In Why Evolution Is True , Coyne claims that primary speciation was observed in an experiment reported in Curiously, Coyne did not mention it in the book he co-authored with Orr, but his account of it is worth quoting in full:.
Paul Rainey and his colleagues at Oxford University placed a strain of the bacteria Pseudomonas fluorescens in a small vessel containing nutrient broth, and simply watched it. Oxygen concentration, for example, is highest on the top and lowest on the bottom. The smooth ancestral type persisted in the liquid environment in the middle. Each of the two new forms was genetically different from the ancestor, having evolved through mutation and natural selection to reproduce best in their respective environments.
Here, then, is not only evolution but speciation occurring in the lab: the ancestral form produced, and coexisted with, two ecologically different descendants, and in bacteria such forms are considered distinct species. Exaggerating the evidence to prop up Darwinism is not new. There was no net evolution, much less speciation.
When a booklet published by The U. So there are observed instances of secondary speciation — which is not what Darwinism needs — but no observed instances of primary speciation, not even in bacteria. British bacteriologist Alan H.
Bacteria, the simplest form of independent life, are ideal for this kind of study, with generation times of twenty to thirty minutes, and populations achieved after eighteen hours. But throughout years of the science of bacteriology, there is no evidence that one species of bacteria has changed into another. The actual evidence shows that major features of the fossil record are an embarrassment to Darwinian evolution; that early development in vertebrate embryos is more consistent with separate origins than with common ancestry; that non-coding DNA is fully functional, contrary to neo-Darwinian predictions; and that natural selection can accomplish nothing more than artificial selection — which is to say, minor changes within existing species.
Faced with such evidence, any other scientific theory would probably have been abandoned long ago. Judged by the normal criteria of empirical science, Darwinism is false. Its persists in spite of the evidence, and the eagerness of Darwin and his followers to defend it with theological arguments about creation and design suggests that its persistence has nothing to do with science at all.
Given accurate information and the freedom to exercise critical thinking, students could learn from Why Evolution Is True how Darwinists manipulate the evidence and mix it with theology to recycle a false theory that should have been discarded long ago. Fossils Coyne turns first to the fossil record. Vestiges and Bad Design Darwin argued in The Origin of Species that the widespread occurrence of vestigial organs—organs that may have once had a function but are now useless—is evidence against creation.
Notes Jerry A. Coyne, Why Evolution Is True, pp. Available online here. James W. Valentine, Stanley M. Awramik, Philip W. Liss, Jeffrey S. More information available online here.
Stephen C. Coyne, Why Evolution Is True, p. Wells, Icons of Evolution, pp. This and other Marx Brothers quotations are available online here. New York: Free Press, , pp. The passage quoted by Darwin is on p. Jane M. Press, Frederick B. Michael K.
Richardson, J. Hanken, M. Gooneratne, C. Pieau, A. Raynaud, L. Darwin, Charles. Kohtaro Fujihashi, J. McGhee, C. Lue, K. Beagley, T. Taga, T. But that tree drawn by Darwin was the first evolutionary tree of life. My book is about the history of that but more importantly about the way that image has been radically revised as a result of the discoveries we have made from genome sequencing in the last 40 years. The archaea are a third domain of life that was unknown to exist before It was a group of organisms thought to have been bacteria.
Through a microscope, they looked like bacteria, little bugs with no complex anatomy. But with genome sequencing they were revealed to be not only not bacteria, but more different from bacteria than they are from us in terms of their genomes.
He was a microbiologist at the University of Illinois, in Urbana, in the middle of the American prairie, working away during the late s and early s. He was deeply interested in the early history of life on Earth, going way back to the beginning of cellular and pre-cellular life close to 4 billion years ago. He decided the way to do it would be to go inside living cells, find a single molecule common to all forms of life, pull that molecule out, sequence its genomic letters, and then collect paragraphs of those letters for one organism and another and compare them to see who was related to whom, how distantly, how closely, and the way life had diverged over billions of years.
He then made the discovery that some of these creatures that looked like bacteria, were, in fact, not bacteria at all but the archaea , this third kingdom of life. That discovery got him on the front page of the New York Times on November 3, I wrote a previous book about emerging diseases, like Ebola, and much work has been done on that at Porton Down.
