It’s common for people to claim that twins skip a generation, especially if there are already twins in the family. For years, the belief that twins skip a generation has been floating around. While some instances prove this is the case, some also prove that twins do not skip a generation.
Sometimes twins skip a generation and sometimes they don’t. This had led some to say that twins are not genetic and some still believe that they are. The ways genes are passed down could explain why people have seen twins skip a generation in their own families. It also explains why a family with twins, won’t always see another set.
The truth lies somewhere in between genetics and happenstance. Twins don’t always run in families and sometimes never occur again during a whole lineage. Conversely, in some families twins skip a generation every time. What makes the difference in whether or not twins skip a generation? Experts don’t really know exactly, but what they do know is fascinating.
Why do people think twins skip a generation?
Like most rumors, people believe it because they have seen it happen. And researchers believe the reason people have seen twins skip a generation is because of a gene the pregnant woman has. Even though scientists speculate that the gene for hyperovulation may be responsible for fraternal twins, there is no real evidence that this gene is solely responsible for producing twins. This gene only makes a woman produce more eggs, which allows for a higher chance of twins.
The same is not true for identical twins though. Identical twins occur when one egg splits into two separate eggs, resulting in twins with the exact same DNA. Since identical twins come from one egg, the hyperovulation gene has nothing to do with their occurrence. This means that hypothetically it would be more accurate to say that fraternal twins skip a generation, since that can sort of be proven. But – only sort of.
Do twins skip a generation?
The answer is they could but they don’t always have to. It actually comes down to genetics. Both men and women can carry the gene for hyperovulation down from their parents. Since men don’t ovulate, they can only be carriers. Women however can actually have hyperovulation if it’s passed down to them, but not always. If the gene is recessive, the woman may not have hyperovulation, and therefore be less likely to have fraternal twins. If the gene is dominant and passed to a woman they would likely have hyperovulation and be more likely to have fraternal twins.
If the man carries the gene, he could pass it on to his daughter which could theoretically make twins skip a generation. Since this is largely based on chance and less about genetics, whether or not the man carries the gene for hyperovulation may or may not mean that his grandchildren will be twins. It’s also possible for fraternal twins to occur without the hyperovulation gene, so even the gene isn’t a sure fire way to predict twins in a family.
So the truth is – twins can skip a generation but they don’t always.
