1,165
edits
Difference between revisions of "19: Bret Weinstein - The Prediction and the DISC"
Jump to navigation
Jump to search
19: Bret Weinstein - The Prediction and the DISC (view source)
Revision as of 19:51, 20 February 2020
, 19:51, 20 February 2020→Transcript
| Line 502: | Line 502: | ||
'''Eric:''' Okay. | '''Eric:''' Okay. | ||
'''Bret:''' Evolutionary biology has long been biased in the direction of abstraction. Rather than thinking about mechanism, that is to say we deal in the phenomenology of things. We talk about gross patterns that we see in nature rather than talking about the fine detail of what drives them. That has been changing in recent decades, but it has a long history, and it comes from a very mundane place. That mundane place is that we just haven't had the tools to look, for example, inside of cells and we haven't been able to read genomes. You know, we could have been able to read a gene here and there at great expense, but the ability to peer into genomes is pretty new. The ability to peer into these molecular pathways is pretty new. So anyway, there's a historical bias in evolutionary biology against mechanism and in the direction of phenomenology. I have never been particularly fond of that bias. I have always been interested in mechanism. I'm interested in the phenomenology too, but I've always kept my foot in the door with respect to mechanism. And as an undergraduate, I took lots of mechanism classes. I took a development class at the time, developmental biology was in my opinion, a bit stuck. It is now unstuck in a very dramatic way. But anyway, I took a developmental biology class. I took some or immunobiology. And anyway, I was armed with these things in an environment in evolutionary biology where most people were not, most people were in the phenomenology. And one day I happened to be in a seminar. Dick Alexander was running a seminar for graduate students, and a student was there who was very out of place. He was studying cancer, and he, on a lark, decided to take an evolution seminar that looked good to him in the catalog, and it wasn't right for him. And he gave a talk at some point, and his talk was on his work with cancer and frankly, because all the other people in the room were evolutionarily oriented, nobody was really tracking what he was saying. But what he said struck me like a bolt of lightning. He said that in the realm of cancer research, people were looking at telomeres, which are these repetitive sequences at the ends of chromosomes. And they were toying with the possibility that the fact that these telomeres shorten every time a cell divides, that that is providing a resistance to tumor formation. Very straightforward—counter counts down and that would | '''Bret:''' Evolutionary biology has long been biased in the direction of abstraction. Rather than thinking about mechanism, that is to say we deal in the phenomenology of things. We talk about gross patterns that we see in nature rather than talking about the fine detail of what drives them. That has been changing in recent decades, but it has a long history, and it comes from a very mundane place. That mundane place is that we just haven't had the tools to look, for example, inside of cells and we haven't been able to read genomes. You know, we could have been able to read a gene here and there at great expense, but the ability to peer into genomes is pretty new. The ability to peer into these molecular pathways is pretty new. So anyway, there's a historical bias in evolutionary biology against mechanism and in the direction of phenomenology. I have never been particularly fond of that bias. I have always been interested in mechanism. I'm interested in the phenomenology too, but I've always kept my foot in the door with respect to mechanism. And as an undergraduate, I took lots of mechanism classes. I took a development class at the time, developmental biology was in my opinion, a bit stuck. It is now unstuck in a very dramatic way. But anyway, I took a developmental biology class. I took some or immunobiology. And anyway, I was armed with these things in an environment in evolutionary biology where most people were not, most people were in the phenomenology. And one day I happened to be in a seminar. Dick Alexander was running a seminar for graduate students, and a student was there who was very out of place. He was studying cancer, and he, on a lark, decided to take an evolution seminar that looked good to him in the catalog, and it wasn't right for him. And he gave a talk at some point, and his talk was on his work with cancer and frankly, because all the other people in the room were evolutionarily oriented, nobody was really tracking what he was saying. But what he said struck me like a bolt of lightning. He said that in the realm of cancer research, people were looking at telomeres, which are these repetitive sequences at the ends of chromosomes. And they were toying with the possibility that the fact that these telomeres shorten every time a cell divides, that that is providing a resistance to tumor formation. Very straightforward—counter counts down, and that would prevent— | ||
