The Evolutionary Arms Race

Other than the geographical impact of natural selection, one of the stronger influences on the development of a living thing’s characteristics are its own predators, as well as its own species. The butterfly’s eye-patterned wings are there for good reason, as a deterrent to predators, as well as the venomous snake and spider’s red and black stripes and spots. However, there are some characteristics caused by other animals that are far subtler.Pick a tree, any tree. Actually, pick one from the sprawling plains of the African savannah. Even better, the African acacia is a fine example. A long-term favourite of the giraffe, the African acacias that live the longest are the ones that grow the tallest. And living longer is, of course, crucial to survival, which in turn is crucial for replication and thus more taller acacia trees. So, much like the race for military power and technology between the United States and the Soviet Union during the Cold War, there is a constant arms race between the trunk of the acacia, or any tree, and the neck of the giraffe, or any grazing animal for that matter, that has been raging for hundreds of milennia. The giraffe, however, is only the very beginning of the acacia’s struggle for survival. In a dense forest, only the tallest trees will reach the light. As much as that sounds like a Chinese proverb, it isn’t and it couldn’t be truer; the demand for height is also caused by peer competition amongst trees and shrubs in crowded forestland. So why aren’t trees just ridiculously tall already then? Good question. The answer is physics; a taller tree will need deeper roots and a thicker trunk, which in turn will require more energy. A tree doesn’t need to be hundreds of feet tall, it just needs to be tall enough: a few inches higher than the giraffe’s reach will suffice. If you volunteer in Costa Rica, you might even be lucky enough to visit the Galapagos and get a chance to see many clusters of evolutionary arms races at once.Be it the giraffe and the acacia, the speeds of the cheetah and the gazelle,  or anything other livings things that you want to witness an arms race in, there are many cheap and easy ways to get across the world and start seeing these things for yourselves. For instance, you could volunteer in Guatemala like in the advert I saw today.