Join us on a Journey through Deep Human Time…
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Today Genevieve and I will discuss some excellent topics, including stories about Neanderthal Rock Art in France, Australian Cultriual Heritage Sites, and ancient Neolithic Family Trees!
Join us today!
Neanderthals, Naledi, Rock Art, and Geometry! Cave Art 101!
I am so excited to present to you all the next installment of The Q/A version of #CaveArt101 with Genevieve von Petzinger!
Today, the question that we will be answering is “Are there any known percentages of how many cave paintings were painted by children, how many by women, how many by men? Alternatively, is it known that in some locations there are more paintings created by children and in other places more paintings created by women, men and so on? And is it known what?” – Adam Peldaer
What a fascinating, and well-thought-out question! Be sure to catch this episode to hear the answer from our resident rock art expert!
To get your question answered, email them to worldofpaleoanthropology@gmail.com!
https://www.podbean.com/media/share/pb-i5aah-1469bcd
On this episode, and not in this order, join Genevieve and Seth as they discuss some of the newest stories in the field. Learn about new Rock Art discovered in Spain by Drones!, Deep inside ravines on high cliffs, hear about possible cannibalism and cut marks on a nearly 1.6 million-year-old hominin partial tibia (shin bone). Lastly, learn about an ancient First Peoples Oregon settlement dating almost 20,000 years ago! What does this mean for the populating of the Americas?
*TOMORROW*!
*New Episode of “The Story of Us” featuring South African Archaeologist Annalin Matabane! at 9 am Pacific: https://youtu.be/Hq0xhk7Bv_U
Listen to essential stories about “re-humanization” in the aftermath of Apartheid!
*Also: Episode Two of the Paleo Post Podcast, now on Podbean for EVERYONE’s enjoyment!
https://worldofpaleoanthropology.podbean.com
With the lovely Genevieve von Petzinger!
I hope that you guys are enjoying all of the great quality content WOPA has been putting out lately!
So much more to come!
There is always more to learn!
https://www.podbean.com/media/share/pb-4bqa4-1464c31
Go back in time with us as we discover how Neanderthal genetics are still affecting us today and how we now have further evidence of Human activity in South America much earlier than we thought, thanks to some recent discoveries. Finally, we also discuss the amazing science being done with Paranthropus dentition!
Please send all feedback to worldofpaleoanthropology@gmail.com!
Co-Authored with Genevieve von Petzinger As I sit here watching the Press Release on the new naledi findings, I can’t help but feel captivated, …
New Discovery in South Africa Unearths a New Chapter in Human Evolution
The Paleo Post Podcast
Have you ever heard a news story about a paleogenetics breakthrough, a new cave art discovery, or an announcement about an ancient hominin fossil that changes everything? But you’re not sure what that means? Well, the Paleo Post Podcast is here to help! Join us – Genevieve von Petzinger and Seth Chagi, your friendly neighborhood Paleoanthropologists – as we give you the background and the context to be the most interesting person at your next dinner party.
We’ll be covering the big news stories in the field every week, so make sure to tune in every Friday on your Apple Podcasts and other services to follow!
Our mission is to make science fun and accessible, so you can expect to learn cool things about the deep history of humanity, mixed in with lots of nerdy enthusiasm and the occasional bad Paleo pun (what can we say? Paleoanthropology rocks! ha ha ha).
Want to know more about us?
Genevieve von Petzinger is an internationally-recognized Paleoanthropologist studying Ice Age cave art. Her work focuses on geometric signs and what they can tell us about the origins of art, symbolism, and the modern mind. Genevieve has worked at over 100 cave art sites on three continents and officially loves her “job”. The unique database she first built to study the signs at Europe’s 400+ cave art sites is now being expanded to track the movement of people and ideas across the ancient world. Genevieve is a National Geographic Explorer and a TED Senior Fellow, and her TED talk has over 9 million views. She is passionate about science communication and regularly works in media, including print, radio, and television, and has recently been expanding her online outreach with projects like Cave Art 101 and our awesome new podcast 🙂
Seth Chagi is the Project Director and Founder of the Science Communication Project dubbed “The World of Paleoanthropology,” where he gathers news and current events and breaks them down in a fun and educational way for anyone interested. Currently a student, Seth is studying how Hominin brains have evolved and what that has meant for their morphology and behavior. Seth has given several lectures and is an After School Academy Instructor in California. Seth is currently applying to Grad School and looking for his best options, he is very excited for the bright future in Paleoanthropology and Science Communication ahead!
