Don’t even bother trying to compare your body plan with a sponge. You could try, but the mere fact that you were trying would reveal something more psychiatric than anatomical.

My building was constructed in 1896, and the utilities reflect an odd design that has been jerry-rigged further with each renovation. If you want to understand the wiring and plumbing in my building, you have to understand its history, how it was renovated for each new generation of scientists. My head has a long history also, and that history explains complicated nerves like the trigeminal and the facial.

We would never have scales, feathers, or breasts if we didn’t have teeth in the first place.

Every limbed animal has the Sonic hedgehog gene.

Each galaxy, star, or person is the temporary owner of particles that have passed through the births and deaths of entities across vast reaches of time and space. The particles that make us have traveled billions of years across the universe; long after we and our planet are gone, they will be a part of other worlds.

We would never have scales, feathers, or breasts if we didn't have teeth in the first place.

With respect to the ZPA, what kind of digit develops depends on how close the digit is to the source of Sonic hedgehog.

We were staring at the origin of a piece of our own bodies inside this 375-million-year-old fish. We had a fish with a wrist.

The world is filled with puzzles, all kinds of interesting questions and it's our challenge to figure them out. It's not just like this static file cabinet of things that human beings know. It's ever expanding.

It took a long time for us to figure out really the extent of what we had.