Chemistry
How DNA Replication Errors Lead to Point Mutations
Quick fact
DNA polymerase makes about one error per 100,000 nucleotides copied, but proofreading reduces that to one per 10 million. With the additional mismatch repair system, the final error rate drops to about one per billion—yet those rare errors are the raw material for evolution and can also cause disease.
Why this is interesting
Your body copies billions of DNA letters every time a cell divides, yet it makes almost no mistakes. But when errors do slip through, they can change the code of life forever—what goes wrong?