Introduction
Much of the time in paleoanthropology, all we have are fossils. Though we can certainly learn lots about an organism, such as what it looked like, how it lived, and how it evolved, there are some things which simply can not be fully determined just by fossils. Some examples of this are the sex of an organism and its evolutionary relationships.
The sex of an organism is much easier to tell, as many animals possess large amounts of sexual dimorphism, and it is easy to differentiate the sexes based on fossils, but it isn’t always so cut and dry. It is common for mistakes to be made here, such as fossils of two different sexes of the same species being confused for two different species.
Similarly, evolutionary relationships can be told by fossils, but there are many factors which can affect this. For example, two fossils of different species can look very similar, leading people to conclude that they are closely related, but it is always possible that these two species are a result of convergent evolution, and the similar traits are homoplasies rather than synapomorphies, meaning that they evolved independently in the two species.
The best way to determine these things is with ancient DNA (aDNA). Being able to collect, sequence, examine, and compare the DNA of hominins is very useful, but it is rare. We mostly have aDNA from recent, closely related hominins, such as Neanderthals. Even then, much of the Neanderthal genome that we have comes from our own genome, as a result of interbreeding between the two species.
DNA is more accessible from these species because they lived and died much more recently, giving less time for DNA to decay. However, in rare cases, DNA, or at least proteins, can survive for much longer. This is the case for new enamel proteins uncovered from 2 million year old Paranthropus robustus fossils from South Africa, which can have a big impact on the lives and evolution of this strange species.
What is Paranthropus?
Paranthropus is a unique genus of hominin which lived from 2.7-0.1 million years ago (mya). This genus is unique for several reasons. It possessed very specialized cranial anatomy, such as post canine megadontia, large zygomatic bones, and a sagittal crest, all adaptations for a very powerful bite.
These powerful jaws were adapted for chewing through tough vegetation. This is further supported by radiocarbon isotope analysis.
Paranthropus possessed 3 species, P. aethiopicus and P. boisei in eastern Africa, and P. robustus in South Africa. This distribution resulted in them living alongside many other hominins, though this likely wasn’t a problem as they were seemingly eating different things mostly,, resulting in little competition, something known as niche partitioning.
Along with all this, Paranthropus possessed very high levels of sexual dimorphism. Females of all 3 species were much smaller than males, and seem to have lacked notable features of the genus, such as the sagittal crest. I have recently done an article covering everything you need to know about this topic, so you can check that out on this website for more information.
As stated previously, fossils can’t be completely reliable for telling sexual dimorphism, but DNA and proteins can, for the most part. That is where this discovery comes in.
Preservation of DNA and Proteins
The genetic material from Paranthropus is the oldest genetic material from any hominin, being about 2 million years old, but not the oldest genetic material from any hominin ever. Ancient environmental DNA (eDNA) has been collected from faunal and floral assemblages in Kap København Formation in North Greenland. These assemblages were dated to about 1.9-2.1 million years old.
The eDNA showed that the area possessed an open boreal ecosystem, with many different plants, such as poplar, birch and thuja trees, along with various types of Arctic and boreal shrubs and herb. Many of these were not previously recognized in the area from fossils and pollen records.The eDNA also revealed the presence of many different animals, such as mastodons, rodents, hares, and geese. The DNA was preserved in sediments, which preserves DNA better than in bone due to the absorption of minerals which can modify the DNA conformation and prevent enzymatic degradation.