The particular bug is called shigella flexneri , and was isolated from a British soldier named Ernest Cable in during WWI, when he died in a hospital in France from dysentery, which killed a lot of soldiers. This specimen was tucked away at Porton Down until about a decade ago when one tube of the samples was pulled out, thawed, regrown in a laboratory by a team of scientists led by one Kate Baker, and its genome examined.
Lo and behold! One of the things they found out about this sample of bacteria was that it was already resistant to penicillin. But here was a bug killing a British soldier back in that already had resistance to that anti-bacterial substance, penicillium. Horizontal gene transfer is essentially sideways heredity. It can even go from one kingdom of life into another, sideways, across great barriers. That was thought to be undoable.
In fact, genes can go sideways across vast species boundaries. For instance, a gene for resistance to one kind of antibiotic in one form of bacteria, like staphylococcus, can move sideways into another, completely different form of bacteria, say, E.
This can happen not just in bacteria but also in animals, plants, and higher organisms, generally as a result of infection or parasitism. One example is a form of transposon. Big, complicated word. Who knows what lies ahead if we get a handle on dark matter, the origins of life, or even, pace Horgan, consciousness.
Secondly, I think Quammen is still correct that, all told, the successive discoveries surrounding Archaea, horizontal gene transfer, endosymbiosis, the microbiome and all the rest constitute a new view of life and a rewriting of the story of evolution, perspectives very different from those found in The Origin of Species.
Put simply, changes in quantity have produced a change in quality, and in my view we live in a different world now regarding our understandings of life and its meanderings. Scientists across a broad range of disciplines genetics, taxonomy, paleontology, etc. There is grandeur in this new view of life, so why force it into the Procrustean bed of nineteenth-century theorizing? Your friend, Jim. Further Reading :. Science, History and Truth at the Faculty Club.
Thomas Kuhn Wasn't So Bad. Mind-Body Problems free online book, also available as Kindle e-book and paperback. Don't tell the creationists, but scientists don't have a clue how life began. The views expressed are those of the author s and are not necessarily those of Scientific American. For many years, he wrote the immensely popular blog Cross Check for Scientific American. Follow John Horgan on Twitter. Already a subscriber?
Sign in. Thanks for reading Scientific American. Create your free account or Sign in to continue. In a paper published in late October in the Journal of the National Cancer Institute , Townsend and his Yale colleagues presented the results of their evolutionary analysis of mutations in cancers.
Cancer cells are rife with mutations, but only a small subset of those are functionally important to the cancer. The selection intensities reveal how important the different mutations are for driving growth in an individual case of cancer — and therefore which ones would be most promising as therapeutic targets. Although identifying the mutations undergoing the strongest selection is clearly useful and important, selection can also have subtle but important indirect effects on regions of the genome neighboring the target of selection.
One thing they discovered was an apparent correlation between the level of genetic variation and the rate of recombination at any specified region of the genome. Recombination is a process in which the maternal and paternal copies of chromosomes exchange blocks of DNA with each other during meiosis, the production of sperm and egg cells.
These recombinations shuffle genetic variation throughout the genome, splitting up alleles that might have previously been together. By , researchers could get whole-genome data from a variety of organisms, and they started to find this apparent correlation between levels of genetic variation and the rates of recombination everywhere, Kern said. That correlation meant that forces beyond direct purifying selection and neutral drift were creating differences in levels of variation across the genomic landscape.
Kern argues that the differences in the rates of recombination across the genome reveal a phenomenon called genetic hitchhiking. When beneficial alleles are closely linked to neighboring neutral mutations, natural selection tends to act on all of them as a unit.
Genetic hitchhiking meant that evolutionary geneticists suddenly had a whole new force called linked selection to worry about, Kern said. If only 10 percent of the genome is under direct selection in a population, then linked selection means that a much larger percentage — maybe 30 or 40 percent — might show its effects. Zhang points out that linked neutral mutations are still neutral. Kern agrees: The neutral mutations are still neutral — but they are not behaving as neutral theory would predict.
Recent human evolution is largely a history of migrations to new geographical locations where humans encountered new climates and pathogens to which they had to adapt. In , Kern published a paper showing that most human adaptations arose from existing genetic variation within the genome, not novel mutations that spread rapidly through the population.
Even so, only about 1 percent of the human genome actually codes for proteins, said Omar Cornejo , an evolutionary genomicist at Washington State University.
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