'''Eric:''' So just for the audience that maybe needs a tiny refresher, we're taught in general that DNA is a string of letters called nucleotides, A, C, T and G, and that, in general, three of those that are adjacent to each other form words called codons. And for every word there is an amino acid or an instruction to stop coding for amino acids. So this is the instruction tape that tells us how to string together amino acids into proteins to make machines, molecular machines. This is some weird different thing, where the region of DNA could be interpreted as coding for a protein, but in fact might be instead just counting how many nucleotides are at the end. So it comes across as a counter. | '''Eric:''' So just for the audience that maybe needs a tiny refresher, we're taught in general that DNA is a string of letters called nucleotides, A, C, T and G, and that, in general, three of those that are adjacent to each other form words called codons. And for every word there is an amino acid or an instruction to stop coding for amino acids. So this is the instruction tape that tells us how to string together amino acids into proteins to make machines, molecular machines. This is some weird different thing, where the region of DNA could be interpreted as coding for a protein, but in fact might be instead just counting how many nucleotides are at the end. So it comes across as a counter. | ||
| Line 512: | Line 512: | ||
'''Eric:''' So this was the theory of [https://en.wikipedia.org/wiki/Leonard_Hayflick Leonard Hayflick]? | '''Eric:''' So this was the theory of [https://en.wikipedia.org/wiki/Leonard_Hayflick Leonard Hayflick]? | ||
'''Bret:''' Yup. It was the discovery of Leonard Hayflick, who basically overturned the prior wisdom about cells, which was that they would grow indefinitely as long as you kept feeding them and making an environment that was conducive to division. So I don't exactly know why that result had been misunderstood at first. Maybe somebody had a cancerous cell line and so they got the wrong idea and it just spread, but Hayflick checked it and it turned out to be false. It turned out there was a number of cell divisions that healthy cells would go through, and then they'd stop. The mechanism was not obvious to Hayflick, but later it became clearer and clearer that the mechanism was these sequences at the ends of chromosomes which shorten each time the cell divides. And the implication was that, potentially, this was a cause of what we call “senescence”. What in common parlance would often be called “aging”, the tendency to grow feeble and inefficient with age. If your cells are each in a cell line and that line has a fixed number of times that it can replace itself before it has to stop, then some point your repair program starts to fail. And that repair program, failing across the body, looks like what you would expect aging—aging follows the pattern you would expect if cell lines one by one stopped being able to replace themselves. So— | '''Bret:''' Yup. It was the discovery of Leonard Hayflick, who basically overturned the prior wisdom about cells, which was that they would grow indefinitely as long as you kept feeding them and making an environment that was conducive to division. So I don't exactly know why that result had been misunderstood at first. Maybe somebody had a cancerous cell line and so they got the wrong idea and it just spread, but Hayflick checked it and it turned out to be false. It turned out there was a number of cell divisions that healthy cells would go through, and then they'd stop. The mechanism was not obvious to Hayflick, but later it became clearer and clearer that the mechanism was these sequences at the ends of chromosomes which shorten each time the cell divides. And the implication was that, potentially, this was a cause of what we call “senescence”. What in common parlance would often be called “aging”, the tendency to grow feeble and inefficient with age. If your cells are each in a cell line and that line has a fixed number of times that it can replace itself before it has to stop, then some point your repair program starts to fail. And that repair program, failing across the body, looks like what you would expect aging—aging follows the pattern you would expect if cell lines one-by-one stopped being able to replace themselves. So— | ||
'''Eric:''' We know that there's a special sort of a, I don't want to call it cell line cause you keep correcting me for every tiny mistake I make in speech. But, if we divide | '''Eric:''' We know that there's a special sort of a, I don't want to call it cell line cause you keep correcting me for every tiny mistake I make in speech. But, if we divide our body into two kinds of cells, soma and germ, where germ lines are that which has a hope of immortality through reproduction, then it's the somatic cells that have finite limits on their ability to undergo mitosis and cellular repair and whatnot. | ||
(00:58:25) | (00:58:25) | ||