That brings the total number of species to five: these two whales, plus killer whales, short-finned pilot whales and us. They knew that the toothed killer whales also go through menopause, based on four decades of research. Other toothed whales, such as sperm whales, remained fertile. This new work suggests that menopause evolved independently in toothed whales three times: once in killer whales, once in short-finned pilot whales and once in the common ancestor of narwhals and belugas. If we understand the circumstances that led to whale menopause, perhaps we can better understand it in ourselves.

Source: Washington Post August 27, 2018 16:15 UTC