March 30, 2020
Not surprisingly, de novo mutations are quite rare in the real world – but even rare things can happen if the population is large enough.
When it comes to the evolution of herbicide resistance, there are two biological pathways. The first is simply natural selection where a small number of the population can withstand a particular stress (e.g. herbicide), they set seed and eventually their progeny are the majority, and they generally thrive. Resistant alleles may prolificate at the site of selection (i.e. due to frequent and regular use of a particular herbicide at that site) or they might be imported from another site of selection as seed or pollen.
The second is ‘de novo mutations’ where the parent plants are both susceptible to the herbicide but a spontaneous mutation in the genes of the progeny renders it (and its progeny) resistant. Resistance that arises this way is very rare and often comes with a ‘fitness penalty’.Read More