Although there are significant advantages to sexual reproduction, some species — like this tiny roundworm — are just fine going without.
In fact, these worms haven’t had sex since they originated roughly 18 million years and they’ve survived perfectly fine on their own while maintaining sufficient genetic diversity.
Sexual reproduction is an effective method for rearranging genes and lessening the chances of unwanted mutations, which is why asexual species so commonly go extinct after short periods of time. However, a new study published in Current Biology turns the tables on sexual reproduction with the self-cloning worm, Diploscapter pachys.
“Somehow, the worm fused its ancestors’ six pairs of chromosomes into one pair of huge chromosomes. It did away with a major step of meiosis — the part of the reproductive process where chromosomes reshuffle before splitting into two cells,” reports Rae Ellen Bitchell for NPR.
This trade-off of sex for precise cloning has definite advantages. Plants and animals spend much of their time and resources on sex, including competing for mates and the act of reproducing itself. But for asexual species, reproduction is as simple as making copies of themselves.
This roundworm’s impressive form of cloning involves copying its genes with just enough genetic mutation for sustainability while minimizing the chances for defects.
“This phenomenon is a significant one in understanding evolutionary genetics because it runs counter to the widely accepted view that sexual reproduction is required to eliminate deleterious mutations and for adaptation to a changing environment,” David Fitch, one of the study’s co-authors said in a statement.
While research shows that this abstinent worm evolved from parents who practiced sexual reproduction, its own methods seem to be serving the population just fine.