Flowers swap genes, according to articles in ScienceNOW 13 Nov 2008 and Science, vol. 322, p1116, 14 Nov 2008. Three hundred years ago a yellow flowered weed,Senecio squalidus, was brought to the UK. The plant became known as Oxford ragwort and was similar to a plant named Senecio vulgaris, a weed otherwise known as common groundsel. Common groundsel had small compact flowers without petals. After the introduction of Oxford ragwort a new variety of common groundsel appeared with showy petals. British scientists have studied the genes for petal formation in the old and new groundsels and compared them with Oxford ragwort. They found the newer groundsel with petals had genes almost identical to the Oxford ragwort. This is a “rare documented example of beneficial genetic flow between species”.
The researchers suggest the common groundsel lost its petals during evolution and regained them by gene transfer when it hybridised with Oxford ragwort. Loren Rieseberg, an evolutionary biologist at the University of British Columbia in Vancouver, Canada, commented that re-incorporating lost genes “may represent a common theme in plant evolution”. The groundsel plants whose flowers had petals spread rapidly. Enrico Coen, a geneticist at the John Innes Centre in Norwich, UK, who took part in the study, commented that the flowers with petals had an evolutionary advantage over petal-less varieties. Groundsel flowers without petals tend to be self-fertilised, but those with petals are often cross pollinated with other flowers. This increases the diversity in the seeds, enabling them to cope with a variety of conditions.
Editorial Comment: The loss of genes and the regaining of them is change, but it is not evolution. No new genetic information ‘evolved’ when ragwort and groundsel hybridised. For evolution to occur, new genes need to be made so that living organisms have characteristics that have not occurred in living things before. The fact that these two plants can cross breed naturally, and have fertile offspring, indicates the two species are really part of one kind, and the transfer of genes is simply a redistribution of original genes within one kind. The self-pollination of the petal-less groundsel is a good example of an inbuilt back-up system that enabled the plants to survive. Backup systems are good evidence for plan and purpose, rather than chance random processes. Altogether, these flowers are good evidence that plants were created according to their kinds, just as Genesis describes. The loss of genes is the opposite of evolution, but fits with the Biblical history of the world that started out perfect, but has degenerated. (Ref. botany, genetics, flora)
Evidence News 12 December 2008