tas8831
Well-Known Member
Short answer - NO.
Some Friday morning ramblings...
Many creationists seem to think (and many insist) that an alteration in phenotype REQUIRES some large number of mutations, or a new one for me - changes in 'genome architecture' or 'genome structure.'
I am still waiting for a scientific definition of "genome architecture" that is relevant to phenotype.
The often wacky assertions put forth by creationists on these issues exposes a general ignorance among the them regarding the relationship between genotype and phenotype, between mutations and changes in phenotype, etc.
The short answer for this is - there is generally no 1-to-1 relationship between mutation and phenotype, and in terms of morphology, there is probably very little if any 1-to-1 relationship between it and genes*..
A few haphazardly listed points about this:
1. They forget/never knew about regulatory sequence. The timing and extent of gene expression can alter morphology without requiring major changes in DNA or 'genome architecture', whatever is meant by that (yes, I know that is a real thing, but given how some creationists 'define' terms as they see fit, I see no reason to think that creationists use the ACTUAL definitions of such terms). Mutations involving regulatory regions can alter the timing/extent of expression.
2. They ignore/dismiss the fact that morphology among, say terrestrial vertebrates, are different via degrees, not 'kinds'. That is - our anatomy, in particular our gross morphology, differs from that of, say, a dog by degree, not kind. Our skeletons, for example, are basically the same in terms of numbers of bones and such - we differ primarily by the shapes of individual bones (which can be affected by what is mentioned above). Thus no "brand new genes" or "genome architecture changes" are needed for such variation. Which leads into
3. the notion that evolutionists think all genes are identical. Yes, a creationist actually wrote this. No, we don't think that at all. Obviously there are differences in genes or we would all be ONE thing. Duh.
I'm betting that creationists that think this way also believe that gene duplications do not add information... Oh well...
4. Which leads me to the muntjacs.
View attachment 31109
Allow me to demolish the "changes in genome architecture" argument:
That is, the 'architecture' and numbers of chromosomes and amount of DNA are less important than the genic content of the genomes in terms of viability, morphology, physiology, infertility, etc.
Another creationist argument bites the dust.
*I am referring to the insinuations/assertions that 'new genes' or 'changes in genome architecture' are needed to alter morphology.
Some Friday morning ramblings...
Many creationists seem to think (and many insist) that an alteration in phenotype REQUIRES some large number of mutations, or a new one for me - changes in 'genome architecture' or 'genome structure.'
I am still waiting for a scientific definition of "genome architecture" that is relevant to phenotype.
The often wacky assertions put forth by creationists on these issues exposes a general ignorance among the them regarding the relationship between genotype and phenotype, between mutations and changes in phenotype, etc.
The short answer for this is - there is generally no 1-to-1 relationship between mutation and phenotype, and in terms of morphology, there is probably very little if any 1-to-1 relationship between it and genes*..
A few haphazardly listed points about this:
1. They forget/never knew about regulatory sequence. The timing and extent of gene expression can alter morphology without requiring major changes in DNA or 'genome architecture', whatever is meant by that (yes, I know that is a real thing, but given how some creationists 'define' terms as they see fit, I see no reason to think that creationists use the ACTUAL definitions of such terms). Mutations involving regulatory regions can alter the timing/extent of expression.
2. They ignore/dismiss the fact that morphology among, say terrestrial vertebrates, are different via degrees, not 'kinds'. That is - our anatomy, in particular our gross morphology, differs from that of, say, a dog by degree, not kind. Our skeletons, for example, are basically the same in terms of numbers of bones and such - we differ primarily by the shapes of individual bones (which can be affected by what is mentioned above). Thus no "brand new genes" or "genome architecture changes" are needed for such variation. Which leads into
3. the notion that evolutionists think all genes are identical. Yes, a creationist actually wrote this. No, we don't think that at all. Obviously there are differences in genes or we would all be ONE thing. Duh.
I'm betting that creationists that think this way also believe that gene duplications do not add information... Oh well...
4. Which leads me to the muntjacs.
View attachment 31109
Allow me to demolish the "changes in genome architecture" argument:
Genomes of Placental Mammals
The variation in genome organization and size is striking. The Indian barking deer, Muntiacus , has only three pairs of chromosomes, whereas the black rhinoceros, Diceros bicornis, has 67 pairs. Genome size varies from 1650 Mb in the Italian bat Miniopterus schreibersi to 5500 Mb in the South African aardvark, Orcyteropus afer. In short evolutionary time spans, these differences in genome size have little effect on embryological development, morphology, or physiology, as revealed by comparisons of the Indian muntjac, Muntiacus muntjac(2400 Mb), with its three pairs of chromosomes, and the Chinese muntjac, Muntiacus reevesi (2900 Mb), with its 23 pairs of chromosomes. Despite these different genome architectures and genome sizes, the species are morphologically similar and yield viable hybrids.
The variation in genome organization and size is striking. The Indian barking deer, Muntiacus , has only three pairs of chromosomes, whereas the black rhinoceros, Diceros bicornis, has 67 pairs. Genome size varies from 1650 Mb in the Italian bat Miniopterus schreibersi to 5500 Mb in the South African aardvark, Orcyteropus afer. In short evolutionary time spans, these differences in genome size have little effect on embryological development, morphology, or physiology, as revealed by comparisons of the Indian muntjac, Muntiacus muntjac(2400 Mb), with its three pairs of chromosomes, and the Chinese muntjac, Muntiacus reevesi (2900 Mb), with its 23 pairs of chromosomes. Despite these different genome architectures and genome sizes, the species are morphologically similar and yield viable hybrids.
That is, the 'architecture' and numbers of chromosomes and amount of DNA are less important than the genic content of the genomes in terms of viability, morphology, physiology, infertility, etc.
Another creationist argument bites the dust.
*I am referring to the insinuations/assertions that 'new genes' or 'changes in genome architecture' are needed to alter morphology.