The previous oldest hominin DNA belonged to a 400,000 year old Neanderthal specimen from Spain. Proteins however, which are more resilient than DNA, can survive for longer, but there are many factors for protein preservation. Burial environment, fossil chemistry, time, and temperature are all very important.
Protein sequences have been obtained from ostrich (Struthio camelus) shells in Tanzania dating to 3.8 mya. These proteins were able to preserve for so long because they were encased in the minerals from the eggshells.
800,000 year old tooth proteins have been sequenced from Homo antecessor in Spain, and some from Homo erectus from the Republic of Georgia dating to 1.8 mya.
Genetic Material from Paranthropus robustus
4 dental specimens (SK 850, SK 835, SK 830, and SK 14132) from Swartkrans belonging to Paranthropus robustus cave were sampled. By using mass spectrometry, hundreds of amino acids from the tooth enamel of the specimens. One significant protein found is amelogenin-Y. This protein is produced by the AMELX gene.
This protein is very important formation of tooth enamel. There is one copy of this gene on each sex chromosome. Amelogenin-Y is produced by the AMELY gene on the Y chromosome, but has no effect on enamel formation.
The specimens SK 850 and SK 835 were identified as male based on the presence of amelogenin-Y. This is significant as one of those specimens was originally thought to have been female due to its small size. SK 835 matched the local strontium isotope signal associated with male Paranthropus in the area, making it more likely that this individual was male.
However, Amelogenin-Y was not found in SK 830 and SK 14132. Rather, the X chromosome version of amelogenin-Y, amelogenin X, was found in these specimens.The absence of the amelogenin-Y gene in these specimens doesn’t mean they were automatically female however, as it is possible that it was not detected on them because the proteins were too far out of the detection limit of the instrument used to sequence the proteins.
About 400 of the amino acids sequenced were found in all 4 specimens, showing that modern humans, Neanderthals, and Denisovans are more closely related to each other than any are to Paranthropus, which is not a surprise. Sequence differences were found in one enamel protein, showing genetic variability in the species too. The SK 141132 specimen especially seems to be more unrelated to the rest of the specimens.
Though it is theoretically possible to reconstruct phylogenetic trees of ancient hominins using these proteins, it most likely won’t add much. This is because proteins aren’t very useful for reconstructing evolutionary relationships, and we don’t have any genetic material from other hominins from the time to compare it to. It is best to rely on fossils and skeletal morphology as of right now for determining this.
Conclusion
Proteins are much more resilient when it comes to ancient preservation, so it isn’t that much of a surprise that some were preserved in Paranthropus teeth, a place with plenty of minerals to preserve them in, similar to the 3.8 million year old ostrich protein sequences taken from eggshells.
It is not abnormal for genetic material to be preserved in hominin remains, as there is genetic material as old as 400,000 years old all the way up to 1.8 million years old. It is abnormal however for such old genetic material to be preserved in such an ancient species, making this find especially important.
This discovery has big implications for the sexual dimorphism and biology of Paranthropus. This shows that smaller Paranthropus individuals weren’t necessarily female, meaning that body, cranial, or tooth size may not be as sexually dimorphic as previously thought. This may mean that a reexamination of other Paranthropus specimens may be needed.
It is important to note that the paper this article is based off of is still in preprint, and has not yet been peer reviewed and published, meaning that some of the information may be inaccurate or need revisions. Once it has been reviewed and published, we can truly see the findings of this study and its implications for the lives and evolution of the unique genus of hominin, Paranthropus.
Sources
Endocasts of Homo sapien, Pan troglodytes, and Australopithecus africanus (Beaudet A., 2017).
How are the remains of hominins found at archeological sites used to make inferences about them? We shall walk through the journey of a hominin fossil after it is discovered at a site and processed at a lab with the help of a crude example.
Paleoanthropology is the study of hominins, through their bodily and artefactual remains. It largely relies on making comparisons between the fossils of extinct and extant hominins and sometimes hominids, due to the relative paucity of extinct hominid remains. There are certain tasks before such comparisons can be made.
