polyploidy

Researchers studied the thale cress (an Arabadopsis relative) which can have either a single or a double genome. Genome doubling is not good news: “It’s almost always a bad thing to have too much DNA, but we think that sometimes it makes for a ‘hopeful monster’ that just might flourish.” They seem to have found one: “These tough little plants can become little genetic adaptation machines which allows them to invade hostile environments and even thrive where others can’t. In fact, a large proportion of the most invasive plant species in the world are genome doubled, so we hypothesised that there are adaptations that occur as a result of genome duplication that we can focus on and find the genes Read More ›

From ScienceDaily: Many wild and cultivated plants arise through the combination of two different species. The genome of these so-called polyploid species often consists of a quadruple set of chromosomes — a double set for each parental species — and thus has about twice as many genes as the original species. About 50 years ago, evolutionary biologists postulated that this process drives evolution, leading to new species. Due to the size and complexity of such genomes, however, proving this theory on a genetic level has been difficult. Arabidopsis kamchatica arose through the natural hybridization of the two parental species A. halleri and A. lyrata between 65,000 and 145,000 years ago. With 450 million base pairs, its genome is somewhat small Read More ›