Quick Tips: Archaeological Techniques –Use of Isotopes in Archaeology.

Isotopic analysis is widely used within the worlds of archaeology and anthropology. From analysing isotopes we’re able to uncover a wide range of information regarding the past; ranging from palaeoenvironments to palaeodiets, and even using isotopes to reconstruct trade routes of materials.

But first, what are isotopes?

All of the chemical elements consist of atoms which are specific to the element and the mass of an atom is dictated by the number of protons and neutrons it contains. The identity of the chemical element depends on the number of protons found within the atom’s nucleus, but the number of neutrons within the atom can vary. Atoms of the same chemical element (same number of protons), but with different masses, which is from the varying amount of neutrons, are called isotopes.

Stone Circle at Drombeg

Within nature, most of the elements consist of a number of isotopes. These isotopes can be found within water, livestock, crops and plants, which can then be used to reconstruct palaeodiets and palaeoenvironments.

Within nature, most of the elements consist of a number of isotopes. For a great majority of elements these relative proportions of isotopes are fixed, but there are a group of elements which either due to chemical or biochemical processes are of variable isotopic composition. These elements are oxygen, carbon, nitrogen and sulphur. Another group of isotopes that are used for analysis are strontium, lead and neodymium. These are formed by elements which contain stable but radiogenic isotopes, which are formed by radioactive decay of another element. Carbon and nitrogen isotope composition are primarily used to reconstruct diets, and oxygen isotopes are used to determine geographic origin. Strontium and lead isotopes found within teeth and bone can sometimes be used to reconstruct migration patterns in human populations and cultural affinity

Isotopes Table

A table of the various elemental isotopes that are valuable in archaeological and anthropological research.

But how do isotopes get into skeletal remains?

Carbon isotopes are taken up through the diet of animals during their lifetime and these isotopes are deposited into teeth and bones of humans when they are consumed and digested. By studying animal bones and examining the 12C and 13C isotope ratio, it is possible to determine whether the animals ate predominately 3C or 4C plants. Oxygen isotopes are constantly being taken up and deposited into the body through the water a population drinks. This process ends with the organism’s death, from this point on isotopes no longer accumulate in the body, but do undergo degradation. For best result the researcher would need to know the original levels, or estimation thereof, of isotopes in the organism at the time of its death.

By creating a map of these natural occurring isotopes in different environments, rivers and areas, it is possible to identify where in an area the population lived, sourced their water or where the livestock grazed, by comparing the levels of isotopes that were obtained from skeletal remains to the environmental map. This mapping can also help identify trade routes that once existed and can also identify the migration patterns of populations.

References:

Balme, J., Paterson, A. 2006. Archaeology in Practice: A Student Guide to Archaeological Analayses. Oxford, UK: Blackwell Publishing. Pg 218.

Renfrew, C., Bahn, P. 1991. Archaeology: Theories, Methods and Practice. London, UK: Thames & Hudson. Pg 249-53.

If you’re new to the realm of archaeological, anthropological and forensic sciences (AAFS), or are a student needing sturdy and reliable references, or wondering “what archaeology or anthropology textbooks to buy? Check out our new ‘Useful Literature’ page!

Useful Literature.

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If you’re new to the realm of archaeological, anthropological and forensic sciences (AAFS), or are a student needing sturdy and reliable references, or wondering “what archaeology or anthropology textbooks to buy?”
On our ‘Useful Literature’ page you can find links to the full selection of the best textbooks – most of these have been suggested to me by my university Professors.

Here is a short-list of the most helpful student books for archaeology and anthropology:

Quick Tips: Forensic Entomology – An Introduction.

What is forensic entomology? It is a discipline within forensic sciences where specialists use information that they know about insect lifecycles and behaviours to interpret evidence in a legal context, relating to humans and animals. Entomologists don’t just stick to insects; their work can expand to include other arthropods, mites, spiders and macro-invertebrates.

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Insect species which are relevant to forensic entomology

What information can we learn from insect activity? Insects are everywhere and can hardly be avoided, so it’s no surprise that sometimes they get mixed up in the evidence left behind – making them extremely valuable to an investigation. Insects can be a vital part of forensic science as they can provide a time and date to a crime or even a geographical position to where it happened. As some insects only become apparent during certain months, they can become a biological calendar for when a crime might have been committed. As well as being a biological calendar, certain insect species are only native in specific countries or hemispheres. This can be used to create an ‘X marks the spot’ on where a crime was committed – even if a body was moved/buried. Because of this, insects can be the key to past and present events as well as the future.

