The phrase "mammoth genes" refers to the genetic material or DNA of mammoths, which were giant, ancient relatives of elephants. It suggests the idea of using these genes to potentially bring back or recreate mammoths in some way. Full definition
Take a living elephant genome and cut and paste important mammoth genes into it so you get all the mammoth traits you want. (reviverestore.org)
In other words, transferring 45 of the largest - effect mammoth genes into an elephant all at once is unlikely to have a beneficial or useful outcome. (medium.com)
Already, news of mammoth genes cloned in living elephant cells has emerged from two research groups this year. (newscientist.com)