Human-made fires are influencing the evolutionary process of some plant species' seeds, a study has shown.

Scientists found that seeds that were less rounded and coated in thicker protective hairs were more likely to survive fires used to clear scrub.

The study was carried out in an area where natural fires were very rare, allowing the researchers to analyse the impact of human activity.

The results appear in the Proceedings of the National Academy of Sciences.

"Our findings provide insights into the understanding of the evolution of seed traits in fire-prone environments and demonstrate that human-made fires can be driving evolutionary changes in plant species from ecosystems where fire does not occur naturally," the researchers wrote.

The study was carried out in an area within Chile's matorral, a Mediterranean eco-region on the nation's west coast.