N.Wells
Posts: 1836
Joined: Oct. 2005
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| Quote (GaryGaulin @ Aug. 07 2015,18:38) | | Quote (N.Wells @ Aug. 07 2015,09:18) | | No one has said that chemical species are not a scientifically valid concept, but they are not in any way equivalent to biological species. |
For that to be true the genetic chemicals/molecules of viruses and bacteria must be the same molecular species, which infers that all living things are likewise the same biological species.
Although the following from SequentiX does not take the phrase "molecular species" as literally as the theory must it's good evidence that the two are very related:
| Quote | Molecular identification
Our customer service:
Molecular species identification
Molecular determination of organisms causing diseases (pathogens)
Depending on the problem we analyse marker gene sequences (e.g. 16S rDNA or 18S rDNA, SSU rDNA genes) or highly variable DNA regions (e.g. ITS regions = internal transcribed spacer regions)
DNA sequence alignment using sequences published in public database (GenBank) [read more ...}
Reconstruction of evolutionary relationships or genetic relatedness to known organisms [read more ...}
Phylogenetic studies and reconstruction of the evolution
If desired we can classify the sequences using a molecular species concept
Our customers provide:
Organic samples or sequences (GenBank, FASTA, …)
What is a "molecular species identification"?
This is a simple approach to explain why we can use DNA for investigating the relatedness of organisms.
All organisms contain DNA (desoxy-ribonucleic acid) which consists out of coding regions (genes) and non-coding regions (spacers and other regions).
Genes contain information on the structure of RNAs (ribonucleic acid) and most RNAs are translated into protein sequences by the cells. Proteins give organisms functionality and structure. Therefore, organisms are quite sensible with respect to changes in their fundamental units, their genes. This is the reason why genes are quite stable or in other words: changes in gene structure can influence the fitness of the cell in a disadvantageous way.
Certain genes (e.g. the SSU rRNA genes) occure in all organisms and, therefore, can be used to compare these organisms on a molecular level. One can even reconstruct the evolution of organisms using comparative gene analysis.
In other regions of genomes, e.g. spacer regions, changes can be quite dramatic without influencing the fitness of the organisms. These regions can be used to compare closely related organisms, e.g. populations of a species, where most of the gene sequences are identical or too similar to yield a sufficient discrimination. |
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Hahahahahahaha!
Gary, it's priceless the way you double-down on nonsense and try to babble your way out of trouble. It never works!!
Your assertion that, "For that to be true the genetic chemicals/molecules of viruses and bacteria must be the same molecular species, which infers that all living things are likewise the same biological species" is simply rubbish. The one does not imply or require the other. They are unrelated.
Your second point is even more ludicrous. What the company is offering is identification of biological species by biomolecular analysis, not analysis of "molecular species" and cladistic analysis of the results, including identification of species by means of differences in DNA sequences. When they say "molecular species concept" and "molecular species identification" they are referring to identification of biological species by means of molecular analysis, i.e. using molecular criteria. In biology a species is (ideally) a group of organisms that can interbreed (although there are complications in terms of hybrids between species, with varying degrees of viability and fertility, and in terms of populations that can interbreed in captivity but which typically don't in the wild). This company is merely proposing to identify species by genetic differences rather than interbreeding experiments, which is a standard enough alternative to the biological species concept. In contrast, in chemistry, a chemical species has nothing to do with reproduction and interbreeding, but is merely a collection of atoms / molecules with the same shape and potential energy at least on the time scale of the observation (so all the atoms in a gold ingot are a single species, and all the molecules in a glass of pure water are another single species). Complications in chemical species include such things as conformational isomers that interconvert slowly, and molecules that are the same except for containing different isotopes. Nothing about reproduction, nothing about hybrids, nothing about biological evolution.
| Quote | The Darwinian "Modes of Speciation" are based on environmental factors that in this theory do not help model the molecular systematics that in reality do all the speciating. Example:
https://bioteaching.wordpress.com/2012.......ciation
Regardless of being real or virtual an "environment" is simply a place where whatever happens happens, not what causes speciation.
There is no place in the theory for words and phrases that explain nothing at all about how the model works. It would be inappropriate for this theory to include outside observations that do not explain how the molecular level systems work. Including that would amount to giving the impression that a pile of wonderful sounding science words like "prezygotic" and "postzygotic" explain how zygotes and their speciation mechanisms work. |
I was referring to evolution and M.J.D. White, not Darwin. While it is true that Darwin did not consider any genetic or chromosomal mechanisms in speciation (because he did not know about genes and DNA), if you actually went and read M.J.D. White's book (which I've suggested you do several times in the past), you wouldn't end up blathering lies and ignorance about speciation mechanisms covered in modern evolutionary theory. Some drivers of speciation are environmental, and others are not. Both types are well documented, unlike your drivel.
The ratio between how much you embarrass yourself with your scientific pronouncements and how unaware you are of the embarrassment is astonishing.
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