The insects that are particularly relevant to forensic entomological investigations are blow flies (diptera), flesh flies, cheese skippers, hide and skin beetles, rove beetles and clown beetles. These forensically relevant insects can be placed in four categories:

  • Necrophages, which feed only on the decomposing tissue of the body or body parts. This is the category that blow flies, hide beetles and clown beetles are classed under.
  • Predators of the necrophages – for example the rove beetles and ground beetles.
  • Omnivores that consume both the live insects inhabiting the corpse and the dead flesh – ants and wasps.
  • Opportunist species, which arrive because the corpse is a part of their local environment. This is where mites, hoverflies, butterflies and occasionally spiders are classified.

Forensic entomologists use the evidence they gain from studying insects within legal cases in either civil or criminal courts. Civil court cases include:

  • Insect infestation in urban contexts.
  • Stored product infestations/pests.

Criminal court cases include:

  • Neglect – either animal or human (elderly and children).
  • Insect infestation of a body – living or dead.
  • Death in which foul play is suspected.

This is just an introduction into the world of forensic entomology, if you’d like to know more or further your knowledge on this topic check out this book, I found it very interesting and a terrific read:

  • Forensic Entomology: An Introduction (UK/Europe)
    Forensic Entomology: An Introduction (US/Worldwide Link)
    by Dorothy Gennard. Rating – ***
    “I used my this for my blog post on the basics of forensic entomology. It is perfect if you’re unsure on whether or not you want to pursue this career/discipline. Definitely a good read if your interest is sparked by Dr Hodgins from ‘Bones’, as it explained everything involved within entomology under legal settings.”

Unusual-ology: Male Spiders Self Sacrifice for Better Offspring.

Unusual-ology is a new post type which focuses on weird new articles/science areas that have cropped up and caught my eye.

The practice of monogyny is found throughout the insect kingdom, especially arachnids. One such arachnid is the make dark fishing spider (Dolomedes tenebrosus). A recent study in Biology Letters has discovered that the male arachnid willingly sacrifices itself to the female to ensure that the resulting offspring is healthy; by providing itself as a meal for the female.

Video of the mating rituals and cannibalism from the experiment – Royal Society of Journals

Schwartz et al (2013) think that this practice of sexual cannibalism may provide an ‘evolutionary advantage’, because a better fed female is more likely to provide healthy descendants. But there are certain drawbacks to this practice; if a male dark fishing spider accidentally prematurely triggers one of their pedipalps, their two feeler-like appendages near the mouth where sperm is stored, they can die. Schwartz has encountered many problems during his experiment while catching the wild male specimens; they would accidentally snag their pedipalps on a piece of cotton which would cause them to die before the experiment could take place.

References:

National Geographic. 2013. Male Spiders Self-Sacrifice, Lose Genitals. National Geographic News. Click here for the article.

Schwartz, S.K., Wagner Jr, W.E., Hebets, E., A. 2013. Spontaneous male death and monogyny in the dark fishing spider. Biology Letters. 9, 4. Click here for the journal.

If you’ve enjoyed this new ‘Unsual-ology’ post feature – leave a comment or a like!

If you want to read more unusual science posts click here, or to read the Unusual-ology post on the Ancient Egyptian use of lettuce as an aphrodisiac, click here. Or to read about the newly discovered ‘Entrance to Hell’ click here!

Quick Tips: The Use of 3D Animation to Visualise a Crime Scene in Forensics.

Many television programs create 3D animations and computer generated images using highly technical computer programmes to help re-enact the scenes or time frame of a crime. This is mostly used so that the viewer at home can really grasp what crime has been committed and help establish a sense that they are a witness. But in reality these animations and images are becoming an increasingly popular technique used within the courtroom.

Information and evidence can be easily constructed from the traditional methods of forensic photography, blood spatter analysis and eye witness testimonies. But in this modern technological time the information gathered is now being used to create computerised animation that depicts the series of events within a crime. But is this method of providing visual appropriate and correct? Could the animation be showing a display of actions/movements that humans can’t possibly and physically make?

There is a big issue with admissibility, which can cause bias. This occurs when the jurors or judge aren’t aware of an error/uncertainty within the procedure of recreating a real life scene into animation. This can cause them to believe that the evidence is a hundred per cent correct, when in fact there are many errors which were created in the process or animation (Ma & Zheng, 2010). Another big problem arises when studies found that people are five times more likely to remember something they see and hear rather than hearing alone. People are also twice as likely to be persuaded if the arguments are backed with visual evidence (Lederer & Solomon, 1997). So this poses a huge problem as false memories and false testimonies could be influenced, which in the end could cause an innocent person to go to jail for a crime they did not commit.

