Noah Brier | August 10, 2023

The Metamorphosis Edition

On caterpillars, cocoons, and competition

Noah here. A few months ago, I wrote the caterpillar edition, in which I described my amazement at learning just what happened in metamorphosis:

At some point, probably ten years ago, I first learned about what happens when a caterpillar goes into a cocoon. I proceeded to go around telling everyone I could find how insane the process of metamorphosis was. A small creature builds a little house and proceeds to disintegrate into goop, only to be put back together as a butterfly (or moth, or a handful of other bugs). The process is absolutely mind-boggling. After dissolving itself inside the cocoon, the only things left are called imaginal discs. “Before hatching,” explains Scientific American, “when a caterpillar is still developing inside its egg, it grows an imaginal disc for each of the adult body parts it will need as a mature butterfly or moth—discs for its eyes, for its wings, its legs and so on.”

The kicker in that piece was about insects' glue-like role in ecosystems, relying heavily on this Elizbeth Kolbert quote, “Collectively, insects transfer more energy from plants to animals than any other group. They are the solder that holds food chains together.”

WITI Classifieds:

We are experimenting with running some weekly classifieds in WITI. If you’re interested in running an ad, you can purchase one through this form. If you have any questions, don’t hesitate to drop a line.

Interpreting the internet for the tasteful reader. Join 23,000+ subscribers who rely on Dirt for their cultural alpha. Subscribe for free.

Why is this interesting?

Once again, I found myself reading about metamorphosis. This time in a Quanta piece about a recent piece of apparently monumental research about whether insects maintain their memories when they move to the other side of their goo phase. (The article’s conclusion is probably not.)

But what stood out most in the piece to me was this evolutionary explanation for why metamorphosis exists at all:

Most researchers now believe that metamorphosis evolved to lessen the competition for resources between adults and their offspring: Shunting larvae into a very different form allowed them to eat very different foods than the adults did. “It was a great strategy,” Truman said. Insects that started to undergo complete metamorphosis, like beetles, flies, butterflies, bees, wasps and ants, exploded in number.

A perfectly elegant explanation for a beautiful and insane process. (NRB)

Thanks for reading,

Noah (NRB) & Colin (CJN)

Why is this interesting? is a daily email from Noah Brier & Colin Nagy (and friends!) about interesting things. If you’ve enjoyed this edition, please consider forwarding it to a friend. If you’re reading it for the first time, consider subscribing.

© WITI Industries, LLC.