Happy New Year. I'm Flora Lichten, and you're listening to Science Friday. Okay, New Year's resolutions. I get it. They're a cliche. I know they rarely stick. But I like them. I like thinking of the new year as a fresh start. I like believing that we, I, have the capacity to change

and to evolve. New year, new me. Yes, it sounds like an inspirational greeting card line,

but you know what? It's also true biologically. On a cellular level, we are remaking ourselves

every moment of every day.

Just think by 2027, you will have lost and replaced a mass of cells equal to your entire body weight.

And if you really want to talk about starting anew, there are animals that can regrow their own head from a piece of their tail.

That is growth mindset.

I find these ideas interesting and helpful this time of year when I'm thinking about how I want to grow,

which is why I wanted to talk to Dr. Alejandro Sanchez Alvarado, president of the Stowers

Institute for Medical Research, to hear about his

pioneering research into regeneration and the science of becoming and rebecoming.

Alejandro, are you on board with my premise? I mean, do you think about your work metaphorically?

It's inescapable. I think that anybody that works on an area where you can see

transformations unfold right before your eyes cannot avoid thinking about metaphors. You know,

in fact, most of developmental biology is populated by metaphors.

We describe in these processes with metaphors, and we're so aware of that metaphorical thinking

that we constantly tell ourselves that the problem with metaphors is that they require constant

vigilance, because you don't want the metaphor to actually become the thing that

you're studying. So yes, I mean, we do think a lot about that. Oh, that's interesting that the metaphor

can actually, you don't want it to drive the cart, you know, to lead the horse or whatever. Yeah,

that is correct. Yes. Let's start with this worm that I alluded to in the introduction. We're

talking about a plenarian.

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