Perhaps the most starling confirmation of evolution comes from vestigial relics, those evolutionary remnants that are left behind as a species evolves.
The first example I became aware of as a (former) creationist, was the hind legs of Baleen whales. These evolutionary relics are stunted, redundant left-overs from the days when the remote ancestor of modern whales once walked on shore. If God created great whales a mere six thousand years ago, as described by Genesis, why did He give them legs?
By the time that an animal had reached, after numberless generations, the deepest recesses, disuse will on this view have more or less perfectly obliterated its eyes, and natural selection will often have affected other changes, such as an increase in the length of antennae or palpi, as compensation for blindness.
Charles Darwin, Origin of Species (1859)
Creationists argue that the cave fish is an example of devolution and represents an example of how any supposed “evolution” is nothing more than a dysfunctional mutation, trending toward simpler forms rather than beneficial improvements. On the surface, it seems like creationists may have a valid point, but rather than devolving, the blind cave fish has progressively evolved a far better olfactory sense, with taste buds spread all over its head, along with increased sensitivity in its lateral lines, allowing it to detect minute pressure changes. All of this is a marked improvement for a species that lives in the pitch black environment of a cave and a good trade-off for a pair of useless eyes in a world of darkness. From our, anthropomorphic perspective, sight is the primary sense, the most dominant sense we have, so it is only natural its loss would, to us, seem a step backwards, but nothing could be further from the truth. The heightened senses of the blind cave fish are a brilliant adaptation to a hostile and unforgiving environment.
When it comes to mankind, the list of vestigial relics embedded in our bodies is nothing short of humbling.
- Although we can make vitamin D naturally, we are unable to make vitamin C like other mammals (dogs, cats, horses, etc), but not because God decided scurvy would be a good thing and created us without this ability. Genetic studies reveal 70-80 million years ago, this trait was switched off by a faulty gene that has been passed down to all succeeding generations. Our natural diet, so rich in fruits, meant this wasn’t an issue until explorers started sailing around the world and sailors found their teeth falling out.
- Roughly a hundred million years ago, our ancestors had jaws that suited “wisdom teeth,” but, since then, they’ve been nothing but a pain, crammed into too small an area. If God created Adam and Eve a mere six thousand years ago with wisdom teeth, it certainly wasn’t a wise design choice.
- Although appendicitis is a relatively modern problem and there is some emerging evidence that the appendix assists the lymphatic system in fighting bacteria and helps gut biota, there’s no doubt the appendix is a relic of our distant ancestor’s cellulose rich diets. Any benefit to our gut represents the emergence of a secondary function. In mankind, the appendix is redundant and its removal is barely noticeable at a biological level.
- The plantaris muscle is rather embarrassing for creationists. It’s a thin, short, redundant muscle attaching to the heel that serves no purpose and is absent in 7-10% of the population. Its original function, and indeed its function in other primates, is to allow the foot to grasp objects like a hand, a trait lost millions of years before homo sapiens arose as a distinct species.
- In our arms, the palmaris tendon is equally embarrassing. It too is only present in roughly 80% of the population. As a tendon, it does not provide any beneficial function and can be removed and used in tendon grafts elsewhere in the body without reducing any functionality in the hand. Its original purpose, and its purpose in other mammals, is to extend and retract claws. And you thought Wolverine was pure fiction.
- Plica semilunaris is a fancy name for the small fold of skin in the corner of the eye. Like something out of a low-budget horror flick, it is colloquially called the third eyelid. In mammals it is largely redundant although it can be seen quite clearly in use in cats. In birds, reptiles and fish it provides an additional layer of protection for the eye.
- Can you wiggle your ears? Not everyone can, but if you are one of those so blessed, it’s not because Adam was formed with the ability to perform cool party tricks but rather because our ancient ancestors used these muscles to locate motion by sound, a trait still seen in primates today, but more clearly evident in cats and dogs.
- There are probably plenty of occasions in life where you’re glad your sense of smell isn’t as good as a dogs, but, surprisingly, you have the equipment in place, it just doesn’t work properly. When we look at the vomeronasal organ, it is quite large in humans but the genes coding for its development are at least partially defective. We can smell OK, I guess, but we don’t really have anything to compare it against, except to realise that for animals like dogs and cats, a sense of smell is more effective than either sight or hearing! Our VNO (as it is casually known in scientific circles) is still quite effective, though, allowing the unconscious awareness of our biological kin by smell alone, but it’s still not a patch on other animals.
There are other relics of our evolutionary past, but these are the one’s that catch my evolved eye (with its meaningless blind spot, something not shared by other animals).
If life were a computer, evolution wouldn’t furnish us with new programs, just lots and lots of upgrades and patches as the legacy system continues to contort and mature. The old code can be modified, rewritten or neglected, but never properly removed.
These relics we share with numerous other species are living fossil records of our evolutionary past, written into the very fabric of our bodies.
If you enjoyed this post, check out the post on creationism