After the steps necessary for its conservation are undertaken, fossils these days are digitized to virtually slice open and peer through them, allowing the collection of data which would otherwise be inaccessible. This is best done with the help of volumetric scanners, such as Computed Tomography (CT), microCT, Magnetic Resonance Imaging (MRI), and synchrotrons, varying in image resolution and feasibility. Lesser expensive techniques include using surface scanners such as the Breuckmann scanner, laser scanners, or even your phone camera (photogrammetry)!
These scanned 3-D files can be worked on using certain software such as Slicer to manipulate, correct distortions, and reconstruct missing parts of the fossils and in some cases, soft tissue based on patterns seen in the same fossil, or through reference collections. These can also then be exchanged and printed into casts, making it safer and more convenient to study and transmit knowledge among experts and the public.
Once such information is extracted through a single specimen, begins the process of anatomical comparisons using geometric morphometrics. This is a modern-day technique to minimize the influence of variation in the absolute size of crania and that of the scanned 3-D models itself (because of differing reference scales) on the comparative study.
To make the comparisons between fossils of the same bone/complex between specimen, corresponding points on the fossils, called ‘landmarks’ are first defined. These can be based on unique biological characteristics of the bone, geometric features on the bone, or those dependent on other landmarks.
Skulls belonging to gorilla, chimpanzee, modern human, Paranthropus boisei, Homo ergaster, and fossil Homo sapien are compared investigating phylogenetic relationships and cranio-morphological differences.
3-D scans of contemporary and fossil crania from the open-source online repository MorphoSource were used for the analysis. These included 10 samples of Gorilla gorilla, 10 samples of Pan troglodytes (chimpanzee), 10 samples of modern humans from various geographical distributions, and a sample each of Paranthropus boisei (OH 5), Homo ergaster (KNM ER 3733), and a fossil of Homo sapien (from Skhul, Israel).
Ten landmarks were selected across the crania to provide comprehensive information on skull shape. These landmarks are located on the following anatomical points.
| N. | Landmark | Description |
| 1. | Prosthion | Anterior and inferior midpoint of the maxilla. |
| 2. | Nasion | Midpoint of the nasofrontal suture. |
| 3. | Glabella | Midpoint most protruding above the nasofrontal suture, between the arches orbital. |
| 4. | Orbital Frontomalar (L) | Left point located on the orbital rim, on the anterior part of the suture frontozygomatic. |
| 5. | Orbital Frontomalar (R) | Right point located on the orbital rim, on the anterior part of the suture frontozygomatic. |
| 6. | Bregma | Upper and middle point of the frontal, usually located at the junction of the sutures coronal and sagittal. |
| 7. | Opisthocranion | Median point of the skull furthest from the glabella. |
| 8. | Basion | Anterior midpoint of the foramen magnum. |
| 9. | Porion (L) | Highest point of the superior border of the left external auditory meatus, forward and level of the spina supra meatum. |
| 10. | Porion (R) | Highest point of the superior border of the right external auditory meatus, forward and level of the spina supra meatum. |
Fig. 1: Anterior, lateral, and inferior views of the Homo ergaster KNM ER 3773 cranium with landmarks.
The software Landmark Editor v3.0.0.7 by IDAV was used to plot and calculate each landmark’s absolute X-Y-Z coordinate values, although better suited software are available. To optimally align corresponding landmarks across crania against each other and make accurate comparisons, we use Generalized Procustes Analysis.
Generalized Procrustes Analysis (GPA) is a statistical method used in multivariate analysis and data alignment. It is often used in shape analysis but can also be applied to other types of data. In GPA, multiple sets of data, often representing different shapes or configurations, are aligned to a common coordinate system. This is achieved by scaling, rotating, and translating the data points so that they best fit together. The method finds the optimal alignment of the data by minimizing the sum of squared differences between corresponding points across all the datasets.
