Duplication of hereditary information and its consequences

Scientists have discovered that plant lineages with multiple copies of their genetic information face higher extinction rates than their relatives. Competition with established, related diploid lineages renders polyploids susceptible to extinction. The research was headed by Dr Itay Mayrose, an assistant professor at the department of molecular biology and ecology of plants at Tel Aviv University in Israel.

Duplication of hereditary information is rare in animal evolution. But it is it is common in plants. Potatoes, coffee, bananas, peanuts, tobacco, wheat, oats and strawberries are a few examples of plants carrying multiple copies of their genetic material. This condition is called polyploidy. Most animals including humans are diploid. More than one-third of all existing plant species are polyploid.

The scientists looked at what are the advantages or disadvantages of going polyploid by making multiple copies of the entire genome and passing them on to the next generation? They analyzed more than 2,500 plant genomes with a computer-based, statistical approach. They found a trend that sets polyploid plant lineages apart from their diploid relatives. They also discovered plants that that became polyploid in their recent evolutionary past are less likely to diversify into new species and face a higher risk of extinction compared to their diploid relatives.

Journal reference

1) Recently Formed Polyploid Plants Diversify at Lower Rates

Itay Mayrose, Shing H. Zhan, Carl J. Rothfels, Karen Magnuson-Ford, Michael S. Barker, Loren H. Rieseberg, and Sarah P. Otto

Science 2 September 2011: 1257.Published online 18 August 2011

2) University of Arizona news