Top Paleoanthropological Discoveries of 2021
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The Scientific World is that of an ever-changing landscape. Of a desert turned lush forest, to the Savannah, and back again. The field is ever-changing, ever-adapting. Within the STEM fields, some are more active than others, with some fields breaking the headlines with discoveries daily, while others on a more, centurion basis. Paleoanthropology, or the study of human origins, is one of the fastest-changing fields in Science. It seems that every time something is discovered, or a question answered and settled upon, some new evidence or idea comes around that throws near everything up in the air, changing the landscape once again. Just in the last decade, the field as we know it is has changed so abruptly that it is near unrecognizable to what it was just fifty years ago! And this is a good thing! Science should not be stagnant, which means it is not science, for science is the act of experimenting, and finding out about the world around you! If you stop doing that, you are no longer a scientist. There will never be a point where we ‘know everything. As is my motto, “there is always more to learn!”
So, today I would like to gather your attention, as we near the coming of the end of 2021, to some of the biggest discoveries in the field of Paleoanthropology to occur. I had a very rough time choosing the following, and while there are ten, and this is a ‘Top Ten List’ the ones in this list are in no particular order. I do not view that any find is necessarily “better” than any other, as they all have their importance in their ways. So appreciate them all on their merit! What was your favorite event from 2021, let me know in the comments below! I would love to hear it!
Let’s get started!
Number One: A Child out of the Darkness of Rising Star…
To start off this list, I think it is fair enough, to begin with, my personal favorite. Again, this find is not necessarily more important than any other on this list, it just happens to be my personal favorite! Before we get into this portion, some background is needed.
In 2013, Lee Berger and his team of ‘Underground Astronauts’ (A team of thinly built women, perfect for fitting and squeezing into tight cave spaces) conducted one of the now most famous Anthropological excavations in history; for discovered in the deep recess of the Rising Star Cave system, in the Cradle of Humankind, South Africa, was a new type of human. Homo naledi.
Eventually, over 2,000 individual fossil fragments would be excavated, from over fifteen individuals, including the partial skeleton of Neo, a near-complete specimen found in the Lasedi chamber, a few years after the initial excavation. H. naledi is a very unique hominin, displaying a mosaic of features, and dating to only 240-320 kya. These hominins even show signs of advanced behavior, and even possible understanding of, and purposeful burial within the cave system.
In November of 2021, two papers were published in Nature, (Brophy et al./Elliott et al.) detailing the discovery, and recovery of 28 skull fragments from a small crevice, 15cm wide, 80cm long, that would turn out to be the partial skull of a Homo naledi child. Aged four to six years old, with a brain cc of 480-610 this adolescent would have had nearly the size of an adult brain by the time it died, and was interned even deeper within the cave, in a chamber dubbed the ‘Chaos Chamber’
The specimen was dubbed “Letimela” or “Leti” for short meaning
‘Lost one’ in Setswana. The discovery of Leti, adds another layer to the hypothesis that naledi was using the Rising Star cave system as a burial ground, something unobserved in earlier hominins. This could change our understanding of death, and how it evolved, understanding where our beliefs surrounding originated can help us understand our fears, and challenges with it today.
Number Two: Australopithecus sediba walked like a human, but climbed like an ape!
Another discovery coming out of Lee Berger, well, technically his son at the age of nine years old in 2008 discovered what would soon be named Australopithecus sediba a new species of hominin. The discovery was made at Malapa, in the Gauteng Province, once again in the Cradle of Humankind, South Africa. Originally, two individuals were discovered, MH1, dubbed ‘Kurabo’, a beautiful skull of an adolescent. And MH2, a female.
The remains dated to about 2 mya, well older than Berger’s later work with naledi. The limbs of sediba made it clear, at least at the time, that this hominin was an arboreal primate, that it lived in the trees for most of its time, and most likely spent little time on the ground walking bipedally. However, as published in November 2021 as well, with Berger as the lead author, a block of breccia that was recovered from the original site in 2015, was placed in a high-resolution micro-CT scanner, and it was revealed that in this block, there were five lumbar vertebrae belonging to MH2, even showing a lumbar lordosis.
While the upper limbs of sediba were outfitted for life in the trees, the lower spine of sediba was evidence that this hominin was also an obligate terrestrial biped! This sheds light on the origins of bipedality, and when we left the trees for life on the ground! While behavior does not fossilize, and we cannot know for sure just how sediba acted and lived its life, we do have a much more interesting look now that we have these fossils.
