大象的嗅觉动物界最灵敏

 

Given the size of their trunks, and how important it is to their survival, it is probably unsurprising that an elephant's nose is not only the longest in the animal kingdom, but also the most effective.

 

In comparison, humans and other primates³ have a poor sense of smell.

 

"The functions of these genes are not well known, but they are likely important for the living environment of African elephants," said author Dr Yoshihito Niimura of the University of Tokyo.

 

"Apparently⁴, an elephant's nose is not only long but also superior.

 

The sense of smell is critical to all mammals, and they use it for sniffing⁵ out food, avoiding predators⁶, finding mates and locating their offspring.

 

In a study published in Genome Research, scientists examined the 13 mammal species and found that African Elephants have twice the number of smell genes as dogs and five times more than humans.

 

They have around 2,000 genes alone that are dedicated to scent⁷. Humans in comparison have just under 400 and other primates like chimpanzees, even less.

 

The study found that 20,000 genes are responsible for the sense of smell in mammals, of which around half are functional⁸, but the collections differ for each species.

 

Horses have around 1,000 smell genes, rabbits around 750 and rats about 1,200.

 

"The large repertoire of elephant (smell) genes might be attributed to elephants' heavy reliance on scent in various contexts, including foraging（觅食）, social communication, and reproduction," added Dr Niimura

分享到：