Goto told Iritani his vision: find mammoth sperm with genes still intact and use it to fertilize a living elephant egg. If the resulting hybrid was a female, he could then fertilize its eggs with more mammoth sperm, breeding a line that would become more and more mammoth. Iritani didn’t want to be limited to the hybrid approach. If mammoth sperm successfully fertilized an elephant egg and the resulting embryo took to a surrogate mother, a half-mammoth/half-elephant wouldn’t be born for 600 days. (Elephants have the longest gestation of any mammal.) A hybrid female should reach reproductive age in 10 to 15 years. It could take 35 years, from start to finish. “I’m 15 years older than Goto,” Iritani says. “I can’t wait 30 years to see a mammoth.”
Mammoths (fossil shown here) made up only one branch of a great tree of elephant evolution.
The first elephant-like mammals such as Moetherium did not yet have the great tusks and trunks that we associate with elephants. advertisement | article continues below
A huge diversity arose, including species with tusks shaped like shovels. The African and Asian elephants alive today represent a tiny remnant of that diversity.
|
