Javier Igea at the University of Cambridge, UK, and his colleagues analysed the masses of individual seeds from more than 30,000 flowering plants. They found that the faster a plant species diversified — by splitting into different strains or species — the smaller its seeds tended to be. The size of the seed also tended to change more quickly over time in fast-evolving plants. The finding confirms that seed size can influence the way in which a plant evolves. For instance, smaller seeds can be dispersed farther, allowing small, isolated populations to grow.
Smaller seeds are also associated with shorter-lived plants, in which more rapid turnover provides more opportunity for mutations to occur.