Aspen, David, Aspden discussed on This Week in Science

Automatic TRANSCRIPT

Sometimes it's kind of fun anyway, they're very old longtime ago and they include some of the oldest vertebrates this group of fishes with a mineralized skeleton that has ever been discovered, but they're really old in its fossilized tissue. And so the question is what exactly is. That fossilized tissue made of is it made of bone. And so there are skeletons in living vertebrates that are that come from four different times kinds of tissue. The have bone, which we know of is the hard stuff inside our bodies. There's cartilage, which is like stuff in your ears and your nose, the soft stuff, and den teen and enamel which are teeth are constructed from and these tissues. All of them are unique because they become mineralized as they develop. And that's what gives strength and rigidity too there structures. So researchers wanted to know exactly the the question of primitive bone tissue. What? What really, how did where did it come from the bay say in their the abstract of their paper, the crux of the controversy. Eighty in the question of the of bone is the nature of the UN mineralized spaces that are found all through the matrix in these early vertebrates skeleton fossils and they say it's a bone like tissue. They call Aspden is what they call this tissue. And so the spaces that are inside the mineralized bits, they have been hypothesized to have housed living cells which is similar to our bone where living cells give rise to the mineralized structure of the bone, or whether they had cell processes or particular fibers inside of them. And so they used synchrotron x Ray tomography to get at this true nature of Aspen, and they were able to determine that once and for all these voids that were there in the structure of this early bone like substance were not from living cells. And so this Aspen that they call it is a cellular dermal bone, and they reject the hypothesis that it is a type of Dentin cellular bone or even a transitional tissue, let something like a cartilage. And so what they think based on their study is that the full range of skeletal tissue types were around before vertebrates arose. And so the tissue types were all there. They just weren't being used to create a skeleton. In the way that the vertebrates are known to. And so it was a rapid evolution that occurred that led to the the use of all those tissue types to create the ver the vertebral column and skeleton. Sometimes you gotta look at the little things and I like the. The the scientific method here. I mean, they were cutting away hypotheses. You know, it's like we're going to look at the evidence and we will get rid of the hypotheses that are evidence. Doesn't line up with our evidence goes this way, no cells. This was not a living cell that there were no living cells that then created this structure around them and supported it. No, it was something different. So we'll get rid of that hype asus. So that's the scientific method in action. Very visibly. That's why I kinda liked to this study the most, but I know I, yeah, I'm bones the mystery of the origin over skeletons being solved. The study was published in nature, ecology and evolution. If you're interested in following up on it, it makes me wanna go back through. It doesn't actually, but it makes me really excited for going back through college or the people who are going to go through vertebrate biology, evolutionary morphology, stuff like that. They're gonna have so much more answers than any of us had. It's I. I mean, I even remember when I went through, they were like, yeah, and then there were turtles, and we were really sure there was this weird. You know, there's no middle ground. And then while I was taking that class, they found a fossil with a plaster on. Right. And so this is exactly like that David saying, okay, and then there were bony fishes, and we're not exactly sure how, and now we're gonna know we're going to have a real answer to be able to provide in the history of the evolution of life. Yeah, so neat is I think it's very neat. All right. Tell me about drugs. Justin drug is up. Okay. Turns out that the Yusen prescription opioids in the United States which has been an epidemic. It's been called the health crisis..

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