Middle Pleistocene Homo naledi

John Hawks discusses the latest news on the Rising Star Project:

Africa’s richest fossil hominin site has revealed more of its treasure. It’s been a year and a half since scientists announced that a new hominin species, which they called Homo naledi, had been discovered in the Rising Star Cave outside Johannesburg.

Now they say they have established and published the age of the original naledi fossils that garnered global headlines in 2015. Homo naledi lived sometime between 335 and 236 thousand years ago, making it relatively young.

They’ve also announced the discovery of a second chamber in the Rising Star cave system, which contained additional Homo naledi specimens. These include a child and the partial skeleton of an adult male with a well-preserved skull. They have named the skeleton “Neo” – a Sesotho word meaning “a gift”.

The Conversation Africa’s Science Editor Natasha Joseph asked Professor John Hawks, a member of the team, to explain the story behind these finds.

To an ordinary person, 236 000 years is a very long time ago. Why does the team suggest that in fact, Homo naledi is a “young” species?

The course of human evolution has taken the last seven million years since our ancestors diverged from those of chimpanzees and bonobos. The first two-thirds of that long history, called australopiths, were apelike creatures who developed the trick of walking upright on two legs.

Around two million years ago some varieties of hominins took the first real steps in a human direction. They’re the earliest clear members of our genus, Homo, and belong to species like Homo habilis, Homo erectus and Homo rudolfensis.

Homo naledi looks in many ways like these first members of Homo. It’s even more primitive than these species in many ways, and has a smaller brain than any of them. People outside our team who have studied the fossils mostly thought they should be around the same age. A few had the radical idea that H. naledi might have lived more recently, maybe around 900,000 years ago.

Nobody thought that these fossils could actually have come from the same recent time interval when modern humans were evolving, a mere 236 to 335 thousand years ago.

How do you figure out a fossil’s age?

We applied six different methods. The most valuable of these were electron spin resonance (ESR) dating, and uranium-thorium (U-Th) dating. ESR relies on the fact that teeth contain tiny crystals, and the electron energy in these crystals is affected by natural radiation in the ground over long periods of time after fossils are buried.

U-Th relies on the fact that water drips into caves and forms layers of calcite, which contain traces of uranium. The radioactive fraction of uranium decays into thorium slowly over time. So the proportion of thorium compared to uranium gives an estimate of the time since the calcite layers formed. One of these calcite deposits, called a flowstone, formed above the H. naledi fossils in the Dinaledi Chamber. That flowstone helps to establish the minimum age: the fossils must be older than the flowstone above them.

For these two methods, our team engaged two separate labs and asked them to process and analyse samples without talking to each other. Their processes produced the same results. This gives us great confidence that the results are reliable.

What does the discovery of Homo naledi’s age mean for our understanding of human history and evolution?

For at least the past 100 years, anthropologists have assumed that most of the evolution of Homo was a story of progress: brains got bigger over time, technology became more sophisticated and teeth got smaller as people relied more upon cleverness to get better food and prepare it by cooking.

We thought that once culture really got started, our evolution was driven by a feedback loop – better food allowed bigger brains, more clever adaptations, more sophisticated communication. That enabled better technology, which yielded more food, and so on like a snowball rolling downhill.

No other hominin species could compete with this human juggernaut. You would never see more than one form of human in a single part of the world, because the competition would be too intense. Other forms, like Neanderthals, existed within regions of the world apart from the mainstream leading to modern humans in Africa. But even they were basically human with large brains.

That thinking was wrong.

Africa south of the equator is the core of human evolutionary history. That’s where today’s human populations were most genetically diverse, and that diversity is just a small part of what once existed there. Different lineages of archaic humans once lived in this region. Anthropologists have found a few fossil remnants of these archaic populations. They’ve tried to connect those remnants in a straight line. But the genetic evidence suggests that they were much more complex, with deep divisions that occasionally intertwined.

H. naledi shows a lineage that existed for probably more than a million years, maybe two million years, from the time it branched from our family tree up to the last 300,000 years. During all this time, it lived in Africa with archaic lineages of humans, with the ancestors of modern humans, maybe with early modern humans themselves. It’s strikingly different from any of these other human forms, so primitive in many aspects. It represents a lost hominin community within which our species evolved.

I think we have to reexamine much of what we thought we knew about our shared evolutionary past in Africa. We know a lot of information from a few very tiny geographic areas. But the largest parts of the continent are unknown – they have no fossil record at all.

