What is the result of two unrelated species evolving similar traits in response to similar environmental pressures?

The phenomenon described in the question refers to two unrelated species developing similar traits due to facing comparable environmental challenges. This results in structures or adaptations that function similarly but do not share a common evolutionary origin. These adaptations are termed analogous structures.

Analogous structures arise when different species experience similar selective pressures, leading to the evolution of traits that serve similar functions, even though the species diverged from different ancestral lines. A classic example of this is the wings of bats and insects; both enable flight but evolved independently, demonstrating convergence rather than divergence.

In contrast, divergent evolution occurs when related species become more dissimilar as they adapt to different environments. Adaptive radiation refers to the rapid evolution of diversely adapted species from a common ancestor, often following the colonization of new environments. Coevolution describes the reciprocal evolutionary influences between two or more species that interact closely, such as predators and prey or parasites and hosts. These definitions clarify why the result of unrelated species evolving similar traits in response to the same environmental pressures is accurately identified as analogous structures.