Human origins remain unclear given studies of known fossils, concludes a new Science review. Today, our last common ancestor with the apes remains unknown as debate rages on for paleoanthropologists.
“The evolutionary history of apes and humans is largely incomplete,” states the review.
The study’s lead author, Sergio Almécija, a senior research scientist in the American Museum of Natural History’s Division of Anthropology, says there’s no agreement.
“When you look at the narrative for hominin origins, it’s just a big mess—there’s no consensus whatsoever,” said Almécija. “People are working under completely different paradigms, and that’s something that I don’t see happening in other fields of science.”
Recommended: Meet Australopithecus anamensis, one of humankind’s oldest ancestors
The Core of the Human Origins Problem
Between about 9.3 million and 6.5 million years ago, it is believed humans diverged from the chimpanzee lineage. Today, chimpanzees and bonobos are our closest living relatives, sharing 99% of our DNA. That’s absolutely fact, although humans still seem intent to destroy our close relative’s natural environments.
Some scientists think there is a missing chimp-like knuckle-walking ancestor that led to hominins. Others suspect it’s more likely an ancestor evolved from a species resembling Miocene apes.
Top-Down versus Bottom-Up
Taking a “top-down” approach, some scientists study chimpanzees to attempt to reconstruct hominin origins. Others use a “bottom-up” approach, focusing on the fossil record of mostly extinct apes. Now, reconciling these two approaches “remains at the core of the human origins problem,” the study states.
After the review, the scientists believe it’s “likely that the last shared ape ancestor had its own set of traits, different from those of modern humans and modern apes.”
Therefore, an essential part of the picture remains missing.
Missing Part of the Picture
Study co-author Ashley Hammond says studying living apes isn’t likely to resolve the questions of human origins.
“Living ape species are specialized species, relicts of a much larger group of now extinct apes. When we consider all evidence—that is, both living and fossil apes and hominins—it is clear that a human evolutionary story based on the few ape species currently alive is missing much of the bigger picture,” said Hammond.
In order to unite disparate theories, the study suggests including everything known about hominins, living apes, and Miocene apes in the equation. Importantly, it’s necessary to look at everything to complete the picture.
“Early hominins likely originated in Africa from a Miocene LCA that does not match any living ape (e.g., it might not have been adapted specifically for suspension or knuckle-walking). Despite phylogenetic uncertainties, fossil apes remain essential to reconstruct the ‘starting point’ from which humans and chimpanzees evolved,” states the study.
Darwin’s Theory 150 Years Later
Some 150 years ago, Darwin introduced “In The Descent of Man,” suggesting our origins came from an unknown ancestor in Africa. Today, Darwin’s speculation has been backed up with many discoveries of extinct hominin fossils, but so far, none have proven to be the indisputable missing link.
Darwin’s evolution studies once led to him being dubbed “the most dangerous man in England,” for upsetting religious ideas. However, he almost became religious clergy himself and at one time believed in the “strict and literal truth of every word in the Bible.”
Then, an 1831 trip on the HMS Beagle to South America changed his life. After he arrived at the Galapagos, his studies of flora and fauna eventually led to the theory of evolution by natural selection. He presented overwhelming evidence in 1859 in The Origin of Species, criticized by clergy and even some of his own family but supported by important scientists.
Gradually, Darwin’s theory became widely accepted.
See more from Biographics:
You might like: Scientists genetically link orangutans to giant ape thought to be Bigfoot
Zecharia Sitchin and the Missing Link
Like Darwin, author Zecharia Sitchin is highly controversial but remains so after his death. Unlike Darwin, Stichin focused on translations of ancient Sumerian and Akkadian clay tablets, with no scientific evidence.
In seven books known as The Earth Chronicles, Sitchin suggested a radical human origins story. Humans were genetically engineered by extraterrestrials called the Anunnaki, who arrived on Earth 450,000 years ago.
“According to Sitchin, an advanced race of human-like extraterrestrials called the Anunnaki live on Nibiru and are the missing link in Homo sapiens evolution,” writes a critical review by Ohio State University.
Like today’s scientists, Sitchin believed human origins began in Africa, where the Anunnaki mined gold. Once they arrived, they genetically altered early humans, creating a suitable slave race for mining operations.
As outrageous as the ideas sound, it’s one idea why the missing link in human evolution remains as of yet undiscovered. If true, our ancestors got a jumpstart, a boost in intelligence by rather unnatural ET selection. However, it would not disprove Darwinian evolution but suggest that human intelligence got an evolutionary boost.
Before his death in 2010, Sitchin urged scientific DNA testing to confirm if his ideas could be true. He was willing to stake his life’s work to determine if extraterrestrials had indeed once lived among humans. However, the testing, thus far, has either not been done or has not been reported. Nevertheless, Sitchin’s work remains fascinating to ancient astronaut theorists.
Until we conclusively discover a missing link, human origins will remain a fascinating mystery. For some, religion and spirituality fill in the gaps, for others, science is the only acceptable method. Perhaps, as the scientists in the recent study believe, solving the mystery will require being open to everything in the picture.
To see more by this author follow The Gamut.
Featured image: Image by jplenio via Pixabay, Pixabay License