Do you know that there are evolutionary mysteries that humanity has not yet been able to solve? Much is already known about the origin of humans and how, in general, life has evolved on planet Earth. But despite our current knowledge, there are things that still baffle scientists. From the missing links in animal evolution to the mysterious ancestors of modern humans. We bring to your attention 25 unsolved mysteries of evolution.
Living fossils
While most species have evolved substantially over the centuries, some have remained virtually unchanged over many millions of years. Known as living fossils, these creatures are invaluable to scientists as they provide an opportunity to see what life on Earth looked like in prehistoric times.
One of these creatures is the latimeria. It was believed that this fish became extinct 70 million years ago, until in 1938 in South Africa, fishermen caught such a fish, which had recently died.
If animals have evolved over the years, why don't living fossils develop or develop more slowly? Among the most popular theories are genes with a lower rate of "replacement" and habitats that do not contribute to the development of evolution.
Promotional video:
First hominid
It was believed that the first hominid species that ultimately gave rise to humans came from Africa. However, recent studies of two fossil species, Graecopithecus Freybergi, found in Greece and Bulgaria, indicate that the distant ancestors of modern humans already lived in Europe more than 7 million years ago.
The origin of bipedalism
There have been many different assumptions about what prompted our ancestors to start walking on two legs. Some researchers argue that this was due to the need to have free hands to use tools and carry food, while others argue that this was a consequence of the need to explore the area in the tall grass. The best clues to our upright posture may come from living monkeys, but no one knows for sure how far chimpanzees are in the evolutionary ladder from our last common ancestors.
Many modern primates can walk on two legs.
How the whales got into the sea
The evolutionary path of whales remains a complete mystery. Scientists do not find a definite answer how it happened that these huge intelligent warm-blooded mammals got into the sea. It is only known that this happened during a very unusual evolutionary process, since modern whales evolved from land mammals that lived in the late Paleozoic era. Scientists have yet to figure out how and why this strange evolutionary reversal occurred.
The largest mammal that is waterfowl.
How did speech come about
The discussion continues about the time, place and circumstances of the emergence of human language. Some researchers believe that ancient man began to speak as soon as his brains became large and complex enough, while other scientists tend to believe that language is a natural development of gestures and sounds used by our earlier ancestors from the genus Homo.
The sounds made by howlers express their emotional state.
People without wool
Under what circumstances and when the ancestors of modern man were left without a wool cover - this is another mystery of the evolutionary process, which biologists and geneticists are trying to solve. Perhaps this was due to a change in the environment in which the hominids lived, or simply to reduce the prevalence of external parasites that usually lived in their fur.
Our distant ancestors had a woolen cover.
Cicada life cycle
Cicadas have one of the most mysterious life cycles in the entire animal kingdom. Certain species of cicadas can live underground for up to 17 years before coming to the surface to mate. Even more confusing for biologists, some cicada species somehow synchronize their mating cycles with similar processes in other species.
A cicada that has climbed to the surface to breed.
Human brain development process
Scientists have found that relatively "recently", about 2 million years ago, the brain of our ancestors was similar in volume and complexity of organization to the brain of modern great primates. In the future, however, hominid brains began to develop rapidly, approaching their current size and structure about 160 thousand years ago. Scientists agree that a developed brain gave hominids an evolutionary advantage, but the reasons for such a rapid development of our brain are still unknown.
Comparative dimensions of the human brain and the brain of our not so distant ancestors.
First hand tools
There is no unambiguous information regarding the time of the beginning of using the tools. For decades, the earliest known stone tools have been associated with their alleged creator, who lived about two million years ago, called Homo Habilis. But thanks to new research, it became known that intelligent hominids began to use man-made tools a little earlier.
Olduvai (left) and Acheulean stone axes found at Kokiselei (Lake Turkan), Tanzania.
