Elephants Evolved Best Noses on Earth
African elephants no doubt have one of the most impressive noses in the animal kingdom, and new research reveals that their superior shnozzes also contain 10,000 genes for smell - the most ever found.
Though elephants may be the most discerning mammalian sniffers - they have more than twice the number of olfactory genes in domestic dogs and five times more than in humans - scientists say that doesn't mean there is necessarily a connection between having more genes and being a better smeller.
"We don't really know how the number of olfactory receptor genes relates to olfactory ability," study author Yoshihito Niimura, a researcher at The University of Tokyo's department of applied biological chemistry, told The Washington Post.
"For example, dogs are known for their keen sense of smell - but we actually already knew that their number of genes was much smaller than mice, who we don't see with that same ability."
But while dogs may be good at smelling certain smells, elephants have a broader range and are able to distinguish between very similar odor molecules - ones that humans and other primates find impossible to separate.
While this fact may be impressive, why do elephants even have so many genes for smell?
"We don't know the real reason," Niimura told National Geographic.
One likely explanation, he says, is that good sense of smell is needed to compensate for African elephants' poor eyesight and help them navigate around their environment. The finding really isn't surprising, Niimura added, given that they touch their trunks to anything and everything.
"Imagine the situation [in which] we have a nose on our palm!"
The study, published in the journal Genome Research, discerned smell-related genes for 13 mammal species, including horses, rabbits, guinea pigs, cows, rodents and chimpanzees.
They found the African elephant has the largest number of olfactory receptor genes ever characterized, numbering at a whopping 10,000.
Upon further analysis, researchers also revealed that over the course of evolution, one ancient gene dedicated to smell has created as many as 84 additional genes that the animals likely use to detect odors specific to their environment.
For instance, elephants in the savannah can pick up on a human's scent from a little over half a mile away, or smell a nice banana from 160 feet away.
In addition, they can use their noses to keep tabs on their family members by smelling urine-soaked soil.
"Want to know what is going through the mind of an elephant? I have always said: Watch the tip of its trunk," Niimura said.