I asked for your definition of a species in order to have a productive conversation because it can vary even among scientists. Some scientists consider Helacyton gartleri, derived from Helen Lacks 60 years ago, as a new species, others say it is still Homo sapien.HeLa cells are 1) derived from human cells in lab and not by evolution. Thus it contributes nothing to evolution through random mutation. 2) If such a cell is a new human species then every single specialized (as well as stem) cell in human body is a new human species and I must be composed of about 300 hundred different species each one containing billions of individuals.
I think it is possible you missed the point. HeLa cells are distinctly different. For example, HeLa ATCC-CCL2 is variably multiploid with 51-179 total chromosomes. Chromosome 3 does not exist. The long arm of chromosome 3 is fused to the long arm of chromosome 1; the short arm of chromosome 3 is fused to the long arm of chromosome 5. The small arm of chromosome 5 is duplicated at the other side of the centromere to form a small isochromosome. The long arm of chromosome 11 is fused to an arm of chromosome 19. And these changes are the gross ones that can be observed in a light microscope (Lavappa et al, 1976) http://www.nature.com/nature/journal/v259/n5540/abs/259211a0.html
That is exactly what I said in previous pot: evolutionary scientists don't even have a clearly defined notion of species. How can you talk about species evolution if you don't know what species is? That is not my problem. It adds to your problem. I already gave you how I would change my reasoning by simple introducing clear terms, without ever referring to vagueness of "species", to which you gave me wrong answer.
This is not a problem. Genetic isolation (absence of interbreeding) in higher organisms and slow gene transference in lower organisms (either genetic or geographical isolation) suffices. You are the one that brought up species:
For sure, there has never been any observation of new species formation in spite of very intensive selective "experiments" by humans.
But you clearly do not want this statement challenged, so I won't.
Problem with your reasoning is twofold at least: 1) If you giving me such examples as an examples of evolution, then huge changes (like acquiring genes for flagella) occur in a matter of minutes or hours, or however long it takes for different e.coli to exchange genetic material. If such changes happen so fast we should be seeing all species turning into different species in a matter of days or months (of course this reasoning only is extrapolation of your reasoning by bringing in these examples).
There is no reasoning on my part. I just stated the facts. Your problem (not mine) is that you have no definition for a species that you are willing to accept so there is no response possible, only facts. There is substantial and rapid exchange of genetic information (like the genes necessary for the formation of flagella) between E. coli
because these individual cells are not genetically or physically isolated from each other. However there is also substantial, but slow, exchange of genes between different "species", "genera" and "classes" of bacteria. For example the transducing bacteriophage SN-T infects bacteria belonging to the class Gammaproteobacteria (Shigella flexneri, Proteus vulgaris, Pseudomonas aeruginosa, Escherichia coli
), Alphaproteobacteria (Rhodospirillum rubrum
) and class Betaproteobacteria (Sphaerotilus natans
). (Transducing bacteriophage occasionally package bacterial DNA into their capsids, usually by mistake, which of course doesn't kill the next host when they inject the non-viral DNA.) (Source for SN-T info: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1317401/
) There are also broad-range plasmids that are compatible with a wide range of bacteria and gene transfer between the kingdoms bacteria and archaea is also evident (Source: http://preview.ncbi.nlm.nih.gov/pubmed/19271200
). Current estimates are that approximately 70% of genes in any given bacterium arrived by horizontal gene transfer.
Your question about all species turning into different species can't be answered because species is not defined. You should not be dogmatic about how evolution works. Prokaryotes (archaea and bacteria) exchange genetic information promiscuously with cohabitation being a major component in regard to the rate of exchange.
I think you will like this quote from Eugene Koonin (source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2784144/
), "The biological universe seen through the lens of genomics is a far cry from the orderly, rather simple picture envisioned by Darwin and the creators of the Modern Synthesis. The biosphere is dominated, in terms of both physical abundance and genetic diversity, by ‘primitive’ life forms, prokaryotes and viruses. These ubiquitous organisms evolve in ways unimaginable and unforeseen in classical evolutionary biology. Above all, it is an extremely dynamic world where horizontal gene transfer (HGT) is not a rarity but the regular way of existence, and mobile genetic elements that are vehicles of HGT (viruses, plasmids, transposons and more) are ubiquitous. We now think of the entire world of prokaryotes as a single, huge network of interconnected gene pools, and the notion of the prokaryotic pangenome is definitely here to stay. Although HGT is partially curtailed in eukaryotes, especially, the multicellular plants and animals, multiple endosymbioses accompanied by massive gene transfer were key to the evolution and indeed the very origin of eukaryotes. Moreover, most eukaryotic genomes teem with mobile elements which make them no less dynamic than the prokaryotic pangenome. The discovery of the all-encompassing genomic mobility puts to rest the traditional concept of the Tree of Life that has to be replaced by a network of vertical and horizontal gene fluxes. It is important to note, however, that evolution of individual genes still can be represented with trees, and search for trends in the ‘Forest of Life’ comprised of these gene trees could still reveal order in the historic flow of genetic information."
Also please look at Table 1 in the above cited paper: "The fate of the central tenets of (neo)Darwinism in the post-genomic era". This conversation should be about evolution and not Darwinism.
So I will ask you: why don't we see humans change for say 5000 years? Your answer is, it's not enough time for a human to transform into a new species? I ask again: did you not just gave me examples of unicellular things turning into multicelllar in a blink? Well, you should not have brought this examples at all.
Not a blink exactly, but I believe this question is now addressed above.
2) Of course you gave me examples where things happen as a result of very very cleverly designed structure of cell communication and exchange of genetic material. If you've paid attention I was actually saying you can't get such cellular communication and exchange of genetic material in cells that did not have all these to start with. Now you have to explain not only how one bacteria without flagella evolved into bacteria with flagella but also how bacteria acquired the property of genetic material exchange within the species and across the species which in turn requires lots of genes working in amazing cooperation. Can you do that?
The first part of point (2) has been answered in one aspect, all prokaryotes have the ability to obtain genetic information from their surroundings. As far as how the first flagellum arose, I probably could specify a pathway for evolution from protein homologues and my thoughts about it. But I am not particularly interested in how flagella evolved into being. You might want to read "From The Origin of Species to the origin of bacterial flagella" in Nature Reviews Microbiology 4, 784-790 (2006) http://www.nature.com/nrmicro/journal/v4/n10/full/nrmicro1493.html
The other reason that I feel answering this question is a waste of my time is that I have seen no convincing or suggestive scenario for the creation of life on earth (abiogenesis).
See my prior posts for my thoughts on this topic:http://www.orthodoxchristianity.net/forum/index.php/topic,4959.msg534740.html#msg534740http://www.orthodoxchristianity.net/forum/index.php/topic,4959.msg535055.html#msg535055http://www.orthodoxchristianity.net/forum/index.php/topic,4959.msg535427.html#msg535427
N, not that. Simply put the problem is this: obligate intracellular parasites, I say, must have evolved through simplification of already existing facultative cell who could exist outside acell. And of course the whole my assumption is based on anther assumption that Darwinism is true. Mina is saying this assumption is not right and he's doing this to avoid artificially introduced notion of "evolving, going up the ladder". If my assumption is not right then obligate intracellular cell evolved (got more and more complex) inside a cell. I'd like to hear how.
I am not sure what you are asking here and I do not have time to go back to previous posts to figure out what you are getting at. I can only again suggest looking at Table 1. "The fate of the central tenets of (neo)Darwinism in the post-genomic era". Darwinism is only partially correct. From the cited table: "There is no consistent trend towards increasing complexity and no progress in evolution".
Pardon the typos if you find any.