These babies share somewhere between 50% of the same DNA (like dizygotic twins) and 100% (like monozygotic twins). Scientists have discovered that a phenomenon called polar body twinning is ...

These twin share the same genetic material ... Some researchers speculate about a third category: polar body twins or half-identical twins. This rare phenomenon might occur when an egg splits ...

These twins are the same sex and share the same genes ... Half-identical or polar body twins are born together. However, the mother’s egg splits in two and each half is fertilized by sperm ...

Meanwhile, someone with the same face, body, and DNA was back on Earth: his identical twin, Mark Kelly. Scott and Mark are the only twin NASA astronauts in history. Separated by 250 miles of space ...