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Celeste Berg

Have you ever wondered why you look like your parents? Why you have your father's nose, or your mother's eyes? I look so much like my Mom it is scary.

I have a twin sister and she looks more like my Dad. My parents always treated us exactly the same, yet we are so different! Not only do our physical features differ but our personalities and temperaments differ too. She was always the angel, doing kind things for others (the 'good' twin), and I was more critical (the 'bad' twin). From early on, I wondered why we were alike and yet not alike. Now I am a geneticist and I study how genes control our development and make us what we are.