Explorers Mathabela Tsikoane, Maropeng Ramalepa, Dirk van Rooyen, Steven Tucker (seated), and Rick Hunter (seated) inside the Rising Star cave system. Wits University/Marina Elliott

We’re working to change that, and as our team and others make new discoveries, I’m pretty sure we are going to find more lineages that have been hidden to us. H. naledi will not be the last.

The first Homo naledi discoveries were made in the Dinaledi Chamber. What led researchers to the second chamber? And what did you find there?

The Dinaledi Chamber is one of the most significant fossil finds in history. After excavating only a very tiny part of this chamber, the sample of hominin specimens is already larger than any other single assemblage in Africa.

The explorers who first found these bones, Rick Hunter and Steven Tucker, saw what the team was doing when they were excavating in the chamber. The pair realised that they might have seen a similar occurrence in another part of the cave system. The Rising Star system has more than two kilometres of mapped passages underground. In another deep chamber, accessed again through very tight underground squeezes, there were hominin bones exposed on the surface.

Our team first began systematic survey of this chamber, which we named the Lesedi Chamber, in 2014. For two years Marina Elliott led excavations, joined at times by most of the team’s other experienced underground excavators. They were working in a situation where bones are jammed into a tight blind tunnel. Only one excavator can fit at a time, belly-down, feet sticking out. It is an incredibly challenging excavation circumstance.

Geologist Dr Hannah Hilbert-Wolf studying difficult to reach flowstones in a small side passage in the Dinaledi Chamber. Wits University

The most significant discovery is a partial skeleton of H. naledi, with parts of the arms, legs, a lot of the spine and many other pieces, as well as a beautifully complete skull and jaw. We named this skeleton “Neo”. We also recovered fragments of at least one other adult individual, and one child, although we suspect these bones may come from one or two more individuals.

Is there a way for people to view these discoveries in person?

On May 25 – Africa DayMaropeng at the Cradle of Humankind World Heritage Site outside Johannesburg will open a new exhibit with the discoveries from the Lesedi Chamber and the Dinaledi Chamber together for the first time.

For people outside South Africa, the data from our three-dimensional scans of the new Lesedi fossils are available online.

Anyone can download the 3D models, and people with access to a 3D printer can print their own physical copies of the new fossils, as well as the fossils from the Dinaledi Chamber. It’s a great way for people to see the evidence for themselves.

Reprint from The Conversation

DNA reveals Aboriginal people had a long and settled connection to country

Historic hair samples collected from Aboriginal people show that following an initial migration 50,000 years ago, populations spread rapidly around the east and west coasts of Australia.

Our research, published in Nature today, also shows that once settled, Aboriginal groups remained in their discrete geographical regions right up until the arrival of Europeans a few hundred years ago.

So where does the evidence for this rapid migration and long settlement come from?

Early expeditions

In a series of remarkable expeditions that ran from the 1920s to 1960s, scientists travelled widely across the Australian outback. They recorded as much anthropological information as possible about Aboriginal Australians.

They recorded film and audio, drawings, songlines, genealogies and extensive physical measurements under tough outback conditions. This included packing in the equipment on camels for the early trips.

Alan Rau, EO Stocker and Herbert Wilkinson on an expedition party departing for a day’s trip from Cockatoo Creek, Central Australia, 1931. South Australian Museum Archives Norman Tindale Collection (AA 338/5/7/8), Author provided

The extensive collections from the Board for Anthropological Expeditions are now curated in the South Australian Museum. They contain the vast majority of the black and white film footage you may have seen of traditional Aboriginal culture, songs, hunting practices and ceremonies.

The metadata collected was voluminous. It now comprises possibly the best anthropological collection of an indigenous people in the world.

Locked in the hair

But perhaps the biggest scientific contributions may yet turn out to be hidden within small locks of hair.

These were collected with permission (such as it was given in the situation and era) for a minor project to study the variation of Aboriginal hair types across Australia.

But the hair clippings turn out to preserve an incredible record of the genetic diversity and distribution of Indigenous Australia prior to European disruption.

Importantly, the detailed genealogical data collected with each sample allows the genetic lineages to be placed on the map back through several generations.

This allowed us to reconstruct the genetic structure within Australia prior to the forced relocation of Aboriginal people to missions and stations, sometimes thousands of kilometres from their traditional lands.

Reconnecting histories

This project was only possible through partnership with Aboriginal families and communities. So we needed to design an ethical framework and protocol for such unprecedented work.