So with the possibility of creating false memories is the use of 3D animation beneficial for the use of visualising crime scenes within court? It is argued that it is as the use of computerised images creates a higher level of accuracy and speeds up the forensic investigational process but only in major crime types, not every day homicides and robberies. However even though it has limited application in the courtrooms,  it can pose to be very useful in formal briefs with the forensic personnel, and within the backstage elements of the investigation itself (Ma & Zheng, 2010).

References:

Lederer FI, Solomon SH. 1997. Courtroom technology – an introduction to the onrushing future. Fifth National Court Technology Conference: National Centre for State Courts. Available here.

Ma M, Zheng H. 2010. Virtual Reality and 3D Animation in Forensic Visualization. Journal of Forensic Sciences. 55, 5. 1227-1231.

New Evidence Supports Conflict is Not Innate.

In a previous post – which can be found by clicking here – I had examined whether conflict was innate for humans after a lecture in University, which I concluded was true by analysing different theories but stressed that conflict only becomes active due to a stimulus. That stimulus could either be biological, seen in aggressive mating, or environmental, such as intraspecific/intrespecific competition. But a recent study, noticed by the BBC has put a spanner in the works, as the leading researcher – Patrik Soderberg – says that conflict isn’t actually innate.

Soderberg’s research based its findings by studying isolated tribes from numerous places around the world which had been studied over the last century. By using modern primitive isolated tribes they were able to have a sample which was cut off from the modern day life and utilising the wild plants and animals that inhibit their environment, surviving like the much older hunter-gatherers.

Ancient hunter-gatherer cave art.

Ancient hunter-gatherer cave art.

Using these modern day tribes as an analogy for the earlier societies that ruled the lands, they assessed and analysed any violent deaths. They found that in their sample populations there were 148 violent deaths, but very few were caused by widespread war. Most of the violent deaths were caused by personal motives ranging from family feuds or adultery.

Soderberg has admitted that these modern tribes were not a ‘perfect model’ for the ancient civilisations but said that due to vast significant similarities they did allow for an insight into the past. From this study he concluded that war may have developed later as the hunter gathers became more agriculture orientated and territorial with a complex social structure. “As humans settled down, then war becomes more dominant and present. For these primitive societies, war has not yet entered the picture,”.

References:

BBC. 2013. Primitive human society ‘not driven by war’. BBC News. Available here.

Soderberg, P., Fry, D. 2013. Latest Skirmish Over Ancestral Violence Strikes Blow for Peace. Science. 341, 6143. P224. Here is a link to view the .pdf of this very interesting article.

Tsunami in Japan claims lives of many endangered species.

The recent 2011 tsunami and earthquake in Japan delivered mass destruction across the Japanese mainland and notably the capital Tokyo. The tsunami claimed many lives of the population residing on the coast and caused millions of pounds worth of damaged.

A recent BBC (2011a) news story has highlighted that humans were not the only species of animal affected by this natural disaster. Thousands of albatrosses were killed when the destructive waves hit a wildlife sanctuary north-west of Hawaii. The sanctuary based on the Midway Island, which is the home of the vulnerable Laysan albatross (Phoebastria immutabilis), was first created after US Naval Air facility was shut down in 1993.

The US Fish and Wildlife Service reported that 1,000 adult and adolescent Laysan albatross were killed when the 1.5metre high waves hit the National Wildlife Refuge (NWR). Along with the 1,000 adults approximately tens of thousands of chicks were killed when nearly 60% of the island was covered by the huge waves.

The Laysan albatross weren’t the only species of animals that was damaged by the effects of the tsunami. The population of Bonin petrels (Pterodroma hypoleuca) took a damaging blow when they were buried alive. Bonin petrels are ground nesting so live in burrows underground so scientists are uncertain about how many were affected. Scientists at the NWR were hoping that they were out foraging for food as they feed at night when the tsunami’s waves washed over the island at dawn (Yahoo, 2011). The impact of the tsunami on other species such as the Laysan ducks and monk seals are currently unknown by wildlife conservationists (BBC, 2011a).

Along the survivors of the killer waves was a 60 year old Laysan albatross named Wisdom who recently hit the news headlines as the ‘Oldest bird in the US’ after she was found mothering a chick (NYTimes, 2011). The US Geological Survey (USGS) first ring tagged Wisdom in 1956 when she was incubating an egg. It is estimated that over the past 54 years she has mothered over 30-35 chicks (BBC, 2011b).

This demonstrations that natural disasters not only damage the human race but they also put other species, which are already close to being endangered, even closer to extinction.

References:

BBC. 2011a. Japan tsunami: Thousands of seabirds killed near Hawaii. BBC News.

BBC. 2011b. ‘Oldest bird in US’ raises chick. BBC News.

NYTimes. 2011. Albatross Is a Mother at 60. The New York Times.

Yahoo. 2011. Tsunami killed thousands of seabirds at Midway. Yahoo News.