Imagine that you’re hiking through dense forests in southwestern China when you hear a small tree branch crack ahead of you. You freeze. Scanning the undergrowth, you spot a large, dark presence, like a shadow, also frozen. Your eyes meet the shadow’s–silver-grey orbs amid shiny green leaves. Then, in an instant, the shadow vanishes, like the darkness suddenly remembered the light. With a pounding heart you try to process what you just saw.
Back at a village you learn that you met face-to-face with a black panther. But you pull out your phone to look up black panthers only to learn that they don’t exist.
These kinds of encounters explain why many indigenous peoples thought that black panthers were a distinct species of large cats. They are striking creatures without obvious stripes, spots, or manes. However, black panthers are not mystery beasts; they are genetic anomalies, like attached ear lobes or the ability to roll your tongue.
Thanks to modern genetics, we now know that what we call a panther or black panther is actually a melanistic variation–an increase of the pigment melanin expressed in the cats’ coats–of two other large cats: the leopard and the jaguar. In leopards, melanism comes from a dominant allele (like having an unattached earlobe); in jaguars, it comes from a recessive allele (like being able to fold your tongue). These alleles, or alternative forms of the same gene, are the microscopic source of the black panther.
Black panthers are any melanistic variant of the species within the genus Panthera. In fact, the term “panther” can refer to a leopard, jaguar, or cougar based on where you are in the world. There is no true panther like there is a leopard or lion.
Black panthers aren’t even wholly black. Look closer at a panther’s coat and you’ll find that the characteristic spots of the leopard and jaguar are still there, hiding under a cloak of excess melanin in what is called “ghost striping.”
Though black panthers may not be anything more than leopards and jaguars with a fairly common mutation, the mythos of the panther remains, like the hero from the fabled source of vibranium: Wakanda. And to be fair to the superhero, melanistic leopards are found in and around Kenya, one place where Wakanda is rumored to be.
Kyle Hill is the Science Editor of Nerdist Industries. Follow him on Twitter @Sci_Phile.