9 Unexplained Mysteries of Evolution
Most of us who weren’t educated in a religious-based school have some idea about the main concepts surrounding evolution. Evolution is defined by the Cambridge English Dictionary as “the process by which the physical characteristics of types of creatures change over time, new types of creatures develop, and others disappear.”
Even though we were taught that it was a relatively straight path between apes and humans, the truth is that scientists and evolutionary biologists are making new discoveries about our evolutionary path all the time. Moreover, these discoveries are only raising more questions — not giving us answers.
There are a lot of unexplained mysteries that still surround the process of evolution, including several famous unanswered questions that we’re going to talk about today.
1. The Discovery of Homo Naledi
In 2015, scientists made a huge discovery when they found a cache of bones hidden deep inside a cave in South Africa. They realized that these bones didn’t match any of the other human ancestors that they had previously cataloged. When they reconstructed what Homo Naledi’s body would have looked like, they found that this race had a small brain and broad, ape-like shoulders built for climbing.
The massive trove of bones was discovered by two cave explorers, who immediately alerted a local scientist to the find. A huge expedition into the cave allowed scientists to begin putting the bones together. The mystery came when they attempted to fit this new species into the timeline of evolution. They found that there were several contradictory characteristics — like a modern human pelvis combined with curved fingers for climbing trees — that made classification difficult.
Scientists are still not sure whether Homo Naledi lived at the same time as Homo Sapiens.
2. Tuskless Elephants
It may shock you to learn that not all elephants alive today were born with tusks. In some areas of Africa, elephants are increasingly being born without tusks, which many scientists believe is an evolutionary response to poaching.
For centuries, poachers have been targeting the elephants with the best ivory, which has fundamentally altered the elephants’ gene pool. Almost a third of the elephant population of Africa has been slaughtered in the last 10 years to meet the unquenchable global desire for ivory.
Now, there are some areas of Africa, like the Addo Elephant National Park of South Africa, where 98 percent of female elephants are born without tusks. Although this survival mechanism will protect elephants from poachers, scientists are worried about what this means for the future of the species.
3. Giant Pandas
Although these gigantic adorable creatures are some of the most popular zoo residents in the world, many scientists are still confused about the evolutionary purpose of the giant panda. Pandas look like bears. As such, they have a heavy body and claws but only eat bamboo. So, they don’t use their size or girth for hunting.
Scientists have only found a few fossils that could potentially be from giant panda ancestors, so they aren’t exactly sure how their lineage developed. Teeth found in 2012 in Spain led scientists to believe that the giant panda genus originated in Europe before they migrated to Asia. However, they still aren’t sure whether it was a direct ancestor of the giant panda we know today or a sister species that are now completely extinct.
Another mystery of evolution that has been troubling scientists in the past few years is the sudden appearance of parthenogenesis in snakes.
Parthenogenesis is a natural form of asexual reproduction, which allows the growth of embryos without fertilization. It’s a common reproductive method in plants, as well as some species of invertebrates and vertebrates. Snakes can experience parthenogenesis but have usually used the traditional method of fertilization to produce their eggs.
Parthenogenesis is considered an evolutionary stopgap measure to prevent a species from dying out. However, scientists have been discovering that some female snakes in the wild, including cottonmouths and pit vipers, are turning to parthenogenesis while there are still viable males in the area. These parthenogenic births produced smaller litters than normal and it’s still unknown whether or not the parthenogenic offspring can still reproduce regularly.
5. The Evolution of Snakes
Another evolutionary mystery that has surrounded the snake for a long time is why they currently exist in the form that we know today.
In 1997, a fossil was discovered that showed a snake with vestigial hind legs, showing just one step in the snake’s evolution from lizards. Although scientists have begun to piece together the lineage of the modern snake, they still aren’t sure why they lost their legs in the first place. It’s been very difficult to discover viable snake fossils, partially because their skeleton is so delicate.
Currently, the working theory is that these two-legged snakes whose fossil was discovered in 1997 were descended from an as-yet-undiscovered lizard ancestor. This ancestor would have used the legs for burrowing.
One of the most controversial fossils ever discovered was Archaeopteryx, a creature that links dinosaurs to the birds that we know, love, and eat today. It serves as a transitional ancestor because it carries several of the same characteristics as predatory dinosaurs and had feathers and wings like modern birds. In this fossil, we can see how feathers may have evolved because of the need for insulation, making flight a secondary usage.
Scientists are still confused as to what Archaeopteryx tells them about flight. So, the debate still rages about whether flight started from the tops of trees and downward or from the ground up. Although Archaeopteryx would have been capable of flight, its flat sternum would not have supported the weight of extensive networks of flight muscles, which means that it likely was more of a glider.
7. Humpback Whale Songs
One of the most beautiful and mysterious aspects of marine life is the song of the humpback whale. Marine biologists have been studying it for years and are still unable to understand the nuances of each unique song and what their exact purpose is.
Humpback whale songs are most frequently heard during breeding season. Therefore, it was originally thought that male humpbacks used the song as a form of courtship performance. That was until research showed that female whales actually didn’t approach the males that were singing.
The current hypothesis is that male humpbacks use these sounds to form alliances and claim their territory during mating season. Researchers have found that whales from the same group share similar themes in their personal songs, but each whale has their own unique vocalizations.
8. The Development of Larger Brains in Humans
One of the biggest evolutionary leaps in human history was the move from a smaller, ape-like brain to the larger brains that we all have today. In the six to eight million years that we’ve been evolving, our brains have gotten three times larger. Also, our brain uses more energy and resources than any other part of our body.
In 1995, a study published in the UK posited a theory that our brains got bigger because our bodies began diverting energy from elsewhere — although there’s still a lot of debate about how and why this trade-off occurred.
Currently, the leading theory is that our bodies became less muscular as our brains evolved to the larger size that they are now. Although there are some humans who are extremely muscular, just one look at a modern ape shows that we as a species would absolutely lose a battle of the brawn.
9. Are We Still Evolving?
Although it’s tempting to think of ourselves as the pinnacle of evolution, our species is evolving all the time. There are several scientists who have posited some theories on where we may be going next. Their answers are both exciting and fascinating.
Sarah Tishkoff, a geneticist from the University of Pennsylvania, believes that in 10,000 years, genetic differences around the world will dwindle. Since our culture is evolving more rapidly than our genes, we’ll remain the only human species.
Another belief is that because we’re now involved in the manipulation of our own genes, we’ll be able to shape our own evolution. As such, we can get rid of a good number of the most harmful diseases that affect our vulnerable bodies, leading to a stronger, more age-resistant race.