Somewhere in Germany, a laboratory researcher is marveled. Could this finding be authentic? It seems to be one of those findings scientists tagged impossible. But this is a raw tangible fact staring us in the face; this girl is the offspring of two species that are completely different. As soon as the awe-struck researchers deciphered the true meaning of this discovery, it dawned on them that they could only go forward from there on after. The strange girl as well as our abandoned history would change forever.
The Beginning
The probability that evidence of this would be found was zero to none… At least, that’s how it appeared to the scientists. In a Siberian cave, researchers found a small piece of bone. At first, they couldn’t tell that it was a hominin bone – This is a term that embodies all human species. However, not long after, a beautiful story began to take shape.
The Brave Finder and The Exciting Finding
Despite having been lost for decades, the bone was eventually discovered by a brave researcher named Viviane Slon. She took her bravery a step further by attempting to extract some DNA from the bone. Her subsequent findings have upturned years of research. We’re now armed with newly uncovered information on how human beings of old survived on earth. But what made the bone significant?
An Addition to The History Books
We’re well aware that before and even with modern humans presently, various species occupied the earth. However, this specific find was the pioneering discovery of a direct hybrid. It was a momentous discovery that would line the pages of history. Hence, it’s no surprise that the scientists greeted it with excitement.
The Story of The Bone Fragment
This bone fragment has an extraordinary story behind it, one about the human species. Presently, all humans are of one species; homo sapiens. The first appearance was about 200,000 to 300,000 years back. However, mavins who study pre-recorded times and happenings know that it wasn’t always like that.
The first known humans
The Australopithecines were the earliest humans known to us. These embodied various species that were bipedal. Research says that these hominins which were distant relatives of the homo sapiens were first found more than four million years back in Africa. Surely, as expected, their appearance would have differed from ours greatly.
Evolving to higher animals
Researchers believe that the next evolution saw the emergence of the different Homo species. Initially, their legs evolved to be longer, better suited for walking and running. Subsequently, their brains grew and these evolutionary changes may have brought about behavioral changes. This is because these early humans took to hunting and developed a more carnivorous appetite.
The first appearance of “Modern Man”
About 700,000 years back, the emergence of the species called the Homo heidelbergensis was recorded in Eurasia and Africa. According to researchers, these species looked more like modern-day man, building the evolutionary foundation for how their succeeding species would look. They also behaved differently from the preceding species.
First race of “Modern Man” gone
It seems that the Homo heidelbergensis exhibited more intelligence than their predecessors. some of them used tools more sophisticated than the usual to do things like improving their hunting. Some scientists are of the belief that individuals from these species may have formed teams to hunt down bigger animals, showing a level of a social bond. However, regardless of the many strengths of this species, it still went into extinction.
Proof of life found
Keep in mind though that the Homo heidelbergensis didn’t go into extinction without leaving proof of their existence. Quite contrary to that, about 390,000 years back, sometime around the Middle Pleistocene era, various species broke out from this single ancestor. These offshoots would eventually give birth to the modern human species.
The German Discovery
The story of the human race is replete with different interesting evolutionary stories. It is believed that some of the hominin species may have lived amongst themselves through the centuries. And their coexistence was not held together by mere tolerance of the other. Scientists, over time, have been aware that some level of interbreeding occurred between these various groups of hominins. But there was no proof of this theory till the German discovery.
Theories of Interbreeding
It is retorted that individuals of different species cannot interbreed successfully, this notion is not remotely close to tangible facts. In an article in 2018, Forbes‘ Michael Marshall pointed out that although the offspring of a donkey and horse, the mule, is always infertile, the results of such cross-breeding amongst other animals may differ.
The Dynamics of DNA and Chromosomes
As it appears, it all comes down to the DNA. The mule is the outcome of a breeding relationship between a horse with 64 chromosomes and a donkey with 62. Therefore, the offspring of this pairing ends up having an odd number of 63 chromosomes. Of course, there are consequences of this naturally. Seeing as the dynamics of sexual reproduction require a sperm and an egg to contain half of each animal’s chromosomes, an odd number means the animal’s genetic code is defective. The result is that it cannot reproduce.
Evidence of Truth in The Theories
However, certain primates like the orangutans and the gorillas have similar chromosome numbers. Some scientists have postulated that it might be more feasible for them to birth healthy offspring. There’s even proof that at different times in the past, some form of interbreeding has occurred between bonobos and chimpanzees.
The Liger Explained
This theory may even offer an explanation as to why some wild felines can interbreed successfully. The highly-praised liger isn’t a naturally occurring species since lions and tigers live in natural habitats that are far apart. However, many zoos in the world have this animal, which grows bigger than both the tiger and the lion in adulthood. Ligers can also reproduce.
Interbreeding amongst Hominins?
