Humans are pretty blessed in the butt department. We might not measure up in volume to say, an elephant – but in terms of body to butt ratio, we’re doing pretty damn well for ourselves.

Buttock volume is, of course, dependent on a person’s individual genotype, and an enthusiastic regime of squatting and lunging can go some way to boosting the posterior. However, according to the Institute of Human Anatomy (IHA) we still, as a species, have the biggest booties of the animal kingdom. Butt why? (Pun very much intended)

Why do humans have such big butts?

Human butts include a gluteal fold and a gluteal cleft (that’s the bit down the middle), as IHA co-founder Jonathan Bennion and lab director Justin Cottle so generously demonstrate in the below video. What makes the tissue between the two so generous on the human form is largely to do with how the muscle is attached to the skeleton.

Using a real human cadaver (the kind you get at body farms) Bennion takes us through a dissection of the buttocks' surface anatomy, beginning at the epidermis and dermis which is effectively the skin. Under here we have the hypodermis, made up of fatty tissue known as adipose, the thickness of which is dependent on fat volume which can be determined by a person's lifestyle or genes.

However, this is not the secret to humankind’s generous butts, oh no. For that, we have the gluteus maximus to thank.

The Gladiator-sounding muscle group plays a huge role in human locomotion, connecting the spine, hip and femur together to mobilize the hip as the gluteus maximus stretch and contract. This is why growing your glutes is helped by movements such as deadlifts, which sees the gluteus maximus stretch and contract to extend the hip before the butt muscle pulls it all back to an upright position.

The gluteus maximus is constantly engaged as we go about our days as bipedal, upright animals. Unlike, as Bennion demonstrates, cats, who run around on all fours and therefore don’t engage the glutes in the same way.

The more a muscle is used, the bigger it gets, and so in evolving to be upright animals we earned ourselves the skeletal position needed to claim the big butt title.

The accolade was wonderfully demonstrated in an (albeit edited to be more bootylicious than the original) meme about Perseus and his considerable cheeks.

And humanity has proved time and time again that it has many uses for a generous gluetus maximus.

So, one curious question about the human derriere tackled, but wait… why do humans have butt hair?

[H/T: Men’s Health]