Whether it's having the "eye of the tiger" or being lionhearted, references to lions and tigers evoke power and determination. That's not surprising given these animals are both large, powerful felines. But they are distinct species. So what do these iconic cats have in common, and how are they different? To answer this question, let's consider the two species' appearances, evolutionary histories and how they live their lives as kings of their ecosystems. Appearance and anatomy The most obvious difference between modern lions ( Panthera leo ) and tigers ( Panthera tigris ) is their distinct physical appearances, particularly their coats. "Just looking at them, you can clearly tell that tigers have stripes and lions don't," Dell Guglielmo , a zookeeper who cares for lions and tigers at Smithsonian's National Zoo, told Live Science. "The lion males have the large huge mane, and the females do not." In contrast, male and female tigers look the same.…