This was based on large amounts of archival research performed by our team members in the Aboriginal Family History Unit of the South Australian Museum, to locate and contact the original donors, or their descendants and family elders.

We arranged a meeting time, and then the combined team spent several days in each Aboriginal community talking to individual families about the project, and passing on copies of the archival material.

We discussed both the potential and pitfalls of genetic research, and answered common questions. These included why the results cannot be used for land claim issues (insufficient geographical resolution) or as a test of Aboriginality (which is a cultural, rather than genetic, association).

The feedback from communities was overwhelmingly positive. There was a strong interest in how a genetic map of Aboriginal Australia could help people of the stolen generation to reconnect with family and country.

It could also help facilitate the repatriation of Aboriginal samples and artefacts held in museums.

The DNA results

The initial genetic results not only reveal exciting insights into the deep genetic history of the continent, but also showcase the enormous potential of our project.

We mapped the maternal genetic lineages onto the birthplace of the oldest recorded maternal ancestor (sometimes two to three generations back) and found there were striking patterns of Australia’s genetic past.

There were many very deep genetic branches, stretching back 45,000 to 50,000 years. We compared these dates to records of the earliest archaeological sites around Australia. We found that the people appear to have arrived in Australia almost exactly 50,000 years ago.

Early migration

Those first Australians entered a landmass we collectively call “Sahul”, where New Guinea was connected to Australia.

The Gulf of Carpentaria was a massive fresh water lake at the time and most likely a very attractive place for the founding population.

The genetic lineages show that the first Aboriginal populations swept around the coasts of Australia in two parallel waves. One went clockwise and the other counter-clockwise, before meeting somewhere in South Australia.

The occupation of the coasts was rapid, perhaps taking no longer than 2,000 to 3,000 years. But after that, the genetic patterns suggest that populations quickly settled down into specific territory or country, and have moved very little since.

The genetic lineages within each region are clearly very divergent. They tell us that people – once settled in a particular landscape – stayed connected within their realms for up to 50,000 years despite huge environmental and climate changes.

We should remember that this is about ten times as long as all of the European history we’re commonly taught.

This pattern is very unusual elsewhere in the world, and underlines why there might be such remarkable Aboriginal cultural and spiritual connection to land and country.

As Kaurna Elder, Lewis O’Brien, one of the original hair donors and part of the advisory group for the study, put it:

Aboriginal people have always known that we have been on our land since the start of our time, but it is important to have science show that to the rest of the world.

Reprint from The Conversation

How forensic science can unlock the mysteries of human evolution

image-20161220-26741-nuu3lc.JPG

People are fascinated by the use of forensic science to solve crimes. Any science can be forensic when used in the criminal and civil justice system – biology, genetics and chemistry have been applied in this way. Now something rather special is happening: the scientific skill sets developed while investigating crime scenes, homicides and mass fatalities are being put to use outside the courtroom. Forensic anthropology is one field where this is happening.

Loosely defined, forensic anthropology is the analysis of human remains for the purpose of establishing identity in both living and dead individuals. In the case of the dead this often focuses on analyses of the skeleton. But any and all parts of the physical body can be analysed. The forensic anthropologist is an expert at assessing biological sex, age at death, living height and ancestral affinity from the skeleton.

Our newest research has extended forensic science’s reach from the present into prehistory. In the study, published in the Journal of Archaeological Science, we applied common forensic anthropology techniques to investigate the biological sex of artists who lived long before the invention of the written word.

We specifically focused on those who produced a type of art known as a hand stencil. We applied forensic biometrics to produce statistically robust results which, we hope, will offset some of the problems archaeological researchers have encountered in dealing with this ancient art form.

Sexing rock art

Ancient hand stencils were made by blowing, spitting or stippling pigment onto a hand while it was held against a rock surface. This left a negative impression on the rock in the shape of the hand.

Experimental production of a hand stencil. Jason Hall, University of Liverpool

These stencils are frequently found alongside pictorial cave art created during a period known as the Upper Palaeolithic, which started roughly 40 000 years ago.

Archaeologists have long been interested in such art. The presence of a human hand creates a direct, physical connection with an artist who lived millennia ago. Archaeologists have often focused on who made the art – not the individual’s identity, but whether the artist was male or female.

Until now, researchers have focused on studying hand size and finger length to address the artist’s sex. The size and shape of the hand is influenced by biological sex as sex hormones determine the relative length of fingers during development, known as 2D:4D ratios.

