Comic books play with the specious possibility of science. To drive the point to some half-sense, some actual science can be used to explain some of them, so Standord University's biologist Sebastian Alvarado decided to explain the genetic transformation that made Captain America and The Hulk possible.

A lot of gene manipulation is involved.

Science knows about the genes that increase muscle mass.

We also have a lot of tools to manipulate those genes.

Theoretically, Captain America is scientifically plausible.

Then there's The Hulk. Gamma radiation actually alters your DNA.

The mystery lies in the reassembly of chromosomal data.

Genetic modification is in the Hulk's DNA. Which lets him transform to and fro from Hulk and Bruce Banner.

Watch it: