When we think of man, we accept him Homo sapiens, i.e., we, the only ones who measure as human. However, if you hold that view, you may be surprised to know that it is not true at all. We are not the only ones that have evolved from tree-dwelling animals to bipedal social creatures. However, we are the only ones left from that group, the only ones who survived. Not long ago, if you assume that 300,000 years ago not that long, there were at least 8 different types of people that were on this white blue dot that we call our home, planet earth.
In an interview with Living Science, evolutionary biologist Nick Longrich from the University of Bath in the United Kingdom noted that it was strange that we now have only one human species. Before our species came, there was a wide variety of human species living on Earth.
Estimating how many human species there were on the planet at one time is not an easy task. We only have fossil remains to keep track of numbers and fossil discovery doesn’t end there. Now and then, new fossils are found that do not correspond to any of the previously known human species.
We come under the genus Homo, and Sapiens is our genre. Gender is defined as when two members of the group can successfully conceive children, but similar members do not. Some biologists agree and say that we should classify sex simply based on anatomical features. Other schools suggest that DNA should be the only one that should name species.
Once there were other species within this genus, Homo. John Stuart, an evolutionary palaeoecologist, says the different number will be based on the scientist you talk to. There is a school of thought that even suggests that Homo erectus is actually made up of a number of different species, including Homo georgicus and Homo ergaster.
It is extremely difficult to identify what people would measure as a different species due to the lack of DNA sequences. Denisovans and Neanderthals are recognized as human species but have never been put in order. But some argue that Neanderthals are just our ancestors and not a separate species.
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Therefore, some experts believe that it is impossible to classify from an evolutionary point of view when it comes to humans. With different categories depending on the meaning of the word gender itself, it is difficult to determine how many human species there were. Some move back to the hominin family. It was the hominin group where our shared ancestor separated from Chimpanzee.
Considering our last common ancestor separated 6 million to 7 million years ago, it must have been a very diverse group then. According to the Smithsonian, 21 human species are known. But other papers list only 10-12 species as humans. Some listings do not include Denisovans while others do not Homo naledi, a human species the size of a hobbit found in Indonesian caves. This is probably because they look more like chimpanzees than we do. But Stuart describes it as, “You can’t go back 5 million years and expect them to be like us,” and he argues that they are early humans.
In conclusion, although the exact number is not known for certain, the human species were much more diverse than most estimated.