Battle for Survival May Yield the Rain Forest’s Diversity
▻http://www.nytimes.com/2014/01/03/science/battle-for-survival-may-yield-the-rain-forests-diversity.html
It’s tempting to look at all those species [of trees] living so close together as a picture of peaceful coexistence. But Phyllis D. Coley and Thomas A. Kursar, a husband-and-wife team of ecologists at the University of Utah, see them as war zones. Hordes of insects threaten the survival of plants, which respond with chemical warfare. The result, they argue, is the remarkable biodiversity we see today.
“It’s not harmonious,” Dr. Coley said. “It’s a constant battle to stay alive, to stay in the game.” Dr. Coley and Dr. Kursar outline their hypothesis in this week’s issue of Science. [...]
The tropics have thus become host to an arms race. Each species of plant is evolving defenses against its enemies, which evolve counterdefenses in turn. This arms race would explain why tropical plants have become so loaded with toxic compounds.
It might also help solve the mystery of tropical biodiversity. “We think this arms race between the herbivores and the plants might be the explanation for what maintains the diversity that we see now, and why so many plants have evolved in the first place,” Dr. Coley said.