Mirror Images and Perfect Strangers
Sometimes children end up looking exactly like Mom or Dad -- or a brother or sister -- and sometimes they don't resemble anyone in the family. What gives? Kids share 50 percent of their DNA with each of their parents and siblings, so there's plenty of room for variation. If your little one takes after you, he may have inherited a lot of your dominant genes along with recessive ones from you and your partner, Dr. Starr says. If siblings end up looking alike, the mix of genes they inherited was similar. Each of your kids may get instructions for different features: Your firstborn can have your lips, while your youngest gets Dad's.
Keep in mind that development is a dynamic process, Dr. Scheiner says. "As kids get older, genes naturally turn on due to hormones as well as environmental exposures," he notes. In fact, your child's bone structure won't be set until he's in his 20s because so many genes are involved, including those for growth, bone development, and even fat deposits. The moon-faced infant who starts out as a doppelg?nger of his dad could have all your angles as an adult. Until then, you'll just have to sit back and enjoy the slow reveal.