We've all daydreamed about having superpowers, and the ways they could improve our lives. "If I had super speed I could go anywhere in minutes," "if I could fly I could finally clean my roof gutters," etc. But that's frequently the opposite of how things work in real life: Many creatures have gained an evolutionary advantage by shedding a superpower.
Penguins Lost Flight
The South Pole: home to some of the most fierce predators on Earth. Monstrous polar bears Egg-snatching birds, leopard seals, and of course the most scary of them all: cute waddling penguins.
Penguins used to have the superpower of flight. But flight is best used from getting from one point to another quickly. The South Pole is all ice (spoiler alert). The Eskimos may have 50 different words for snow, but it's really all the same. There's no "point B" to fly to at the bottom of the Earth. Unlike these barren snowlands, the seas were teeming with life, much of it food for tuxedo-clad birds. So the penguins whose wings were thicker and more suited to swimming than flying survived over their lighter-winged, flighted brothers.
Mammals Lost the Ability to Feel No Pain
The central nervous system is amazing. It allows you to think, move and type out witty rejoinders on erotic superhero fan fiction messageboards (it's not just us, right?). But one aspect of the nervous system that has puzzled scientists for centuries is why it decides to send us agonizing signals of pain.
As it turns out, the ability to feel pain is an evolved trait: Apparently, just sending a painless "red flag" to the brain is not enough for survival. In fact, a few hundred humans lack the ability to feel pain, and they live shorter lives because of it.
Mammals Lost the Ability to Regenerate Limbs
Regenerating limbs seems like a useful trait, especially for people who work in a deli. But, unlike many species of reptile, mammals cannot grow back a sliced-off finger. Why some animals can regenerate limbs yet other animals (such as humans) cannot is a subject of much debate among scientists.
One popular theory is that mammals are more prone to cancer than reptiles: The human body limits cell production, because uncontrolled cell populations are much more susceptible to the Big C. It is this same inhibition of cell growth that prevents a severed limb from being replaced with a mass of new cells.
Fish Lost Breathing Underwater to Become Primates
Way back in the evolutionary chain, primates used to share a superpower with everybody's favorite superhero punchline, Aquaman. But the ability to breathe underwater eventually proved to be more trouble than it was worth. Before they were swinging through trees and climbing Empire State Buildings, they had to drag themselves out of the oceans. With too much competition for aquatic food, tetrapods developed legs and started flopping onto beaches. They developed gills and lungs (Acanthostega), and eventually lost those gills in exchange for more lung power. Because no animal really needs gills and lungs. Except, of course, lungfish.
Some Plants Gave up the Ability to Get Energy from the Sun
Photosynthesis is one of the most unheralded superpowers possessed by any modern creature. It provides "food" for plants, and thereby becomes the most primary building block of entire ecosystems. We just spent 15 minutes making and eating a sandwich, whereas if we had photosynthetic superpowers, we could've just raised our window blinds.
Still, as amazing as photosynthesis is, there are members of the plant kingdom that have found it to be an inhibition to their survival. Naturally, converting sunlight into food takes energy, and there are parasitic plants that have found that this energy could better be used spreading out all over a host. Myco-heterophytes attach themselves to trees, the trees use photosynthesis and transfer the nutrients to the parasitic plant, which uses the saved energy to cover even more of the tree.
Fish Lost Armor-Plated Skin
We imagine that, in prehistoric times, being in the ocean without some sort of armor coating would be a death sentence. This is probably why a sub-section of fish known as ostracoderms were covered in armor-plated skin. Yet, soon, the slow-moving ostracoderms found themselves unable to escape predators, whereas the ones with lighter or no armor could swim away. This gave birth to what we now know as most modern-day fish, which have strong-looking (but ultimately plious) scales and can swim away from a predator (or a net, or a spear, or a stick of dynamite) almost instantaneously.
Sea Worms Lost a Shared Skeleton
One unique superpower we haven't seen covered much in comics is a shared skeleton. Hundreds of millions of years ago, an animal called the graptolite possessed the ability to form like Voltron. Graptolites would share one long nerve cord and would function together as an incredible mass of creatures. Eventually, the permanence of connecting one's skeleton to a network became a hindrance, because an even more useful trait is the ability to move freely. This prompted graptolites to evolve and split off into single, separate animals.
Every Multi-Cellular Organism Lost Immortality
No one knows for sure how life evolved from single-cell organisms into the complex, bad-science-article-reading creatures we are today. But one popular theory postulates that all single-celled organisms were once immortal. Certainly, even today, there are creatures which display traits of immortality.
As the theory goes, these first single-celled organisms encountered a problem with immortality: overpopulation. There were simply too many of them to facilitate the conditions for reproduction to occur (like having enough food, having space to reproduce without a million of your friends watching, etc.). Whereas the cells which had a "mortality mutation" found that their population stayed controlled enough to continue to reproduce and evolve. So, by dying off at a reasonable age, these organisms ensured there would be enough resources for future generations. Take note, Baby Boomers. (No, no, we are kidding, please stay alive until the Singularity.)