Although there are some rare exceptions, identical twins are almost always the same sex. Because identical twins occur when a single fertilized egg splits and forms two embryos, each embryo has the ...

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 ...

Identical Twins Are Genetically Different, Research Suggests SAN FRANCISCO – Identical twins may not be so identical after all. Even though identical twins supposedly share all of their DNA, they ...

Photographer Peter Zelewski has spent the last couple of years exploring the special world of identical twins, questioning not only the incredible bond between them, but also what makes them different ...

When we think of identical twins, we often imagine mirror images — same face, same smile and perhaps even the same talents. But what surprises many is that these genetic carbon copies can have ...

Lori and George Schappell, the world’s oldest conjoined twins, passed away on Sunday, April 7, at age 62. The twins made history in several ways, including becoming the first conjoined twins to ...

The Science of Siblings is a new series exploring the ways our siblings can influence us, from our money and our mental health all the way down to our very molecules. We'll be sharing these stories ...

From Romulus and Remus—the myth of the twin brothers who founded the city of Rome—to the synchronized speech of Australia's "Twinnies" Paula and Brigette Powers, identical siblings have long inspired ...

In 2004, Michigan police found that DNA recovered from a crime scene matched that of Jerome Cooper, a notorious criminal. But what seemed like an open-and-shut case got complicated when the cops found ...