If you are using the definition of reproductive isolation, although this is often not used, as shown by the recent announcement that African elephants are 2 species even though they interbreed in the wild.
In plants, but not in animals (possibly with rare exceptions), the doubling of all the chromosomes may result in an individual which can no longer interbreed with the parent type—this is called polyploidy . Although this may technically be called a new species, because of the reproductive isolation, no new information has been produced, just repetitious doubling of existing information. If a malfunction in a printing press caused a book to be printed with every page doubled, it would not be more informative than the proper book. (Brave students of evolutionary professors might like to ask whether they would get extra marks for handing in two copies of the same assignment.) Ref
Note that, as I’ve said elsewhere, speciation is not a problem for YEC. It explains how the small number of Kinds on Noah’s Ark could have produce the many species we have today, and why they are grouped into distinct families (in the common rather than the taxonomic sense)
The evidence for this is doubtful. It is far more likely that extra copies would be silenced and degenerate.
Ohno suggests that ‘gene duplication is the only means by which a new gene can arise’. This seems to me to be a problem since the first gene must have arisen without duplication and hundreds are required for even the simplest viable organism.
The main evidence for duplication and exaptation is the existence of gene families but the existence of gene families is also consistent with a designer. If expressed in the form;
Evolution theory predicts that duplication and exaptation will result in gene families.
We find gene families.
Therefore these evolved
it becomes the logically fallacy of affirming the consequent.
.
Gene families are consistent with evolution theory but
that does not exclude other explanations
it still needs to be shown that duplication and exaptation is sufficient to explain what it is supposed to explain.
No detriment? Perhaps that may be so in some cases but more often it is harmful.
Spontaneous duplication of the mammalian genome occurs in approximately 1% of fertilizations. Although one or more whole genome duplications are believed to have influenced vertebrate evolution, polyploidy of contemporary mammals is generally incompatible with normal development and function of all but a few tissues. Eakin and Behringer
Even in plants polyploidy is not always at no detriment.
The specific effects of polyploidy depend on the environment and the plant. Polyploidy increases cell size, causing a reduction of the surface-to-volume ratio that can reduce the rate of some cell functions, including metabolism and growth. Conversely, some polyploids are more tolerant to drought and nutrient-deficient soils. In addition, some polyploids have greater resistance to pests and pathogens. However, in all of these cases, a fitness cost exists, meaning that in many environments polyploidy is a disadvantage. Ref
Even where polyploidy is tolerated it is far from established that it produces significant change.
De Vries had assumed that tetraploid Oenethera plants would ‘breed true’, forming a distinct species. However, the tetraploid specimens of Oenothera that de Vries and other botanists cultivated did not form their own self-perpetuating populations, requiring constant special care and consistently generating a range of chromosome sets (diploid, triploid, tetraploid, etc.) in their offspring. Ref
Epulopiscium fishelsoni carries 25 times as much DNA as a human cell, and one of its genes has been duplicated 85,000 times yet it is still a bacterium. Ref
I meant for gene or part of a gene duplication, but whole genome duplication is perhaps even more interesting. Doubling the whole genome is quite a bit more rare but there are several documented cases as mentioned above. While I appreciate the desire to correct the ‘no detriment’ phrase, it is very well established that both gene duplication and whole genome duplication can provide positive effects for a population.
It’s not ‘the engine’ for evolution, but rather one of the several mechanisms through which changes can occur within populations from generation to generation. Also Bergman writes:
For example, the theory predicts a positive correlation between organismal complexity and gene number, genome size and/or chromosome number.
That’s not even true. That reminds me of the DAP nonsense (note: if you included onions on the graph or lungfish it would defeat the entire purpose):
Writing things that aren’t even true of your opponent would be a strawman.
African elephants were declared to be two species in ~2010. However there is new evidence that they do interbreed, here, although that’s not the article I found several months ago. I think the following might be it;
Experts have recognised for over a century that savanna and forest elephants are capable of mating and producing hybrids. This was – and still is – one of the key reasons why so many refuse to recognise forest elephants.
“They can interbreed and produce viable offspring,” said Julian Blanc with the CITES Program for Monitoring the Illegal Killing of Elephants (MIKE). “There are known areas of hybridisation, such as Garamba National Park in the Democratic Republic of the Congo. The Gaurdian.
