BTW, I don't count artificial selection as part of natural biological evolution.https://klimestesvena.ga/nothing-shall-be-impossible.php
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The issue here is not whether epigenetics, hybridization, and symbiosis occur, it's whether their relative frequency is sufficient to count them as common contributors to change in the frequencies of alleles in a population. In other words, should they be incorporated into standard evolutionary theory or should each event be treated as one-off examples in the history of life? Of course, the authors are sweeping the hybridization issue under the polyploidy umbrella, and I can't get further information at the moment without buying the article.
I'm not trying to say hybridization is a more important source of variation in plants than is mutation within lineages. Nonetheless, it's big. One can quibble about where the hybridization occurs in relationship to speciation itself, but I think two things are important here. First, it seems to me that selection against hybridization can occur only after speciation has happened and the resulting offspring are of low fitness.
Of course, inability to hybridize can develop accidentally, too, and can sometimes actually be the cause of the speciation. Second, I think that in plants there may not be the same selection pressure for preventing hybridization as there is in vertebrates. Most individual plants produce a lot more offspring than individual vertebrates, and the seeds produced by one maternal plants have several different fathers.
THE MYSTERIOUS WORLD OF THE HUMAN GENOME
So "wasting" a few as hybrids may have low cost, and sometimes those hybrids will pay off. Plants can't move to seek a better environment; offspring might benefit from having a set of genes that would have been harmful in the parent in its environment.
Some plants seem set up for serious hybridization. The variable biological unit we call Kentucky Bluegrass Poa pratensis for example, consists of plants that share maternal genetic material but gain additional variation through hybridization; the offspring of hybridization join the interbreeding Poa pratensis unit.
Poa pratensis also sets seed apomictically, without sex. I should go have breakfast and stop rambling. Big deal. All vertebrates have also undergone at least two rounds of polyploidization, and teleosts had undergone three. Hybridization is so important in some plants I work with that my view can become biased. Speaking of another not-so-candid admission of the inadequacy of the theory, an exciting new concept emerges.
Highly educated minds never underestimate the power of relentless inculcation consciously piss themselves away, but in the dark and naked recesses of mutant minds, the doubts persist. And they damn well should.
From an intelligent designer? Of these laypeople, some haven't touched a book on science for 20 years or more. I am one of the latter group. Sure, going by your scathing review, there seem to be generalizations and oversimplifications in this book, but in order to appeal to the reader like me, scientific accuracy and exactitude may not always work. For with accuracy and exactitude come technical jargon too. And jargon often puts off the lay reader. I hope you get what I'm saying. I guess the author has taken some liberties in order to appeal to a more general audience.
And as far as the 'epigentics' topic is concerned, what I've seen from my readings, albeit general in nature, is that there are clearly two sides of the fence: those for epigeenetics and those staunchly against. I guess you might belong to the latter. But I'm not going to dispute you. View community. Announcements Message board Help. Register Log in. Search Trade Me.
Listing : Ngaruawahia, Waikato, NZ. View Count: 4. Ping Add this item to Cart for a combined free shipping deal. The human genome is indeed a mysterious world, but, as this fascinating book shows, its vital secrets are now being uncovered. The latest studies are revealing exciting new discoveries, such as how the DNA and related chemical compounds in our cells work together to direct the processes of life.
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The Mysterious World of the Human Genome by Frank Ryan | | Booktopia
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