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Recent Advances in Evolutionary Theory
OK. Let's see if I can get it right this time.
Are there people here (Botnst comes to mind) who know much about the advances in evolutionary theory from the past 30 years? Here's the crux: I was taught and have been perfectly comfortable accepting that time, randomness and survival of the fittest was the basis for evolutionary theory. Didn't all of us over the age of 35 or so learn that lighting in the early planet eventually produced amino acids which then bubbled in the air and ocean for a couple billion years until chance combination produced life? I'm serious. All you folks out there. Isn't that what you were taught and tend to still believe? Well, if you wrote a technical paper with that concept and submitted it to a respectable journal they would return it and have been doing so since 1980!! The earth is about 4.5 billion years old. Water formed about 3.8 billion years ago. The fossil record tell us life started about 3.5 billion years ago. And then that life remained basically constant until about 650 million years ago. This topic interests me. I would enjoy discussing it in greater detail if there are those who know about and are interested. If not, or if you think I'm trying to deceive or otherwise be disingenuous I'll not post more on the topic. I've read a bit about it but before I post more details I'll see what, if any, interest there is. Be well. |
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__________________
1977 300d 70k--sold 08 1985 300TD 185k+ 1984 307d 126k--sold 8/03 1985 409d 65k--sold 06 1984 300SD 315k--daughter's car 1979 300SD 122k--sold 2/11 1999 Fuso FG Expedition Camper 1993 GMC Sierra 6.5 TD 4x4 1982 Bluebird Wanderlodge CAT 3208--Sold 2/13 |
#3
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As I mentioned above and previously I have read about the matter since encountering Schroeder's book. I was asking for dialog. While evolutionary biologists have a number of theories it seems the field is much less certain of specifics than it claimed many decades ago. I found your earlier comment about meteor-seeding interesting.
Also, while reviewing the current state of knowledge, it appears that numerous hypothesis that can be partially supported exist but none of them rise to the level of being proven. This probably falls into a category you know more about, theory of knowledge of some such title, but how one makes the transition from hypothesis to accepted fact is easy (at least for me) to accept when dealing with laboratory-testable concepts but becomes less so with other investigations. |
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Last edited by sjh; 09-22-2011 at 10:19 PM. |
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Here are a couple set of quotes from the Nova show -
But natural selection is far from the full story of evolution. Many mutations can spread throughout an entire species thanks not to natural selection but through lucky rolls of the genetic dice. This so-called neutral evolution has been particularly important in shaping the parts of the genome that do not contain protein-coding genes. The past decade of research has confirmed that sex is indeed a potent force. But it's powerful in ways that Darwin could not have appreciated. Studies in the past few years have demonstrated that the sexual preference that females have for one kind of male over another is potent enough to carve an old species apart into several new ones. In the lakes of East Africa, for instance, sexual selection has driven the origin of hundreds of new species from fish that live and breed side by side. |
#6
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For starters, it is a fact that life evolves, that's what the fossil record, molecular genetics, geology and various lines of physical science research indicate.
Darwins theory was developed through the study of macroscopic phenomena. He simply did not have the tools necessary to devise a complete and testable theory. He developed a plausible conceptual model, given the facts available at the time. Thus, the field of evolutionary theory is extremely new in comparison to all of the other sciences once under the umbrella of 'natural philosophy.' Evolutionary theory has itself evolved as better tools have become available. The straight, linear sequences derived from fossil study have been enriched by the field of cladistics, which demonstrates relatedness by a multivariate search for parsimony. Molecular genetics, combined with cladistics, has resulted in a continuous upheaval in systematics. Taxonomic families have been shattered, whole new classifications derived. However, the new tools have generally confirmed the broader concepts of organic evolution. Those who believe that current scientific evolutionary dogma is inadequate can make a great name for themselves down through time for all of the end of time by demonstrating a more comprehensive, parsimonious and falsifiable theory that better explains the objective evidence. |
#7
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Quote:
You are quite right. The more I read I see it has greatly changed since the introduction I had to it as a youth. Here's more quotes from Nova which I found interesting - Scientists have found that fungi and animals share a closer ancestry than either does to plants. And since life was almost entirely single-celled for the first two billion years of its history, we must see the opening chapters of our biological history as a tapestry rather than a tree. |
#8
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An excellent and highly readable scientifically sound description of evolution with regards to the O2:CO2 gas ratio.
Out of Thin Air: Dinosaurs, Birds, and Earth's Ancient Atmosphere Peter Ward He has a graph in there of the gas ratio that should give all students of global warming reason to reflect on the known and unknown. |
#9
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Does it have a similar message to one of his other books?
Amazon.com: Under a Green Sky: Global Warming, the Mass Extinctions of the Past, and What They Can Tell Us About Our Future (9780061137914): Peter D. Ward: Books |
#10
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I didn't get that message from the book I read. Though he did concentrate on the huge impact that the changes in gas concentration had on the flourishing of live and it's occasional catastrophic collapses. Boom and bust cycles, according to Ward, are the source of many of the great changes in speciation and diversity over time.
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#11
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A few thoughts I have about this subject, in no way do i mean to argue with anyone.
-The fossil record is VERY incomplete, I have heard estimates that we only have fossils of less than 10% of the species that have existed at one time or another. -There are very few fossils older than ~600 million years ago that are well preserved enough to even be sure what they were. -I have heard from more than one person working in this field (teachers with Phds in paleontology, etc) that there are some lines of research that are not allowed. Basically when the majority decides something (like that the earth was at the center of the solar system, or that plate tectonics was not possible, etc) it does not go well for anyone who does any research or publishes papers that suggest they don't agree with the majority view. I do find this subject very interesting, I have taken several classes about such things. One thing I found interesting is that global warming (and high CO2) seems to have actually been good for life in general (diversity and amount of life) from past evidence. |
#12
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You really need to get a life.....from 12 posts so far (mine included) you have posted 6 times. I don't know about evolution but with you we could discuss Narcissism.
Narcissism - Wikipedia, the free encyclopedia
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Vivere senza rimpianti Despite the cost of living, have you noticed how popular it remains? |
#13
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Who died and left Padrino in charge of saying who needs to get a life?
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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC] ..I also have a 427 Cobra replica with an aluminum chassis. |
#14
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I enjoy the subject of evolution myself very much. I always read the articles in Smithsonian and National Geographic about it first.
__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC] ..I also have a 427 Cobra replica with an aluminum chassis. |
#15
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Yes, the fossil record is incomplete. It would be mind-boggling were it NOT incomplete.
The fossil record is biased toward structures that are hard and decay resistant like shells and bones. Fossilization has stringent mineralization requirements that pretty much restrict fossils to organisms found in aquatic or wetland situations. Fortunately, scientists have developed multiple, independent methods of inquiry. It is no coincidence that these enquiries generally converge. Current dogma (of whatever sort) generally forces scientists to look for explanations within normative parameters. It is the rare scientist who has the vision and fearlessness to overturn whatever is current dogma. Usually because current dogma happens to be the best explanation, given the evidence at hand. Every scientist worth his PhD dreams, in his heart of hearts, of being the lone figure who develops a Radical New Theory of Everything. At least they hold that dream early in their career. As the age, wisdom consumes their ambition and they realize taht there are lost of really smart scientists and they all harbor the same secret ambition. A paradigm-shifting discovery is far less common than the most precious ore. And there are many, many prospectors. |
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