Life began in the water. Microbes swarmed around in primordial ooze, banded together to form multicellular organisms, and eventually grew complex enough to leave their watery homes and become the terrestrial animals that exist today. Some of those land-dwelling creatures became mammals, and in a surprising twist, three separate lineages of ancient mammals then returned … Continue reading Marine mammals and the legacy of gene loss: evolutionary biology informs policy
External genitalia are an important adaptation to life on the land, where eggs may dry out and there is no water for sperm to swim through. Reptiles, birds, and mammals have extremely diverse external genitalia, but they share a common evolutionary and developmental origin. Mara Laslo explains how comparative developmental studies are shedding insight on the development of these remarkable organs.