Eucritta
Discovered in 1998, the most important link in the evolution of vertebrates - the eucritte was a bizarre, small creature that lived in what is now Scotland about 350 million years ago. The animal possessed a strange mixture of biological characteristics, being a four-legged reptile with amphibian qualities, but no one has yet been able to identify the evolutionary descendants of the eucritta. Some experts believe it could have been one of the first true amphibians.
This is what eucritte looked like, according to scientists.
The origin of the female orgasm
It may seem a little strange, but the question "why do women have orgasms?" Was asked by scientists for a long time. Orgasms are not necessary for procreation - a woman can have an orgasm even if she is not having reproductive sex. On this issue, there are several common opinions among the scientific community. One of them suggests that orgasms are just an evolutionary rudiment. Another theory suggests that orgasms are tied to ovulation, not reproduction.
The female orgasm is mysterious in itself.
Abiogenesis
A key part of the origin of life on Earth, abiogenesis is a natural process through which life arises from non-living matter. Despite many years of extensive research and collaboration between specialists in the field of geophysics, chemistry, biology and many other scientific disciplines, scientists are still puzzling over this existential question - how did the transformation of inanimate matter into living matter happen.
This is how life looked like during its inception.
Humpback whales and their singing
Have you ever heard the song of humpback whales? They are beautiful and amazing, but scientists still do not know when, how and why this mechanism arose. Moreover, research in this area began relatively recently. So, in the spring of 2015, a completely new sound was recorded, which was made by humpback whales near Maui, one of the Hawaiian islands. The mysterious new song had such a low rhythm that it was practically not perceived by the human ear. Witnesses described the sound as "like listening to a heartbeat with a stethoscope."
This is what a humpback whale looks like.
Australopithecus sediba
The human ancestor, designated Australopithecus sediba, raises many questions. Scientists discovered his remains in 2008 in Malapa Cave, South Africa; the fossil skeletons of this species were surprisingly complete. Scientists were able to highlight the presence of primitive and progressive traits that indicate a transition to upright posture. However, the limbs indicate a previously unknown form of upright walking. The characteristic features of the genus Homo and the combination of primitive characters found earlier in other Australopithecines make it difficult to place Australopithecus sediba in the evolutionary ladder.
Australopithecus sediba, photo from the excavation.
Ancient feathered raptor
The fossilized remains of Archeopteryx were found in 1861. Shortly before this, Darwin published his revolutionary work "On the Origin of Species" and Archeopteryx has long been considered the first bird that ever lived on Earth. However, subsequent research has shown that this amazing flying animal of the late Jurassic period was more of a dinosaur than a bird, so the appearance of birds must be attributed to a less ancient past. Some experts even argue that Archeopteryx may have turned out to be a dead-end branch of evolution.
Archeopteryx fossils.
Longevity
It is known that some animals, such as large turtles, live very long lives. The Seychelles giant tortoise named Jonathan is the oldest living land animal in the world. In 2017, he turned 186 years old. Some researchers note that long lifespan is usually associated with slowed metabolism, but the exact reasons for biological longevity are still controversial. Moreover, a slow metabolism may be just one of a variety of reasons why some species live significantly longer than others. The rest of the reasons for longevity, scientists have yet to find out.
A long-lived turtle from the Seychelles.
The end of the evolutionary path of man
There is an ongoing debate about whether the development of humans as a species continues or not. Thus, the famous naturalist David Attenborough is inclined to believe that man, as a species, has stopped in his biological development, since now we can preserve all representatives of our species, even those that otherwise would not have been able to pass Darwinian natural selection. According to another point of view, the evolution of man is still going on, but it is simply a transition to another qualitative form.
Human evolution now continues not so much physically as mentally.
Where did the snakes' legs disappear?
Under what circumstances the ancestors of modern snakes lost their limbs during evolution is a mystery shrouded in darkness. For a long time, it was believed that snakes gradually lost their limbs, adapting to life at sea, but a new CT scan of prehistoric snake fossils showed that snakes lost their limbs in the process of adapting to burrows. But when and what conditions forced the ancient lizards to seek refuge in narrow burrows - this remains unknown.
