13. Penguins and Evolution in Reverse
Most people see the average Penguin and wonder why we’d ever see a penguin develop wings that it simply cannot use. Yet beforehand, Penguins actually could fly and those wings were used for that exact purpose. However, in one of the most bizarre ways evolution is proven to us through penguins, they became flightless for a key reason. Penguins typically waddle when walking so they often slide around from place to place on their stomach region to move quicker.

This is smooth enough, just like their entire body, to move about without any real issues. This same skin/feathering allows them to glide through the water with ease too. However, their wings once used for flight are now made specifically for them to use as key aides to their movement and speed in the water. Flight capability was no longer evolutionary necessary to Penguins while speed in the water simply was, which is why the change happened.