Animals aren’t just adapting in urban environments, though. They’re physiologically changing to survive living with humans. For example, in some places, there has been a rise in the number of elephants born without tusks. That’s because poachers are more likely to kill those with tusks – while tuskless ones survive and pass on their genes, including the “tusklessness” trait. In other words, being tuskless has become an evolutionary advantage in places where poachers are a major threat.