GPA has been used in this study to minimize the influence of variation in the overall size of crania and that of the scanned 3-D models itself (because of differing reference scales) on the comparative study. The GPA-transformed coordinates of the landmarks are solely based on the variation in shape of the crania and are hence a more accurate measure of inter-species variability.
The software Paleontological Statistics (PAST) v4.03 was used to first transform the previously measured landmark coordinates using 3D procrustes to remove the influence of size and orientation of landmarks on the scanned crania, and then visualized in a Principal Component Analysis plot.
Principal Component Analysis (PCA) is a statistical technique used to simplify complex data, visualize high-dimensional data, and identify underlying patterns in data. PCA is used to identify patterns and relationships in a dataset by transforming the original data into a set of linearly uncorrelated variables called principal components. Reduction in the number of variables in a dataset while retaining as much of the original variation as possible is achieved by identifying the principal components that explain the most variance in the data. The first two principal components are the directions of greatest variance in the data and are hence primarily used in the plot.
In the present study, the GPA-transformed coordinates of landmarks were used in PCA to qualitatively assess inter-species variation among various hominids of the past and present based on the chosen landmarks.
The resulting scatter plot using PCA termed morphospace (Fig.s 2 and 3) is mostly consistent with the generally accepted phylogeny. There is a clear clustering of gorilla, chimpanzee, and modern human groups of individuals, although a slight overlap exists between gorilla and chimpanzee.
The P. boisei from OH 5 is located roughly between, although below gorilla and chimpanzee. serves to disprove the linearity of evolution, especially that of humans. Being the most robust of its genus, “Zinj” lived approximately 1.8 million years ago and had developed powerful jaw muscles and large molars capable of grinding hard foods, although it was likely a generalist. In contrast, chimpanzees diverged from the hominin line 6-8 million years ago but evolved craniofacial features “statistically closer” to sapiens than P. boisei did, also evidenced to being omnivores.
The 80000–120000-year-old sapien from Skhul is the closest fossil used in this study to modern humans. However, it is not within the convex hull of modern humans indicating that significant changes have occurred in sapien crania ever since, questioning the usage of the term “anatomically modern humans” to refer to all sapiens after 300000 years.
H. ergaster from Koobi Fora is located almost exactly midway between P. boisei and sapien (Skhul) on the morphospace, which is expected, given that it lived approximately 1.6 million years ago and was a member of our genus.
Fig. 2: Scatter plot of PCA without biplot.
Further, it can also be seen in Fig. 3 that raw coordinates 19, 20, and 30 vary the most along PC 2 and hence are the greatest differential between gorilla, chimpanzee and modern humans. These correspond to X and Y-coordinates of opisthocranion and the Z-coordinate of the right porion. The high inter-species variability in X and Y-coordinates of the opisthocranion is indicative of the expansion of the occipital lobe in our genus and species, which is responsible for visual processing and recognition.
Among the fossils, raw coordinates 15, 16, 17, and 18 seem to vary the most, which correspond to the Z coordinate of the right orbital frontomalar and all 3 coordinates of the bregma. Raw coordinates 1, 4, 7, 10, 22, 23, and 27 vary the least, which correspond to the X-coordinates of prosthion, nasion, left orbital frontomalar, basion, Y-coordinate of basion, Z-coordinates of glabella and left porion.
Fig. 3: Scatter plot of PCA with biplot.
Fig. 4: Coordinate axes.
Among fossil hominins especially, as we move from P. bosei to H. ergaster to H. sapien (Skhul) the progressive decrease in the Y-coordinates of bregma is due to the loss of the sagittal crest and keel. The increase in X and Z-coordinates indicates an expansion in the parietal and frontal lobes, which are associated with sensing, motor function, memory, and supposedly uniquely human traits such as language.
Thus, the study of our deep past today requires modern and futuristic tools while relying on multiple disciplines such as biology, geometry, statistics, and in less crude examples, computer programming.
World of Paleoanthropology