More info about this myth
People often think that genetic mutations are a bad thing, but it is worth remembering that mutations are essential for evolution to happen. Without these changes to DNA all life on Earth would be still be stuck in the unicellular phase it first appeared in around 3.7 billion years ago!
From the first mutation that led to a second single celled organism, to the genetic variation that resulted in multicellular life, to the changes in DNA that produced our own species, each mutation (both good and bad) has been part of the story of life on Earth. Of course, some genetic mutations, often called ‘variants’, can cause problems, but many have generated incredible adaptations.
One example of a beneficial genetic variation is people with a mutation in the LRP5 gene that amplifies this gene’s function. This gene, also called the ‘lipoprotein receptor-related protein 5’ gene have increased bone density, meaning their bones are particularly strong and unlikely to break. (This condition is the inverse of the mutation in the same gene which impairs the function of the gene, which causes osteoporosis.) Not only are people with this genetic variant much less likely to break bones, but also show no signs of the normal skeletal degeneration. Researchers first discovered this condition when someone with the genetic variant walked away from a serious car accident with no broken bones.
Without any genetic mutations in the human species, we would all look the same with no variation in height, hair texture, eye color or skin tone. None of us could digest lactose, we wouldn’t live as long, and there would be no variation on which diseases people can withstand. If there was no variation, we as a species would be very susceptible to the same illnesses, there would be no difference in people’s sporting or musical abilities, everyone would like the exact same foods and so on. Imagine how boring life would be with no variation!
There are also countless example of beneficial mutations in the animal kingdom. One type of bird, called Rüppell’s griffon vulture, has evolved to have hemoglobin that is so successful at absorbing oxygen at low pressures that it can fly at the highest known height of any species, over 7 miles (11.2 kilometers) up in the air! There are frogs that can survive sub-zero temperatures without freezing, giraffes have incredibly high blood pressure to prevent them from passing out, caterpillars that camouflage to look like bird poop, and woodpeckers have a tongue that wraps around its brain which helps protect it when it is pecking trees with its beak. Each of these adaptations are the result of a series of genetic mutations that have been selected for during the process of evolution.
To hear more about some other incredible mutations, you may like to listen to Episode 5 of the Nice Genes! podcast. On this episode you will hear from one of the researchers involved in the research about tuskless elephants, jellyfish that never die, and some amazing adaptation in humans. Find the episode here.
Educators: For an additional free resource to use with your students you may like to investigate the ‘Learn-a-long’ activity on the podcast page. This educational resource was created by our Geneskool team for use in the classroom as you listen along to the episode, to help deepen engagement with the content of the episode. You can find Learn-a-long sheets for each of our podcast episodes, not just this one!