Now that we possess the near complete lower spine of MH2, Berger felt it was time to give the partial skeleton a name, ‘Issa’ meaning “protector” in Swahili, as it seems she may have been of the younger Kurabo.
Number Three: Stone Tools in Oldupai Gorge Pushed Back to Two Million Years Ago!
Oldupai Gorge, formerly known as Olduvai Gorge, made famous by the Leakey’s in the 1970s, is home to many hominin-related fossils, from the discovery of H.
habilis and Zinj, to many stone tools, such as the entire Oldowan Stone Tool Complex. This is a very famous site, and for a long period of time, was considered to be the very birthplace of humankind. While this is debatable now, it is clear that there is a great his- tory here. This year, new tools were discovered in the 28-mile long gorge, by Michael Petraglia and the Max Plank Institute for Science of Human History. This predates the Oldowan industries for the Eastern side of the basin by 180,000 years. Pushing stone tool use to near 2 mya. It has become clear that “rapid environmental change is the catalyst for human evolution”. Stone tools and their use for them adapted relativity quickly in the scheme of things, and allowed our ancestors to do things that no other animal had ever been able to do, or since. Published in Nature by Mercader et al, this paper details the new dating of the stone tools, and reveals that as usual, we do not know the entire story and that there is always more to learn!
Number Four: Humans in North America 23 kya!
For the next item on our list, we have something quite special, for decades now, anthropologists have debated on where, when, and how humans got to the New World, the Americas. There have been many prevailing hypotheses based on current evidence, starting with the Bearing Land Bridge, and the Clovis people, to people crossing the Atlantic Ocean and landing on the East Coast of the Americas. There have been oh so many ideas and theories, with various endings and evidence. Some even support humans on the continent 120 kya butchering mammoth! While this find, in San Diego has been highly disputed, the recent find at Lake Ohro, White Sands National Park, New Mexico. As described by Dr. Matthew Bennet et al., this confirms the presence of humans in the Americas 21-23k years earlier than the typical scientific consensus, confirming their presence in North America 23 thousand years ago!
Created during a warm period in the last interglacial period, the last glacial maximum, the paper published in Science, details the new prints and how they were dated. Tom Higham, from the University of Vienna, an expert in radiocarbon dating, who was not involved in the study, was very impressed by the work that was done, saying that he was “very confident in the results”. Comprising of nearly 60 fossilized prints, mostly from those of adolescents, the footprints are a truly remarkable discovery.
Number Five: A new human relative, Homo longi?
One of the most exciting discoveries of the year, and I know, I am probably saying that about most of these, was the re-discovery and announcement of the Harbin Skull. Originally discovered in the early 1900s and hidden down a well to protect it from invaders, the Harbin skull was located near the Dragon River, in Harbin, Northeast China. Being in near perfect condition, the preservation for this near 146 thousand-year-old cranium is very impressive. According to Prof. Qiang Ji from Hebei GEO University, this is a representative of an archaic homo sapiens, with a very large cranium, a cc of 1,420, well within the range of modern-day humans and Neanderthals.
With impressively large, square eye orbits, this cranium has warranted the name of a new species, and has been dubbed ‘Homo longi’ this, however, according to Chris Stringer may not be appropriate for a few reasons, as a close team member who worked on the Harbin Cranium over the last few years before these papers were published, Dr. Stringer has a unique insight on the skull. We even had him on the show to talk about it. Be sure to check out that episode of The Story of Us!
Nicknamed ‘Dragon-Man’, this specimen could even be physical remains of the previously mostly known by DNA species, the Denisovans. Since we have not found a complete skull or any cranial fragments to mention, we are unsure if the Harbin cranium ought to belong to a new species, or to the Denisovans, which have yet to be given an official taxonomic designation themselves. Being the second-largest cranium in the fossil record, many mysteries are remaining surrounding this skull.
Thought to be around a fifty-year-old male, who lived 138-309 kya, this fossil, if a Denisovan, would be more genetically related to us than even Neanderthals, as shown by other archaic DNA research done by the Max Planck Institute for Evolutionary Sciences. Could this be a new sister group to H. Sapiens? Until we can get DNA from the cranium itself, it will be hard, if not impossible to tell without knowing where the skull originated from since it was not found in situ but rather in said well! But it is sure fun to think that we may have a whole new relative represented by this cranium, which does share resemblances and morphological features with other Asian hominin fossils, such as the Dahli skull.
Only time will tell!
Number Six: New Analysis of ‘Track A’ Prints at Laetoli, Tanzania!
While this discovery is not new per-say, the analysis of what was already there has revealed some very interesting, and enlightening information! The Laetoli Footprints are a very famous archaeological site in Tanzania, discovered by Mary Leakey in the 1970s, thanks to an elephant dung fight! What Mary Leakey discovered, were a set of tracks, that were later determined to be those belonging to A. afarensis aka the species that Lucy belongs to. These tracks, among 18,400 total animal prints, dating back to 3.66 mya, were then reburied and left to be analyzed at a later time.
One set of the tracks, the ‘A Track’ was quite curious. The prints did not belong to A. afarensis, as they differed quite drastically not only from the other prints themselves but of other hominin feet we have found thus far.
In a new paper, published in Nature by Dr. Ellison McNutt et al. another guest of our show (you can view that episode to learn all about this find!), sent a team back to Laetoli to find, and re-excavate the ‘Track A’ prints. Amazingly, thanks to the great and detailed maps that Mary made, Prof. Jeremy DeSilva (yet another friend of the show!) And the team was able to find the original tracks!
After new analysis, the five prints that were discovered, that were originally attributed to some kind of upright walking bear, were determined to be none other than that of a hominin! While there is no way to know just which hominin these tracks belong to, not without some fossil evidence, it is clear that this is a different species than the ones made by afarensis. This is significant because the tracks were made in volcanic ash, which is why they were so well preserved. However, this also means that all of the 18k+ tracks were made in a short period. Meaning, these two different species of hominin could have looked across the field at each other! Who knows what they saw! We may never know! What we do know, is this lends more evidence to the “muddle in the middle”, the idea, and what is becoming more of a fact, that multiple hominin species were coexisting and living in the same place, and time as each other!
There is going to be very exciting news coming out of Laetoli in the future, I just know it!
Number Seven: Neanderthal Terraforming?
I know you might be saying to yourself, “Did I read that correctly?” At least that is what I found myself doing when this paper was published only in the last few weeks! Terraforming, to me, seems to be something we do on other worlds, on planets in science fiction movies, not on Earth, and even if it is, surely it is done by modern humans. Wrong! Or so it would seem!
Firstly, I think it is important to define what we are talking about, no we are not talking about changing entire planetary atmospheres to make living on an entirely inhospitable planet possible. Rather, changing local environments over time to make them more beneficial to the population currently calling that area home.
At the German site of Neumark-Nord, there is evidence of a continuous 2k year population of Neanderthals who transformed the area from woodland to grassland! This was found out by tracing the pollens in the different layers of sediment, and it was very clear that the pollens changed drastically during this two thousand-year period, far faster than they ever would have naturally.
We know by the stone tools and other archaeological and fossil evidence that Neanderthals occupied this site 125 kya. Not only does this show that Neanderthals, and not just modern humans were capable of making drastic changes to their local landscape, but also gives evidence of sustained Neanderthal living in larger groups than previously thought. Meaning that different populations and groups possibly lived in different manners, depending on where they were within the wide range that the Neanderthals called home.
Number Eight: Nesher Ramla, a Second New Member of the Family Tree for 2021?
For many decades now, it has been known to evolutionary biologists, that the Levant, or an area of the Middle East, has been a passageway, and home to many hominids over the last million years or so. From Homo erectus to Neanderthals, and our very own ancestors, modern humans. And now, there is evidence that another hominin not only passed through this way but called it home and possibly adapted to the local environment in some unique and special ways.
Published in Science by Israel Hershkowitz and Yossi Zaidner, the analysis of various cranial remains, that were once designated to belong to Neanderthals at the site of Nesher Ramla. The fossils date to between 120-420 kya and have some unique features, that almost appear to be a mix between modern humans and Neanderthals! While we cannot know that for sure without DNA evidence (which I am sure they are attempting to gather as we have done with Denisovans and Neanderthals) but that will remain to be seen.
