The changes in Scott’s DNA were subtle, yes, but significant enough that after he got back to earth and his body readjusted, NASA said he and his brother were “back to being nearly identical.” Weird.

Hair Color

The Kelly brothers don’t have any hair, so we’ll leave them for now. My mother has salt-and-pepper hair, while my aunt is completely white-headed. Again, lifestyle differences can explain this different hair color, just as hair dye explained when my mom was salt-and-pepper and my aunt dashed around town with jet black hair.

Wrap Up

Of course, identical twins can color their hair differently from dyes and lifestyle differences. But if one twin was born with a hair color different from their sibling, they are not identical twins.

Later in life, environmental factors may affect how twin genes continue to express themselves, but you’re not going to have one twin with thick, curly, coarse black hair while her identical sister has wispy, gossamer white-blonde locks. Those would be fraternal twins.

More Interesting Topics for You:

• How to Know If You Have A Big Forehead

• Signs of Hair Miniaturization – And How to Reverse Them Non-Surgically