Silverback gorillas are famous for their impressive, bulging physiques — and their rather modest genitalia. Now, scientists have uncovered a potential genetic link between these apes' small members and infertility problems in male humans.
Coming in at just 1.1 inches (3 centimeters) long, on average, the penis of the adult male gorilla (Gorilla) is the smallest phallus of all apes. The gorilla's genital size comes with other deficits in its reproductive capacity, such as low sperm count compared to other primates, and sperm with poor motility and a diminished ability to bind to eggs.