Some scientists disagree with the new designation, citing that the changes fall within regular late Pleistocene human variation. What this does suggest though however, is that there was likely heavy gene flow between eastern Neanderthals, and anatomically modern Homo sapiens as they came up north out of Africa.
Along with any organic fossils remains that were found, there were also six thousand stone tools found at the site! So whoever was here, clearly had a well-adapted and advanced culture.
Number Nine: A Third New Member of the Human Family Tree? Not so fast…
We are almost getting to the end of the list! If you have made it this far, I commend you! What a journey through the many discoveries of 2021 this has been! Let’s keep going and finish strong!
While this is not necessarily about a new discovery, it is about new analysis and proposal that has been put forward in the Journal of Evolutionary Anthropology. The idea is that H. hiedelbergensis and H. rhodensiensis taxonomic names should be thrown out, and rather than that, combined, and placed in the new taxonomic designation “Homo bodoensis”. The paper continues on to say that some of the fossils classified to those two branches should be adjusted, such as the Sima de los huesos hominins, which many argue were Neanderthals to begin with, such as Chris Stringer, who also goes on to note that this is highly debatable because this may only add to the “muddle in the middle” as anthropologists call it. A period of time in the middle of the Pleistocene where the fossil record is sparse, and there is much to learn.
The problem with naming these hominins this way, and placing them within their taxonomic clade, is that there have been other taxons named first that these proposed fossils would belong to, instead of this new name. The law of taxonomy states that the first name is given, is to be the scientific name. So to remain these, without good reason, and to something wholly new while other names already exist, is hard to establish.
Despite this, many anthropologists are loving the idea, basing it on the Bodo Cranium, claiming it is ancestral to AMH (Stringer does not agree). The paper goes on to cite evidence that may support the idea that Asiatic hominins had a different evolutionary path as well, leading to Denisovans, or others later on. However, some anthropologists do not agree with the idea that the Bodo cranium has ancestral features to modern humans.
So while this is big news, and since much of the scientific community has accepted this, it is clear it will not be going away any time soon! Again, while not a discovery, this new idea could change how we view cladistics, and how we operate concerning unknown species, and the muddle in the middle!
Number Ten: Denisovan DNA From Cave Sediments!
To round off the list, we have something very exciting, and something that seems like it is straight out of science fiction! This year, for the first time, we have been able to recover hominin DNA straight from sediments in which they occupied millennia ago! While DNA extraction from sediments and other such materials is not new, it is the first time it was successfully applied in this way.
According to what was found in the sediments at Denisova Cave, Siberia, Russia, hominins continually had a presence at the cave for over 300,000 years. These were not all the same species, however, but rather Neanderthals, Modern Humans, and Denisovans, at least that we know of so far. There is even evidence of cohabitation between species at different times.
According to Michael Shakov in Nature, and covered by Science Daily, this is the largest sediment analysis of DNA at a single site. MtDNA was recovered from all three species mentioned above in groundbreaking studies led by the Max Planck Institute, and lead author Elena Zavala. The different layers showed varying levels of technology depending on which species was present at the time. Denisovans hold the longest run at the cave, arriving first, followed by Neanderthals, and lastly by us.
This new find is going to answer plenty of questions about the interactions between the three sister groups, as well as hopefully provide archaeological methods that will help in the recovery of DNA from other areas, perhaps from the sediments of Rising Star? One can only hope and dream!
What an absolutely amazing year it has been for Human Evolution Studies! It seems that the more we explore, the more we learn and discover the more and more there is to learn! If we answer a burning question that we have, five more arise in its absence. It is truly an ever-growing, and one of the fastest-moving fields that I know of. So many amazing, and utterly groundbreaking discoveries over the last year have shaped and prepped the field for a big year in 2022. While the pandemic has ranged around the world and put a halt to so many things, nothing can stop the burning desire to learn and discover. Hopefully, you learned a great deal not only about just what was discovered over the last year but about Paleoanthropology in general, at least that is my hope. I know this article is a tad long…but I figure we can all enjoy it over the Holidays!
What are your favorite finds from 2021? Share in the comment section!
Whatever you celebrate, wherever you are, whoever you are, remember we are all human, we are all in this together, be happy, be merry, and Happy Holidays!
Here is to a bright, and powerful New Year for us all!
Be sure not to miss our upcoming Neanderthal Symposium in January 2022!!!
World of Paleoanthropology