Plant Evolution in the Act

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“Evolution in the act” claim biologists, according to a report in ScienceDaily 18 March 2011. Scientists at University of Florida (UF) have studied a plant named Tragopogon miscellus, a species of daisy that originated when two species introduced from Europe cross bred and produced hybrid offspring. This natural hybridisation had happened before in Europe but the offspring never did well. The American hybrids were larger and spread quickly because the hybridisation process doubled the number of chromosomes. To confirm this, the researchers made artificial hybrids with double the chromosomes. They expected the hybrids to show a combination of the parent plants characteristics, but they found greater variation in subsequent generations. Richard Buggs, who worked on the study, explained “What we found was a surprise. It's as if hybridization and chromosome doubling hit a reset button on gene expression, turning them all on - this could allow subsequent generations to experiment by switching off different genes.” Doug Soltis, a professor in UF's biology department and study co-author commented: “We caught evolution in the act. New and diverse patterns of gene expression may allow the new species to rapidly adapt in new environments.”

ScienceDaily

Editorial Comment: New plants with doubled sets of chromosomes occasionally occur naturally (as in this case) or can be made by deliberate manipulation using chemicals such as colchicines. The chromosome multiplying process has been labelled ‘polyploidy’. The most obvious result of having a “doubled chromosome” number is that these offspring can no longer interbreed with the parent plants, so technically they are labelled a new species, but no evolution has occurred. The recombination of genes brought about by such chromosome doubling has brought out genetic variation that was already built in, but no new genes have come about. So these new and diverse patterns of gene expression are not evolution, even though we can and do artificially use such techniques for increasing size and number of leaves or petals.

As this study shows, new species can come about by genes being regrouped and redistributed, but despite the hope of evolutionists that new genes might come about from such a process – none have been observed to happen in the hundred years we have been seriously watching such crosses, and science is about observing the real world – not the theoretical one. In the words of this editor’s Genetics professor at Queensland University – polyploidy is an evolutionary dead end. Hybridisation and chromosome doubling show us that the origin of species is not the same as evolution. Just like natural selection, speciation by chromosome multiplication is a real biological process, but it is not evolution. (Ref. botany, genetics, tetraploid)

Evidence News 13 April 2011

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