Species are surrounded by other species (often sharing the same body), and therefore may interfere with one another’s fitness.
Scientists have experimented extensively on the classic lab animal, the fruit fly, mutating its genes in every way they can.
In the full course, Dr. Axe investigates proteins and how they work, the genetic code, gene recruitment, population genetics, natural selection, and much more.
There’s a problem with evolution by “natural selection” that’s indicated in the very words themselves, as biologist Doug Axe points out.
You can watch Axe taking on arguments for “stupid design,” as offered by well known atheists like Neil deGrasse Tyson or lesser lights such as Nathan Lents.