Â鶹´«Ã½

Invasive species often start with just a few individuals and multiply to huge numbers across a continent, but they don’t seem to suffer from a lack of genetic diversity. Or do they? If not, why not?

John Buermeyer, Winnipeg, Canada

We pay £25 for every answer published in Â鶹´«Ã½. To answer this question – or ask a new one – email lastword@newscientist.com. Terms and conditions apply.

Please keep your answers concise and include a postal address in order to receive payment for answers, and a daytime telephone number and email address if you have one. We reserve the right to edit items for clarity and style.

Â鶹´«Ã½ reserves all rights to reuse question and answer material that has been submitted by readers in any medium or in any format.

You can also submit answers by post to: The Last Word, Â鶹´«Ã½, 110 High Holborn, London WC1V 6EU, UK.