Here’s a link to a fascinating article in National Geographic on twins — mostly identical twins and research on their similarities and differences, even in cases in which they were raised apart.

When Kayla and Kendall were smaller, I really couldn’t tell them apart until Kendall’s hemangiomas grew on the back of her head and on her chest. Now those marks are faded some, but most of the time I can tell them apart by looking at their faces and behavior. (I’m ashamed to say that as their mother, there are still times I get them confused, however.)

Kayla, I think, from awhile back ... I'm guessing this is her because she's in pink and this highchair is generally the one we put her in.

I'm pretty sure this is Kendall. She has less hair, her eyes have a more Kendall-like expression and again, the brown highchair is pretty much hers.

I can’t wait to see if I’ll be able to tell their voices apart someday, when they’re really talking. Many of my family members can’t distinguish between my sister and myself over the phone, and we’re 6 years apart. And we make the same faces.

I also wonder if they’re going to look enough like Ava that people will get them confused for triplets at some point. My sister and I have gotten confused for twins several times in public, and many people in my hometown approach her thinking she’s me.

The wonders of genetics!