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?
• The answer is complex, but the bottom line is that an invasive plant species starts with a big advantage: its natural predators, parasites and pathogens are generally absent from its new environment. Therefore, it doesn’t need the genetic diversity which would otherwise ensure that such threats only affect a proportion of the population.
In addition, a large proportion of invasive species do not reproduce…
