How do identical twins become genetically distinct?
Quick Answer
Identical twins start with the same DNA, but they can become different because of mutations, epigenetic changes, and environmental influences. Their bodies and brains are not exact copies over time.
The Full Story
Identical twins usually begin as one fertilized egg that splits early in development, so they start with nearly the same genome. As cells divide, small DNA mutations can occur in one twin but not the other. Epigenetic changes, which affect how genes are turned on and off without changing the DNA sequence itself, also accumulate over time. Differences in diet, infections, stress, and other exposures can make identical twins increasingly distinct as they age.
Key Facts
YouTube Angle
Suggested video title for this topic:
"Same DNA, different people: how identical twins diverge."