Ants have turned the Cape of Good Hope into their own giant garden

Illustration for article titled Ants have turned the Cape of Good Hope into their own giant garden

The region of South Africa around the Cape of Good Hope has some of the highest biodiversity in the world. Exactly why that is has puzzled scientists... until now. It's actually all because ants are secret horticultural geniuses.


In another remarkable example of evolutionary symbiosis, many plant species in the Cape region have developed fleshy structures on their seeds known as elaiosome. The elaiosome exists pretty much for one reason and one reason only — to make the seed attractive to ants. And because the ants don't want to eat the tasty elaiosome right then nd there, they end up taking the seeds back home with them. This greatly expands the possible places these seeds can end up in the next generation.

It's a phenomenon known as myrmecochory — not the catchiest of names, I'll admit — and it appears a huge part of the region's biodiversity can be traced back to ants carrying away seeds. Even better, ant poop plays a highly crucial role in this process, as Professor Jonathan Majer of Australia's Curtin University explained to the BBC:

"Ants pick up the seed often by grabbing the elaiosome, take it back to their nest and feed on it. They often discard the remaining seed, which is not killed, either in the nest or in the soil around the nest...and this dispersal is known as myrmecochory. Sometimes the ant nest is richer in nutrients because of faecal material and waste so it may end up in a nutrient enriched area, which is better for the process of germination. Ants spread seeds over short dispersal distances [causing] low gene flow. Because the genes don't flow you're likely to get higher speciation. Secondly because the seed has been buried, put into a microsite in the ground, it has a higher population fitness and a lower extinction rate."

For more, check out BBC News. Image by La Chiquita on Flickr.



This is an interesting question, then, regarding the expansion of various invasive fire ant species, both in the U.S. and other countries such as Australia. Do they produce any sort of benefit as well, or is it not applicable since the plants did not evolve in conjunction with them.