There’s this is podcast that I’ve been listening to for several years called the Skeptic’s Guide to the Universe. It’s a science podcast, talks mostly about science-y stuff, but it’s also about critical thinking, misinformation, and about skepticism as a practice.

Even the word “skeptic” itself needs to be defined clearly in polite conversation, because the misinformation merchants have made lucrative the disingenuous “do your own research” line of cynicism which is conflated with skepticism. The best definition I’ve heard is skepticism is the marriage of scientific method and consumer protection, This is personified by the approach of James Randy (a reformed magician who turned his career into teaching people about how your own mind fools itself) and Carl Sagan (who turned his immense scientific knowledge and talents into public education and the generation of wonder).

But this isn’t about the podcast. If you like that stuff, listen to it. If you don’t, go back to Joe Rogan. I raise it because there was a recent episode where they talked about the regrowing of limbs, and the shifting scientific understanding of why some animals, like the axolotl and some salamanders, can regrow entire limbs. While other animals, like mice, for example, can grow back single digits if they’re cut off, and humans have very limited ability to do this. Apparently, we can replace a fingertip, and it will usually grow back fine, as long as the nail bed remains intact, take it past that first phalange, though, and no luck. And it’s not just limbs, but also organs. We can rebuild our livers from a small amount of tissue, but not so much with our hearts. There are different limits with all animals.

Turns out there is a lot of recent research about why this is. At least partly to determine if modern medical technology could allow us to grow back severed limbs or organs. There are a few different ideas about how to undertake this as a bio-engineering exercise, and again, I don’t want to talk about that here. However, in the story I learned something new (sorry medical folks out there for whom this is obvious and perhaps for my brutal simplification!). There are specific genes (SP6 and SP8) that encode for growing new or replacement limbs, and humans carry those genes. Our common ancestors with the salamander and the mouse also carry those genes, and they carry on as an important part of embryonic development, but in humans they are shut off at some point . There are other genes that we have that are turned on that are responsible for growing scar tissue.

Not all animals are like humans, in that when we get a serious injury, our body’s first reaction to that serious injury is to grow scar tissue over the injured space, so that the wound can heal itself so that we can cut off infection and so that the body can adapt to its new reality in more effective way. Turns out that growing scar tissue, from all of its benefits, also means or cuts off the ability for your body to grow the limb back in its stead. Sometime back in primate developmental history, the forces of evolution decided that like most mammals, and in most cases, the growing of scar tissue instead of replacement limbs is the survival advantage that was selected for. And that’s the part I want to talk about.
I’m not having a good time right now. There are specific things going on right now where the work I’m doing and the place I’m in is wearing me down. I was recently at a conference talking with other local government leaders around the region, and they were also feeling this wearing down. Some were handling it better than others. I’ve always been in the former; right now I’m in the latter.

The common phrase we use around this kind of burnout, especially when it relates to elected officials, is “you have to grow a thick skin.” Scar tissue.

I’m wondering if scar tissue is really the best way for us to heal when we’re losing pieces of ourselves. Maybe if we get past that idea, turn off the scar tissue meme and on the regrowth one, we can actually restore what we are losing? Why should the ability to thicken your skin – to grow a scar – be necessary? What is the opportunity cost of putting all that energy into scar tissue? Without change, even the scars are word thin, and what are you left with?

I was walking through Uptown today and ran into a young friend who has had a tough path for a few years, with their self-recognition and confidence and place in the world. But in the last year or so, I’ve watched them blossom into a confident and reflective young man. I was spiraling in my own stresses and self-doubt, grumbling down the street with the whole world feeling like a thundercloud out in front of me. I was building scar tissue. And after 5 minutes of talking to them, I was inspired. I didn’t see their scar tissue, I saw their regeneration – still an ongoing project for them, still hard I’m sure (ugh, High School) but they are doing good.

So fuck scar tissue and building a thick skin. They are nothing to be proud of. Let’s do better and strive for regeneration. That way there will be more limbs to do the lifting, more hearts to do the caring, as we continue in the work of stopping the harms in the first place.

Take care of each other out there, folks.