So goes the monarch caterpillars on our backyard milkweed plants. The small bushes begin to look like Charlie Brown Christmas trees as the caterpillars crawl up and down the milkweeds devouring each and just about every leaf. It is smart that the monarchs only lay a single egg on a milkweed plant and not all the eggs in one place. This way there will be enough food for the caterpillars to eat. Most butterfly species use this strategy.
Evolution played a role in this. Over the hundreds of thousands of years that butterflies evolved, those monarch butterflies that laid too many eggs on one plant died because there wasn’t sufficient food for all of them. The genes they carried to lay many eggs in one place died with them. The offspring of the “smart” adults that placed their eggs judiciously survived and passed this single egg laying gene on.
Evolution has a way of weeding out problem areas of species that help them survive. If a species can’t adapt to the changing world, it perishes. There were five species of humans all living at the same time over 200,000 years ago. We are the only ones that did not become extinct because we evolved behaviors that helped us survive unstable environments. Where will evolution takes us? Will we be able to meet the challenges of the future? Only if evolution enables our species to survive another 200,000 years will those questions be answered.