Sperm self-sabotage to make sure mothers have a bigger influence on DNA

Here’s a fun biological fact: men pass on less DNA to their children than women do. The reason for this has been a long-standing mystery, though a study published today leads us closer to understanding.

When humans reproduce, women are the only ones who pass on a type of DNA called mitochondrial DNA. Unlike most of our genetic material, this kind of DNA comes from tiny cellular subunits, called mitochondria, located inside the cell's cytoplasm, but outside the nucleus. That DNA is crucial because mitochondria provide energy to the rest of the cell. Both men and women have this kind of DNA, but like I said — women are the ones who pass it on.

Men pass on less DNA to their children than women do

Now, a roundworm study published in S...