The Last Surviving Homo Species
Homo Sapiens, the group to which all anatomically modern humans belong, stands as the last surviving species of the Homo genus, a lineage that has shaped Earth’s history for millions of years.
Source: Wikimedia
Prior to their extinction, our cousins, the Neanderthals, Denisovians, Homo floresiensis, and various other groups lived around the world, each playing a significant role in the evolution of humans on Earth.
The Achievements of the Homo Genus
While it may seem that humans have dominated the food chain and evolutionary ladder for most of Earth’s history, this couldn’t be further from the truth.
Source: Wikimedia
In light of our accomplishments, ranging from technological advancements to agriculture and animal husbandry, no other species has even come close to achieving what humans have in such a short period. However, what we often forget is that various older Homo species played a role in helping us achieve this success.
Over 30 Homo Species
All humans have played a role in the evolution of their species, and they trace their origin back to a common ancestry known as Sahelanthropus tchadensis, which is thought to have lived around six million years ago.
Source: Wikimedia
Researchers suggest that at least 20, likely more, distinct species of humans evolved from this common ancestor and went on to populate parts of the Earth.
Questions That Continue to Plague Researchers
Despite our knowledge concerning the ancient hominin groups that predate our own species, many of the discoveries have only occurred in the last century, making this a relatively new field of inquiry.
Source: Freepik
Questions that continue to plague anthropologists and archaeologists are what led to the drastic jump in human evolution and, more importantly, why some species thrived for extensive periods while others slowly dwindled and went extinct.
Unconventional Pattern of Evolution Witnessed in Humans
A new study published by researchers from the University of Cambridge attempts to tackle these questions and details an unconventional pattern witnessed in the evolution of humans.
Source: Wikimedia
The new study published in Nature Ecology & Evolution shows for the first time that competition amongst Hominins was fundamental to our evolution.
Researchers Detail Competition Between Species and How It Shaped Human Evolution
Regarding the study’s results, Dr. Laura van Holstein, a University of Cambridge biological anthropologist at Clare College, said, “We have been ignoring the way competition between species has shaped our own evolutionary tree.”
Source: Freepik
She added, “The effect of climate on hominin species is only part of the story.”
Vertebrates Form to Fill Ecological Gaps
The study explains that in other vertebrae, species generally emerge to fill ecological niches.
Source: Wikimedia
“Take Darwin’s finches: some evolved large beaks for nut-cracking, while others evolved small beaks for feeding on certain insects. When each resource niche gets filled, competition kicks in, so no new finches emerge, and extinctions take over,” said the researchers.
Comparisons Between Extinct Hominins and Other Vertebrates
Van Holstein and her colleagues used various models to show that ancient hominins evolved in a similar manner to other vertebrates, emerging when competition for resources was low. However, when they analyzed modern humans, the findings actually portray the opposite.
Source: Wikimedia
“The more species of Homo there were, the higher the rate of speciation. So when those niches got filled, something drove even more species to emerge. This is almost unparalleled in evolutionary science,” she said.
Closer to Beetles Than Other Hominins
According to researchers, the closest connection they could find was not even in another mammal but in a species of island-dwelling beetles.
Source: Wikimedia
“The patterns of evolution we see across species of Homo that led directly to modern humans are closer to those of island-dwelling beetles than other primates, or even any other mammal,” they said.
Technological Advancements and Competition Leads to Speciation
According to van Holstein, the Homo sapiens ability to implement technological advances, which led to competition for resources, “may be behind the exponential increase in the number of Homo species detected by the latest study.”
Source: Wikimedia
“Adoption of stone tools or fire, or intensive hunting techniques, are extremely flexible behaviors. A species that can harness them can quickly carve out new niches and doesn’t have to survive vast tracts of time while evolving new body plans,” she added.
The Extinction of Hominin Species
In conclusion, van Holstein suggests the new study provides valuable insight into the events that led to the extinction of various hominin species.
Source: Wikimedia
“These results show that, although it has been conventionally ignored, competition played an important role in human evolution overall. Perhaps most interestingly, in our own genus, it played a role unlike that across any other vertebrate lineage known so far,” she said.