1 Adam: Hmm, no. I can see myself and you in the mirror, Jamie.
2 Adam: We’re not vampires.
3 Jamie: You sound so disappointed.
4 Adam: I can also see how much hair I’ve lost over the years.

For the earliest Mythbusters strips, I used an orange marker to colour some hair onto Adam's head. The very first strip doesn't show it so well, but you can see it reasonably well in this one and this one.

Since then, the orange ink has faded dramatically, and I've never touched it up, so Adam has gradually been losing hair over the run of the comic.