But many ratio-based studies applied to rock art have generally been difficult to replicate. They’ve often produced conflicting results. The problem with focusing on hand size and finger length is that two differently shaped hands can have identical linear dimensions and ratios.

To overcome this we adopted an approach based on forensic biometric principles. This promises to be both more statistically robust and more open to replication between researchers in different parts of the world.

The study used a branch of statistics called Geometric Morphometric Methods. The underpinnings of this discipline date back to the early 20th century. More recently computing and digital technology have allowed scientists to capture objects in 2D and 3D before extracting shape and size differences within a common spatial framework.

In our study we used experimentally produced stencils from 132 volunteers. The stencils were digitised and 19 anatomical landmarks were applied to each image. These correspond to features on the fingers and palms which are the same between individuals, as depicted in figure 2. This produced a matrix of x-y coordinates of each hand, which represented the shape of each hand as the equivalent of a map reference system.

Figure 2. Geometric morphometric landmarks applied to an experimentally produced hand stencil. This shows the 19 geometric landmarks applied to a hand. Emma Nelson, University of Liverpool

We used a technique called Procrustes superimposition to move and translate each hand outline into the same spatial framework and scale them against each other. This made the difference between individuals and sexes objectively apparent.

Procrustes also allowed us to treat shape and size as discrete entities, analysing them either independently or together. Then we applied discriminant statistics to investigate which component of hand form could best be used to assess whether an outline was from a male or a female. After discrimination we were able to predict the sex of the hand in 83% of cases using a size proxy, but with over 90% accuracy when size and shape of the hand were combined.

An analysis called Partial Least Squares was used to treat the hand as discrete anatomical units; that is, palm and fingers independently. Rather surprisingly the shape of the palm was a much better indicator of the sex of the hand than the fingers. This goes counter to received wisdom.

This would allow us to predict sex in hand stencils which have missing digits – a common issue in Palaeolithic rock art – where whole or part fingers are often missing or obscured.

Palaeo-forensics

This study adds to the body of research that has already used forensic science to understand prehistory. Beyond rock art, forensic anthropology is helping to develop the emergent field of palaeo-forensics: the application of forensic analyses into the deep past.

For instance, we have been able to understand fatal falls in Australopithecus sediba from Malapa and primitive mortuary practices in the species Homo naledi from Rising Star Cave, both in South Africa.

All of this shows the synergy that arises when the palaeo, archaeological and forensic sciences are brought together to advance humans’ understanding of the past.

The above article was reprinted from The Conversation

17 Palaeoanthropological Terms in Irish / 17 Téarmaí Pailéantraipeolaíochta as Gaeilge

Here are just some of the words, that you are likely to use in discussion of human evolutionary research. For more information regarding how to pronounce the words check out the video below.
Gaeilge To English
Pailéantraipeolaíocht – Palaeoanthropology

Anailís Lithic – Lithic Analysis

Seandálaíocht – Archaeology

Astrálaipiticín – Australopithecine

Scaipeadh – Dispersal

Bhreismheascadh – Admixture

Antrapóideach – Anthropoid

Pléisticéineach – Pleistocene

Geomoirfeolaíocht – Geomorphology

Bunús Daonna – Human Origins

Daoine anatamaíoch Nua-aimseartha – Anatomically Modern
Human

Ilchríoch – Continent

An Afraic – Africa

An Eoráise – Eurasia

Anailís Timpeallachta – Environmental Analysis

Dátú Argón-Argón – Argon/Argon Dating

Anailís Ghéiniteach – Genetic Analysis

______________________________________________________________________________________________________

Social Media Destinations:
Facebook: https://www.facebook.com/charlesgfclarke

Twitter: https://twitter.com/Cennathis

Google+: https://plus.google.com/113974359890947358730/posts

WordPress: http://palaeofocus.com/

Tumblr: https://www.tumblr.com/blog/cennathis

Academia.edu: https://ucl.academia.edu/charlestgclarke

SoundCloud: https://soundcloud.com/charlestgclarke

Three things humanity can do to develop more respect for woman

In recent days youtube has lit up with videos about catcalling. An individual, nearly always male, shouts unflattering comments at a particular woman about how she looks, in public, on the streets. The unflattering aspect is, these women are objectified, a disrespectful mannerism.

I came across this video today:

This is very interesting and expected. There is a level of Islamophobia generally in the West. This manifests itself in various levels of intensity. So, this may explain the lack of catcalling to a degree.

