History is a nuanced study. Often, it is not so determinate as it is relative. This is particularly true the deeper we look into the past. Those who try to trace their genealogy are well aware of this.
The science of archeology has its limits. Only so much abracadabra exists in radiocarbon dating, for example. What makes carbon-14 useful for dating some archeological sites is that carbon-14 has a fixed physical "half life". Which is to say, 5568 years, +/- 30 years. This means half of the initial carbon-14 will have decayed in a Neolithic site. But, decay it does. Carbon-14 has an effective limit for radiocarbon dating of about 50,000 years, a date when little if any carbon-14 remains.
So relatively speaking, 50,000 years ago is not all that long ago. On the human timeline, 50,000 years before present (BP) is essentially the boundary between the Middle and the Upper Paleolithic. Put another way, 50,000 BP is approximately the dividing line separating Homo neanderthalensis from our ancient Homo sapiens forebears...with "separating" in quotes.
A growing consensus is forming among paleo-anthropologists. Namely, the human tree is not nearly so bushy as some have claimed--in attempts to graft an endless number of stems upon it. The late Dr. Ernst Mayr (1904-2005) dismissed such human "shrubbery" claims as little more than "beanbag genetics". He acerbically noted that it is surprising how often "false theories" benefit certain scientists, i.e. those who manufacture phantasmagoric "ancestral species" from mere slivers of bone; the beneficial research grants which fund such manufacture notwithstanding.
My personal view is that our modern human lineage indisputably descends through Homo erectus ("upright man"), the longest surviving hominoid "species"--over 1.8 million years--to walk the Earth. Beginning as early as 2.1 to 1.9 million years BP to as late as 100,000 years BP. Anything further afield from this core ancestral trunk is much too speculative, if not specious. In fact, our species is perhaps more properly classified as Homo erectus sapiens rather than the current redundant Homo sapiens sapiens in vogue today. 50,000 BP is not so long ago. It's more or less only 2.5% of the total time--roughly some 2 million years--in which our indisputable human ancestors lived, labored, lamented and loved.
This is not to diminish the utility of the fixed decay rate of carbon-14 for dating. C-14 tests are the work horse of archeological dating. But its use is limited--to sites younger than the end of the Middle Paleolithic. More importantly, radiocarbon dating only works as long as contemporary organic material exists in corroborable strata with other artifacts such as stone tools. Therein is the rub. Organic material doesn't normally stick around long; it doesn't wait to be dated.
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| 16 April 2019 Information sign at Temple Wood, Kilmartin Glen, Scotland |
Point in case is "The Archer's Grave" at Temple Wood Circle in Kilmartin Glen. Temple Wood, as near as can be determined, was first constructed with wood pillars in a circle around a central stone slab about 3,000 BC--Late Neolithic. Some 100 years after (c. 2900 BC), the wooden circle--likely because its posts had decayed with ground contact--was replaced with stone.
At that time, a second stone circle was also constructed. The community apparently then used the site for some 700 years before two short cist graves were built just outside the "newer" stone circle, in or about about 2,300 BC. One cist is known as the "Child's Grave; the other is the "Archer's Grave".
Inside the Archer's Grave, three barbed and tanged flint arrowheads, a Beaker pot and a flint scraper were unearthed in extensive excavations of the site from 1974 to 1980. These artifacts provide a relative dating method...but no human remains were unearthed. All that remains of the "archer's" inhumation were phosphate concentrations in the soil which indicate where and how the body was originally buried...in a fetal position, speculatively signifying returning to Mother Earth.
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| 16 April 2019 diagram of Archer's Grave; left shows soil phosphate concentrations |
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| Archer's Grave artifacts |
The remains completely decomposed, thus providing no recoverable organic carbon, after only 4,200 years. This anecdote emphasizes the difficulties of obtaining accurate absolute dates of human remains, even in sites like the Archer's Grave (a Chalcolithic "Copper" Age site). And it says nothing of dating sites that are hundreds of thousands of years earlier, closer to our species' beginnings.
As an aside, the Child's Grave at Temple Wood produced similar phosphate concentrations. But remarkably, in it a single tooth survived, indicating a child between the age of 4 to 6 years was once buried there.
Of course, archeologists do have other absolute dating tools. For "deep age" sites, Uranium-Thorium-Lead half life decay ratios are used. These can even date rocks--the oldest known being a 4.4 billion year old zirconium rock from Australia.
In addition to absolute dating technology like carbon-14 analysis (and sometimes in lieu of it), relative dating is done using ceramic pottery styles, for example, or stone tool techniques to extrapolate dates.
The Beaker pot found in the Archer's Grave is now housed in Kelvingrove Museum in Glasgow, which we also visited. Being buried with this specific grave good suggests the "archer" was a member of the Beaker culture from continental Europe. Thus, he would have had far different DNA than the farmer culture in the UK which migrated into the UK at the beginning of the Neolithic.
The "archer's" Beaker people all but replaced the earlier farmer culture. Neolithic farmers migrating into Mesolithic Britain (c. 4200 BC) had dark hair, intermediate brown skin and brown eyes. They were replaced following the Beaker migration, by people of lighter skin, blue eyes and blonde hair which became commonplace in the UK with the Beaker people. The original (Mesolithic) hunter gathers in the UK had dark hair, dark or black skin and blue eyes; e.g. "Cheddar Man".
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| 18 April 2019 Springbank |
