Avocados and Osage Oranges only make sense in the light of megafauna. That is because American gomphotheres (related to elephants) and ground sloths ate and dispersed those large-seeded fruits. While those megafauna went extinct around 10,000 years ago, many large-seeded plants in the Americas are still around today. If those plants once relied on those large creatures to disperse their seeds, why have they not gone they way of the dispersers? Three ecologists have gotten us one step closer to understanding why.
In a paper published in the open-access journal PLOS One, Drs. Guimarães, Galetti, and Jordano investigate the ecology of about 100 large-seeded plants that were once dispersed by megafauna. The authors conclude that many large-seeded plant species, that once relied on bygone American elephants and compadres, now rely on present-day small and medium-sized mammals such as primates, tapirs, along with pigs and cows, for seed dispersal and regeneration. They warn that the fast-paced decline of those animals in many forests today poses a serious threat for these unique plant species.
Where's a gomphothere when you need one?
Visit PLOS One for a copy of the article.
Life Science
Environment
Comments
You can send a trackback if you want (will make me happy)... ;-)
Posted by: Coturnix | April 2, 2008 1:33 PM
Very good observations here, Josh. I only wish those who stood opposed to the introduction of megafauna proxies were more aware of the critical role those now missing pieces of the system actually played, and could understand that the desire to see these proxies is not simply an impractical and impossibly romanticized vision of a new pleistocene but a desire to see the system up to its potential. Cheers. P.S....I love those osage oranges; really marvelous trees and I'd always wondered how their fruit was part of it strategy for reproduction.
Posted by: doug l | April 2, 2008 4:16 PM
As usual, the authors of this paper on fruit dispersed by "extinct megafauna" have forgotten about bears, which have a large proportion of plant matter in their diet, and would be quite capable of eating such fruit. Bears have also survived over the areas inhabited by such plants until much more recently than other megafauna.
Posted by: Christopher Taylor | April 2, 2008 6:36 PM
This is an awesome example of co-evolution just as I am a good example of how baselines shift--I was always wondering why avocado seeds were so dang big...
Posted by: Jennifer L. Jacquet | April 7, 2008 2:31 PM
I saw a seminar once, a decade ago or so, where a guy explained why he believed apples had originally involved to have their seeds dispersed primarily by bears. I can't remember the reasoning now, but it seemed sensible at the time.
Posted by: Dr. Octoploid | April 9, 2008 1:35 AM