A new study suggests that lifespan might be 50% heritable — although for now, it's hard to know if the finding applies across diverse populations.

Identical, or monozygotic, twins develop from the same fertilized egg that splits into two. These twins are the same sex and share the same genes. Sometimes called paternal twins, identical twins ...

Early sea urchin embryos can be split into two, and each half can develop into a complete individual. In other words, they can produce identical (monozygotic) twins—a phenomenon known as regulative ...

An international team of researchers led by King’s College London have identified genetic factors that may make some individuals more or less sensitive to the environments they experience. Published ...

Sesquizygotic multiple pregnancy is an exceptional intermediate between monozygotic and dizygotic twinning. We report a monochorionic twin pregnancy with fetal sex discordance. Genotyping of amniotic ...