The mammalian placenta depends on a protein that came fro... | funfact.wiki | funfact.wiki
The mammalian placenta depends on a protein that came from a virus. An ancient retroviral sequence was repurposed to make syncytin, which helps cells fuse at the boundary between mother and fetus. Placental mammals may partly owe their birth system to an old viral infection.
Walking with same-side arm and leg moving together (lateral walk) is actually the most common gait among mammals — dogs, cats, elephants, and deer all walk this way. In Edo-period Japan, people also walked this way, using a style called "nanba."
A camel's hump stores fat, not water — and evolved for the Arctic, not the desert. 3.5 million years ago, ancestors in Arctic Canada grew fat-storing humps to survive winters. When they migrated south, the hump proved equally useful in the desert.
In 1980s Australia, male beetles were found mating with beer bottles. The brown color, size, and bumps on the bottles mimicked female beetles, acting as a "supernormal stimulus." When this threatened the species, Australian breweries redesigned their bottles, removing the bumps.
Zebra stripes defend against blood-sucking insects like tsetse flies. In experiments, flies couldn't land on striped surfaces — they crashed or flew past without slowing down. Even regular horses wearing striped coats repelled flies.