More importantly, it is believed that early humans had the same chromosome count. This implies that interbreeding was possible among the various species. According to experts, Homo sapiens and Homo neanderthal mated quite shortly after the former migrated from Africa into different parts of the world.
Old Hominins in Modern Day Asia and Europe
This explains why up to 2 percent of Neanderthal DNA can be found in a larger number of Asians and Europeans. Possibly, your own genetic test has shown this? However, it wasn’t just the Homo neanderthal that the Homo sapiens mated with. It would seem that they also copulated with another hominin group called the Denisovans.
The Latest Hominin Finding
Denisova
In excitement and satisfaction with their huge discovery, the scientists named the species ‘Denisova‘ to honor the cave where they found the specimens. However, apart from the information uncovered from the DNA, not much was known about this group of humans. In 2012, they stumbled upon another bone fragment in the same site in Siberia.
An Accidental Discovery
Initially, the ordinary-looking fragment was kept with the numerous fossils that were excavated from the cave. Nothing else was uncovered till a number of years had passed and Samantha Brown from the University of Oxford studied them closely. Acting on instructions to catalog the artifacts, Brown studied the bone’s proteins. It dawned on her that it belonged to an early human.
Beyond Expectations
After this discovery, paleogeneticist, Slon received the bone. In a bid to discover more about this unknown species, she also commenced investigations on the DNA in the fragment. Her findings were more than expected.
A teenager?
Initially, the bone seemed not to be of great significance. It was merely an inch long. It seems to have belonged to a female teenager aged about 13 years. She is believed to have died about 90,000 years back when this little part of the Altai Mountains was occupied by the Denisovans.
The Big Surprise
However, when Slon studied the DNA in the mitochondria of the fragment, she was stunned at what she saw. It is common knowledge to any genetics aficionado that this cell structure houses material that is inherited from a mother only. This particular case revealed that the teenager was a descendant of a female Neanderthal.
Two for One
Slon, while speaking to National Geographic in 2018 said that it was quite exciting already and became more so when they began to study the nuclear DNA. Genetic knowledge revealed that the fragment understudy was a component of both the male and female ancestry, thus, the researchers could learn about the ancient child’s father.
A possible mistake
According to Slon, it was at that moment that they knew there was something odd about the bone. The astonishment of the results was so great that she thought at first that she was mistaken. Had she messed with the data unwittingly? Could the sample have been tampered with in the laboratory?
Confirmation
Ultimately, Slon saw that she didn’t make any mistakes. While the teenage girl’s mother had the DNA of a Neanderthal, the analysis showed that her father was a Denisovan. That was not the end. As she ran her analysis on the bone fragment, the paleogeneticist found that there were astounding variations in the girl’s general genetic makeup.
The Science of the Genetics
In plain English, you may ask. This is related to a concept called heterozygosity. Basically, if your parents were close relatives, say like second cousins, your genes would have very little heterozygosity. But if your parents were from different species, your genes would show crazy-high levels. Get it?
The Holy Grail of Evolution
Now, the latter was the case with the bone stumbled on in the Denisova cave. In a discussion with National Geographic, Richard E. Green, a computational biologist offered more insight into ancient DNA. “It’s heterozygous out the wazoo. That’s really what nails it” Slon had uncovered one of the treasure troves of human evolution – an offspring born from the interbreeding of two species, the very first generation.
Slon’s comments
In 2018, while talking to a London newspaper, the Evening Standard, Slon said that prior studies had revealed that Denisovans and Neanderthals must have produced hybrid offspring together. She also added that they never expected to run into such luck as finding a real offspring of the two species. David Reich, a Harvard University geneticist concurred.
Excitement
Speaking to National Geographic, Reich said that a finding like that was remarkable. He went on to say that it didn’t seem possible to actually catch the phenomenon in action – a real human being that’s the actual first-generation offspring of a hybrid. The finding was so unexpected that it gave way to many questions on how common it was to interbreed.
Child Born of two Species
While discussing with the Evening Standard, Svante Pääbo from the Max Planck Institute expressed his excitement. He said that finding the Denisovan/Neanderthal child in the midst of the few sequenced genomes belonging to ancient humans was brilliant. He further said that Denisovans and Neanderthals may not have been opportune to meet many times. However, they must have copulated considerably often than we prior believed.
Doors of new discovery
While there is a possibility that there was more to the discovery than sheer luck, scientists are trying to come up with other theories. One of them is that these two hominin groups lived together and interbred regularly. If there’s truth in this theory, then everything we thought we knew about the ancient world is about to be overturned completely.
Disclaimer: The events of this story are entirely fictional and are products of the author’s imagination. Images included are meant for illustration purposes only. Any resemblance to actual events, places or persons, living or dead, are entirely coincidental.