Walkingsticks Prove Darwin Correct
Walkingsticks in a warm embrace.
Photo: © Debbie Hadley, WILD Jersey.
Charles Darwin's theory of natural selection is widely accepted by scientists and high school teachers worldwide, except maybe in those intelligent design circles. The critters that adapt best to their ecological address will outplay, outwit, and outlast the others, and maybe even evolve into a new species. It just makes sense.
But what if there's more than one way to adapt? A University of British Columbia researcher decided to delve a little deeper into Darwin's famed theory. Walkingsticks, or stick insects, are known for their convincing disguises as twigs and sticks, which keep predators from finding them among the branches where they live. Certain species of walkingsticks fit in specific ecological niches, where their colors serve them well and with vegetation they can digest.
UBC post-doctoral fellow Patrik Nosil took walkingstick eco-types out of their comfort zone, and moved them to new host plants. He protected some from predators. The walkingsticks could adapt in two ways - by changing their colors, and by developing the ability to detoxify the chemicals in the new host plant.
Walkingsticks that simply changed color took the first step toward creating a new species. But as Nosil discovered, one adaptation was not enough to cause speciation. The insects that also managed to detoxify their new host plants won the prize of passing on their genes and creating a new, improved stick insect.
Comments
Darwin was correct that character traits can change, however, even as this article says, there was never any new species created by a character trait change. Animals have the ability to adapt to their environment, not become a completely new animal. No matter how long you observe a stick bug, it will never evolve into a beetle, or dog or any other species. It has never happened before, so it just makes sense that it won’t happen in the future.
Actually, the article is talking about the creation of a new species as the result of character changes. Speciation is the evolutionary differentiation of a pre-existing species into one or more distinct species. Beetles belong to an entirely different order or insects, so of course a walkingstick would never become a beetle through a simple character trait change. However, an existing stick insect species could evolve into a new and distinct species of stick insect, through the process of natural selection. Evolution happens in tiny increments, not in major leaps.