<https://pt.coursera.org/lecture/emergence-of-life/2-1-the-scientific-inquiry-of-carl-woese-8wuej#lecture>
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"[MUSIC] I'm Bruce Fouke from the University of Illinois in Urbana-Champaign. So when we look at the historical development of the philosophy of science and evolutionary biology, there are some fundamental, very large names, very well known names of people that you do know. People like Socrates, people like Darwin. These are household names. They occur in all aspects of our society, and they're recognized as being pioneers and people who fundamentally set the stage for understanding how science works and for giving us some understanding of how evolutionary biology works. However, the field of evolutionary biology is rapidly moving forward. It's driven in large part by technological developments, the ability to analyze DNA, which we haven't had before. And it's moving forward extremely fast. And therefore, the most fundamental conceptual ideas of evolutionary biology are just being published now. They're not in most textbooks, they're not being discussed around the kitchen table, yet, this is where the field is going. So what we are going to do in our journey of evolutionary biology together. Is to recognize these massive accomplishments by the scientists that you don't know of now, who will be household names in the near future. And I think especially important to us for this Evolutionary Biology course is the history of Professor Carl Woese and his research here at the University of Illinois in Urbana-Champaign. Professor Woese began with our true grassroots movement on campus in the Department of Microbiology. And started to use new tools that hadn't been applied before. And really set out on this journey to try to find a universal, a unifying theme of how to look at this great diversity of life we have on planet. What are the essential elements of that life that let us compare all life to each other and understand what the fundamental structure of life is? [MUSIC] >> So we found right away, that all of the nucleotide catalogs for these Eukaryotes had a common signature, which was different than the signature for the bacteria. Well, here comes this pattern in a wall and we're reading, this is from the first Archean. And I said, where are the bacterial spots that are unique for bacteria? They're not here. And then I worked my way up in what's called the G Isopleth, it contains no u. And here I came to another signature of a nucleotide that is characteristic of all bacteria. And it wasn't there. And this continued and my excitement grew, what was this beast? And so, I went all through it and the first thought was, this isn't even prokaryote. That was a very exciting day. >> And so his work for the first several years, it was very hard to get funded. It was something that a lot of people flat out rejected or were very cool to. And he had a lot of, he was ostracized a lot by the community. And this played out both in terms of getting students, having grants, allowing papers to be published. But then eventually he was able to have some fundamental benchmark papers published. And the one that we're going to be going back to later on and discussing in more detail is the paper where he puts out, holistically, a structure for life based on the composition of specific genes and their frequency and occurrence within different organisms through geological time. >> Carlos, he had done his analysis already and based on a few differences which were very, very significant. And he worked, obviously, very, very precisely. And as I know now, of course, a very honest scientist. And so he found, really, that these organisms which all had been misclassified by the old chemical thing. That those were placed in a different, separate top in the tree of life. And by his method, and this was for me, it was unbelievable that you really, that he seemed to be able to trace back microbial life almost to its roots. At that time, nobody had thought this would ever be possible. And so this was so exciting. >> He identified the gene, the 16S ribosomal RNA gene sequence that could be compared in all things that are living. And that comparison then yields evolutionary relatedness and became finally the tool that fundamentally changed science, and let us have a structure for science and a structure for biology. >> Before then, before Woese, 1977, the ideas were wrong, and still are wrong in our text books, as you know, in many regards. And third, a process of evolution that we don't know about yet, but, we have a much better idea of what that was in the context of Woese's big tree. So, I would argue, again, before 1977 biology at large was not a science, and when Woese put in place the experimental grounding, that made biology a science. >> Now, before professor Woese did his work, the general paradigm, the general thinking of the large scale concept of, well, what's the general structure of life on Earth? How many types of life are there? The answer was universally, two. There are prokaryote's which are the single cell organisms, and then there are the eukaryote's which are the multiple cell organisms, and that's all there was. And for decades once that was established people thought, well, the answer's there. That's what the structure of life is, and we need to move forward. And anyone who challenges that is a heretic who should be figuratively burned at the stake. So that's what Professor Woese was against. And then as his work matured and refined, he started seeing this pattern of the structure of life. And it wasn't two-fold, it was three-fold. So instead of having two branches of life, the prokaryotes and the eukaryotes, we had three branches of life, the bacteria, the archaea, and the eukarya. So that three-pronged tree of life is the fundamental structure on which we are going to base the rest of the course. At that moment of publication, it changed, fundamentally, how science is done as it relates to biology throughout the planet. And everything was different from that moment forward. So that's one of the goals of the course, is to understand, that revelation, and how that revelation now is tied to making predictions and understanding, not only of the historical evolutionary biology, but also the prediction of where biology's going to go in the future. [MUSIC]"
<https://pt.coursera.org/lecture/emergence-of-life/2-1-the-scientific-inquiry-of-carl-woese-8wuej>