Some snakes have rudimentary leg remains.
Yeti or Bigfoot
For centuries, Bigfoot legends exist in different forms. He even got on film in the 20th century, but that picture did not clarify, but only generated new controversy. Evolutionary experts acknowledge that there is little chance of encountering previously unknown hominid species that may live in some remote areas of the Earth. In fact, various kinds of hominids have coexisted with our ancestors for almost all of the time, and our family tree may surprise us even today. So, in 2003 in Indonesia, a skeleton of the species Flores man was discovered, called the "hobbit" for its small height.
The most mysterious "relative" of modern man.
Prehistoric migrations
It is known for certain that human ancestors made several very large migrations stretched over thousands of years in time. Homo Erectus made the first big trip from Africa and to East Asia 1.8 million years ago. About a million years later, the predecessors of the Neanderthals appeared in Europe, and 125 thousand years ago, Homo Sapiens settled in the areas of the modern Middle East. Climate change and overpopulation are some of the most common hypothetical reasons that caused our ancestors to constantly migrate, but we will probably never know the true motives for these movements.
Migration map of human ancestors.
Parthenogenesis
Also known as virgin birth, parthenogenesis is a natural form of asexual reproduction and is seen in individual plants, invertebrates, and vertebrates. It is theorized that the purpose of this rare evolutionary trait was to ensure that the species evolved even in the absence of dominant alpha males. New research has revealed parthenogenesis in male snakes, which will definitely force science to reconsider its attitude to this issue.
A snake next to its future offspring.
Giant panda
A symbol of conservatism and one of the most popular bear species in the world, the giant panda has puzzled evolutionary scientists for years. These cute bears touch everyone with their vegetarian diets, a seeming lack of interest in sex and a tendency to spend most of their time sitting, eating and defecating (about 40 times a day). How this animal, so poorly adapted for survival, has overcome tens of thousands of years of evolution, remains unclear.
Panda, very cute, but not at all adapted to life in the wild.
Elephants without tusks
Scientists were surprised to find that more and more African elephants are being born without tusks. It is believed that the cause of this bizarre phenomenon is massive poaching for the sake of elephant tusks, which is destroying wild populations of African elephants. Without tusks, elephants can protect themselves from poaching, but it is unclear how new generations of elephants will adapt to life, as these giant mammals use their tusks to dig for food and water, for self-defense, during mating games and many other occasions.
Scientists do not know how elephants managed to influence the presence of tusks in their offspring.
Denisovsky man
The scientific community was shocked when a fragment of a finger bone discovered in 2010 revealed the existence of a group of ancient people that no one had seen before - the Denisovans. Since then, only a few small fragments of bones of this species have been found, so this mysterious hominid remains largely unknown to us. However, we do know that Denisovans are anatomically related to modern people, since Denisovans DNA has been found in some modern living people, mainly Aborigines in Australia and Oceania.
One of the fragments of the skeleton of a Denisovan man.
Star man
Denisovans are just one of the hominid species that has confused the minds of evolutionary experts around the world. In 2013, the skeletons of another mysterious hominid family were found in a cave in South Africa. Even after extensive research, scientists were unsure how exactly this species, now known as Homo Naledi, fits into the pattern of human evolution, as the fossils show a strange combination of characteristics found in several different species, including Australopithecus, early Homo Habilis, Neanderthals and even modern people.
Fossil remains of the species Homo Naledi.
Evolution will surely present to humanity many more interesting discoveries, in particular about its own origin, about the origin and development of life on Earth, and maybe outside the Earth. It remains only to follow the progress in this area and wonder at the mechanisms of evolution that continue to manifest themselves in the animal and plant world, contributing to the adaptation of living organisms to new environmental conditions.
Nikita Linnik