species to gliding species).
It’s very common to observe convergent evolution in species that occupy similar habitats or niches. Convergent traits are referred to as analogous structures – that is, they are similar, but evolved separately – as opposed to homologous structures, which are shared features inherited from a shared ancestor.
Not just animals!
Though convergent evolution is fascinating, it can be tricky to study and understand at times. There are even those who wonder if these numerous examples of very similar organisms actually makes a case for the limits of evolution.