Now, the Hijab-to-counteract-catcalling hypothesis is no excuse to legitimise the wearing of the Hijab. Traditionally the wearing of such is required by Allah, by Islam and as is well known this belief system is a figment of humanity’s imagination. From a Muslim standpoint, this video will be referenced to legitimise the Hijab wearing. It superficially halts catcalling. That’s fine, but men will always be men. Read on……

I want to address the issue of catcalling. Let’s examine all the cities of the world to see what results we would gain their. Of course, it depends upon the area you pass. Passing a red light district will give a particular set of results, while passing a financial district will give another. If you do not want to be catcalled avoid a red light district for example.

OK, so if you live in an area with high catcalling rates, nothing can be done in the short term. But long term, male attitudes need to change and raising awareness helps.

Afro-americans are unfairly represented, in my opinion. They will be maligned a great deal by this. Now, there are 20 hours of footage here…………..what was edited out. If the selection actually reflects an average for that twenty hours, then we are looking at a human male culture that has not changed with the times.

As male ape’s, we are no different from males of other genera. We are evolutionarily set to check out the opposite sex. Just read the selfish gene. Ultimately, some are asking for males to change their attitude. Truth is it’s hard to reverse millions of years of evolutionary statis. Culture has only recently developed exponentially over the last 200,000 years. Change will not come overnight while a sexdrive is around.

The rise of Islam, is subjugation of the feminine on an infamous epic scale. The West continued to surge ahead with progress, leaving Arabia behind in the smoke and dust. When I refer to the West, I’m not talking about the US and Europe, I’m talking about those regions of the North American, mainland SE Asian and European continents which were greatly influenced by the enlightenment of the 18th century onwards. Places where learning and knowledge are valued and Scientific methodology prevail.

There are locations, for example segments of New York or the American midwest or the Tabloid reading demographic, where this is not the case. Homophobia, sexism, rascism and religious tolerance still persists to varying degrees. All that can be done here is

1. stop buying gutter journalism. Need I say more…
2. Raise awareness of accepted and unexaggerated political correction ((respect for women: stop catcalling), rascism, homophobia)
3. Vote Democrate (if state-side)
4. Understand that we are all animals and if we keep that in mind, we will accept being evolutionarily driven organisms with one goal the desire to procreate.

Summary: How do you stop catcalling? Hijab is not the answer, raising awareness is. But know that it is going to take some time before catcalling diminishes on city streets. Doesn’t mean it will disappear, because it won’t. As long as there are two sexes, there will always be catcalling.

P.s: This ignores same-sex catcalling as there is little useful data.

What about insects in hominin diets?

For those fans of human evolutionary research news, you will be well aware of the lack of research into the role insects played in the diet of hominins over the past 6 or so million years.

Image

An Ant! – Credit: Wiki Commons

This topic was addressed back in 2001 in the chapter of an academic volume by William McGrew of the department of Archaeology and Anthropology, University of Cambridge. Since then nothing has been done to address ways in which such an investigation could be conducted. What can be done to address this? Look at what we………..modern primate diets and the role insects play in their diets from the human to the Orang-utan. Let’s then look at the earliest evidence for hominin consumption of insects. South Africa has nabbed that prize, thus far. The Lower Palaeolithic sites of Swartkrans, Sterkfontein and Drimolen contained hominin fossil bone tools with wear patterns similar to those wear patterns you find on sticks used by Chimps to fish for termites. Fossil remains of Paranthropus robustus were found at these sites and the evidence suggests they were feasting on termites.

Image

Paranthropus boisei (Extinct cousin of Paranthropus robustus) – Credit: Wiki Commons

Examining the fossil evidence is one focus, but there are others including, lithics, residues, dental microwear, stable isotopes, DNA and coprolites (Fossilised shit…..basically). The dental microwear is quite problematic, because you have to take note that the tooth has been in the earth for millions of years (2.4 million years for the earliest Paranthropus specimen). Stable isotopic research is the much more promising of the topics discussed in William McGrew’s latest paper for the Journal of Human Evolution.

________________________________________________________

Social Media Destinations:

Facebook: https://www.facebook.com/cennathis

Twitter: https://twitter.com/Cennathis

Google+: https://plus.google.com/+Cennathis/posts

WordPress: https://cennathis.com/

Tumblr: https://www.tumblr.com/blog/cennathis

Academia.edu: https://ucl.academia.edu/charlestgclarke