It’s hard to overstate just how brilliant and huge an idea Charles Darwin’s theory of evolution by natural selection was and continues to be. It absolutely rocked Victorian England, to the extent that stuffy old Victorian England could be rocked past people just barely raising their voices in polite protest. But some folks, particularly highly religious types, weren’t too happy with the idea that nature can run perfectly fine on its own, without the guiding hand of a higher power. Not happy in the least bit.

But contrary to popular belief today, scientists were kicking around the idea of evolution before Darwin—even Charles’ grandpa, Erasmus, alluded to it in verse, like a true OG. Charles’ contribution was specifically the natural selection bit, that organisms vary, and these variations can better suit individuals to their environment, thus boosting their chances of passing down these traits to future generations. (Weirdly, Darwin’s friend, the brilliant naturalist Alfred Russel Wallace, had arrived at the same idea independently at around the same time. The two presented their preliminary findings to the Linnean Society of London, before Darwin blew the lid off the whole thing with On the Origin of Species.)

There was a bit of a problem with all of this natural selection stuff, though: Darwin didn’t know how it, uh, worked. Offspring had a mix of their parents’ features, sure. But how? What was going on at the moment of conception? It was a huge hole in Darwin’s theory of evolution. So in 1868, almost a decade after he published On the Origin of Species, Darwin tried to plug that hole with the theory of “pangenesis,” a wildly wrong idea that goes a little something like this:

Every cell in our bodies sheds tiny particles called gemmules, “which are dispersed throughout the whole system,” Darwin wrote, and “these, when supplied with proper nutriment, multiply by self-division, and are ultimately developed into units like those from which they were originally derived.” Gemmules are, in essence, seeds of cells. “They are collected from all parts of the system to constitute the sexual elements, and their development in the next generation forms a new being.”

Because both parents contribute these cell seeds, offspring end up blending the features of mom and dad. But what about a child exhibiting more features of one parent than the other? This comes about when “the gemmules in the fertilized germ are superabundant in number,” where the gemmules “derived from one parent may have some advantage in number, affinity, or vigor over those derived from the other parent.” In other words, they kinda just put more effort into it...