Metastable epialleles may sound like complex science, but they help explain why identical animals can still look and act differently. For years, scientists asked why two mice with identical DNA could ...

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 ...

For more than a century, scientists have debated whether intelligence is mostly a product of nature or nurture. Identical twins—those born with the same genetic blueprint—have long been the perfect ...

Twins are taking over! These days, around 31 out of every 1,000 babies born in the U.S. are twins, according to the Centers for Disease Control and Prevention (CDC). Back in 1980, only about 19 in ...

Discovered: The world's lightest material; babies understand more than we thought; even in the womb, identical twins aren't completely identical; superweeds are resistant to RoundUp. Germans break the ...