Ontogeny recapitulates phylogeny

(I didn't understand those words either.)

One of the coolest ideas I learned in undergrad is wrapped in the most pretentious clothing imaginable:

“Ontogeny recapitulates phylogeny.”

It was first discovered by a German zoologist (Ernst Haeckel) saw that the embryos of different species looked similar as they developed.

The classic example is that human fetuses have structures that look like gills before they fade away in the later stages of pregnancy.

This mirrors the evolution of the species over time to gain, then lose, gills: the development of an individual baby through gestation mirrors the development of the species through evolutionary time.

So, to break it down:

• “Ontogeny” – the development of an individual as it grows in its mother’s womb

• “Recapitulates” – follows the same steps as

• “Phylogeny” – the development of the species as it evolved over millennia

The theory could be restated as “the development of the individual mirrors the development of the collective.”

Apparently Haeckel fudged his results a bit, which made people Very Mad, but it's still widely graded out as "kinda true, mostly just interesting."

I think it's too pronounced to be completely meaningless.

But in any case: it's a cool concept. Nice one to have in your back pocket.