🎬 CUTTING ROOM FLOOR: A Fish's Butthole DNA Helped Shape Our Fingers! (Podcast Exclusive)

Join Jonesy & Amanda for an EXCLUSIVE (unaired) episode!

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Episode Transcript

Speaker 1 (00:10):
My Heart podcasts here, more Gold one on one point
seven podcasts, playlists, and listen live on the free iHeart app. Everybody,
it's time for Jonesy and Amanda's cutting floors. On the

(00:32):
cutting room floor today, I see you wearing the science
lab coat. That can mean only one thing. What's that
I have done my washing? It's science time, you know.
When I chose, I felt that it was time to
leave beyond two thousand. When I had a day off
in Paris, I've been working on the show for about
six years, traveling a lot, and I looked across the

(00:53):
road and thought, oh, that looks like I had a
day off. But that looks like a nice dress shop.
I'll go in there. It was medical supplies. I was
looking at a lab coat. Maybe it's time for Middle East.
I can't recall you wearing a lab coat many times.
Lab coats, hairnets, ye, cotton booties, you know, all that
kind of stuff. It looked like I was on the
election campaign trail constantly, your hard hats, welding all that

(01:16):
kind of stuff you are welding heard hats, but you
know that sort of stuff that you see politicians do.
I didn't have to kiss many babies, and you predated
high vis as well, that's right, there was no high vis.
I was just normal vis. You were just visible. This
is a science. I but I think this story will
appeal to you, Brendan, and it is quite fascinating. About

(01:37):
three hundred and eighty million years ago, this is literally,
this isn't just my Beyond two thousand years, fish swimming
in the Devonian Seas carried a genetic program that would
later shape human hands. Well, a new study published in Nature,
so you know it's reputable. This isn't some sort of
crazy woo woo magazine. It reveals that the DNA switches
responsible for forming fingers and toes did not evolve from Finns.

(02:00):
It would always thought that Finns evolved into fingers and toes.
But in fact, these switches and these DNA changes are
you ready, were recycled from the kloaka, the bum a
fish bum the multi purpose excretory and reproductive opening still
found in many animals. Chickens have a cloaka. I think

(02:21):
reptiles do they have a cloaker. It all comes out
of one hole. Everything happens through one hole. So researchers
from the University of Geneva and other collaborators have traced
the connection using mice and zebra fish embryos. Both species
share a certain gene, the master architects of building bodies.

(02:42):
In mice, these genes light up in budding digits, guiding
their growth into digits. In zebra fish, the same genes
illuminate the cloaka oh both. When scientists then change that
DNA mouse digits failed to form zebrafish, the cloaka collapsed,

(03:04):
but the fins remained, so they said, the fins and
the fingers aren't related. The cloaca and the fingers are related.
Are you keeping up? I am? This genetic recycling is
known as evolutionary co option. It shows that nature builds
new structures not by inventing fresh systems, but by retooling
old ones, for example, the same way that an old

(03:25):
machine can be made from using other bits. So the
cloacal regulatory landscape was reassigned to sculpt digits as fish
ventured onto land. That's interesting. So it wasn't the fins
that became arms and fingers, it was your cloaka. So
the work reframes one of the great evolutionary transitions. To

(03:46):
move from fins to limbs. It wasn't a clean break,
It was a clever rewiring of ancient instructions. So every
finger that we flex today, do this with your handbread
and flex your fingers. Every finger that reflex carries the
legacy of a cloacal blueprint. So you're saying that man

(04:07):
and woman's hands came out of a fish's bum. Yes,
I'm glad you've paid attention and you've given us that
scientific summary. I like it when you put on the
lab coat. Thank you the cotton. Okay, kids, that's it
for today. Come back tomorrow from more of Chelsea and
a man that's cutting room for the cotton fall.