Convergent Evolution & Vestigial Structures

Convergent Evolution

(Comes from the word “converge”) (“come together” or “meet”)

Produces unrelated organisms that look similar to one another

The same environment will produce similar adaptations in different (unrelated) animals

FishFish MammalMammal BirdBird

Human Vestigial Structures Vestigial structures – something that no

longer does what it was evolved for On humans:

Ear muscles Wisdom teeth Appendix Tail bone Goosebumps

(Vestigial Structures) On animals:

Whales and snakes have leg bones Flightless birds still have wings Animals with non-functional eyes

Vestigial Structures, ContinuedDolphin EmbryoDolphin Embryo

Hind limb “buds”

Polydactyl horse toesPolydactyl horse toes

ManateeManatee

Basilosaurus

Vestigial Structures

The presence of a vestigial organ doesn’t greatly affect an organism’s ability to survive and reproduce (Tiny legbones on snakes

don’t help, but they don’t really hurt either)

(Evolving them out isn’t really a “priority”)

SnakeSnake HumanHuman