Anthropology through microscope


Last week we discussed the origins, importance, and the latest trends of anthropology – in particular, digital anthropology. Anthropology is a vast vista of knowledge and thus has a plethora of sub fields of studies all of which cannot possibly be covered comprehensively in a single article. Therefore, as a continuation to the previous week’s article and as a possible series of articles, Ceylon Today hopes to familiarise you, in the coming weeks, with the ‘science of people’ or the vast area of study that is anthropology. 

Another sub area of study in anthropology is molecular anthropology which is a newly-developed and advanced field of studies that contributes to the sublime stream of anthropology with modern technology and science. This field, which comes under the physical anthropology, fundamentally focuses on the molecular patterns of the human body and attempts to decipher the related cultural aspects too. So, continuing the series of articles, the Department of Anthropology of University of Sri Jayewardenepura shared knowledge in this regard with Ceylon Today.

Senior Lecturer at the The Open University of Sri Lanka, Dr. Ruwan J. Illeperuma who also works as a visiting lecturer at the University of Sri Jayewardenepura, briefing the subject, elaborated on what molecular anthropology is;

“As we already know anthropology is a vast field of studies which investigates humans, or us. Molecular anthropology is a much specialised, unique sub-field that comes under anthropology. Unlike in the other classical subjects of anthropology, in molecular anthropology the human is perceived from a different perspective; from a molecular level. Molecular anthropology looks at the essential chemical, deoxyribonucleic acid (DNA), which is very important for the sustaining of life on earth.

“In anthropology we try to find answers for three main questions; the origin of the humans (when, where, and how), how did the evolution of the humans from that point up to the present occur, and how the humans would further evolve into the future. Nonetheless, we haven’t witnessed any of these events. Therefore, we try to understand them in anthropological terms or in relevance to the inferences. For an instance, in archaeology-which is also a sub field of anthropology-we make assumptions based on the various artefacts and such other remains from the past and still exist at present. So, likewise in molecular anthropology, we also look for evidences or clues to make inferences on the origin, evolution and the future of the mankind. That evidence used in molecular anthropology is none other than human DNA. These DNA molecules have existed in the human bodies since thousands of years and still exist. They have been shared, or inherited through many generations throughout the history. So this study is what, basically, molecular anthropology is”

DNA, the library of genetic information

“DNA plays a very vital role in a human body. They store all the information about the physical and behavioural characteristics of an individual. Therefore, in molecular anthropology, our prime evidence or the artefact to dig deep into the history is this DNA molecule” Dr. Illeperuma explained.

“DNA is basically found in two places within the human cell, which actually is the fundamental building unit of the human body. The chromosomal DNA is found in the nucleus of the cell as 23 pairs of chromosomes. The circular chromosomes found outside the nucleus, inside the cellular organelles called mitochondria, are known as the mitochondrial DNA. These two types of DNA are very specific and provide us with two unique perspectives to look at an individual when it comes to anthropology. The mitochondrial DNA stores the genetic information received exclusively from the maternal side. So, by studying those, we can decipher back into as many as hundreds of generations from the mother to the grandmother to the great grandmother and so on. That is one DNA marker used in molecular anthropology.

“When it comes to chromosomal DNA, there are 23 pairs of chromosomes, out of which one pair is the sex chromosome. A female has two X chromosomes (XX) coming from the mother, and a male has an X chromosome coming from the mother and a Y chromosome (XY) coming from the father. By studying the Y chromosome of a male individual, we can trace back his paternal lineage up to many generations back. This is the second DNA marker.

“The third DNA marker is based upon the non-sex chromosomes or the remaining 22 pairs of chromosomes. These chromosomes store genetic information received from the sides of both parents. Thus, they give out a holistic insight into both lineages.  So, as we discussed, these three panels of DNA markers give out information about ‘us’ in three uniquely different angles and those three perspectives, in cohesion, helps to trace back very deep into the past of humans. Indeed, at one point, we can trace the genetic information of the primitive ancestors of humankind also, and answer to the questions regarding the origin of the humans.

“In the same token, DNA has stored information about the changes that has taken place in them over the time too. So, as anthropologists we study that information, analyse them and infer about the evolutionary process of the humans.  In the same way, we can utilise the aforementioned information to identify the evolutionary patterns and based upon that knowledge we can assume how we would evolve into the future. So, with the molecular anthropological studies, it is not much difficult to guess how the humans would be in another hundred or two hundred years of time.” he explained in detail.

Indeed, it is really interesting how all three main questions of anthropology are answered just with the help of a tiny DNA molecule. The applications of this science would make greater changes on the future of our whole society.

Molecular studies in anthropology

Molecular anthropology is used in a vast array of subject and professional fields for various identification and inference purposes.  The DNA analyses of molecular biology are highly used in the health sector nowadays. Speaking of that, Dr. Illeperuma shared with Ceylon Today, how these studies contribute to decipher different diseases and disorders that affect humans and other important animals as well. “DNA analyses are being used for diagnosis purposes, in medicine. Worldwide, DNA testing is widely used to identify infectious diseases; the pathogens (a bacterium, virus, or other microorganisms that can cause disease) actually. So, we can learn how a particular disease develops, spreads and how it should be cured through molecular approaches and implement ways and means to cure the infected as well as to discontinue the spreading of it.

“Not only in identifying contagious diseases, this DNA technology can be utilised in diagnosing and treating non-transmittable disorders such as Down’s syndrome and thalassemia. They are not infected from a person to person, but are inherited. So, by using the molecular technology, it can be identified how the genes accountable for those diseases develop and function. Then, it is possible to search for cures to those diseases.”

Add to that, this study helps to study various individuals exclusively and identify the reasons behind their behavioural patterns and assist them if there’s any abnormity. Identifying the behaviour is also very significant in comprehending several sociological issues too.

Molecular anthropologists in forensic investigations

Speaking further, Dr. Illeperuma explained how the molecular anthropological techniques are applied in DNA-based forensic investigations also. Forensic scientists use DNA profiles to identify criminals or determine parentage as it is like a genetic fingerprint; every person has a unique DNA profile, making it very useful for identifying people involved in a crime.

“In fact, molecular anthropology and DNA based forensic investigations are two different fields and do not totally and necessarily overlap.  Molecular anthropology focuses on studying the past or the future, based upon the inferences generated by DNA analyses, but DNA testing in forensic science is carried out to distinguish an individual from the mass of people. Nevertheless, there are some instances where the study techniques of molecular anthropology contribute in these forensic investigations too.

“Say for an example that a Police Officer has discovered a hair shaft from a place where a crime had taken place. Then, a DNA test is carried out, to see if it matches with the DNA of any of the suspects. Though, with the aid of molecular anthropological knowledge, it can be distinguished whether the criminal is a male or a female and narrow down the list of suspects. It can be further narrowed down by determining other anthropological aspects of that person such as ethnicity; whether that person is Sinhalese or Muslim or Tamil. There are unique features in the DNA which can be separately identified from one ethnicity to another. Likewise, the Police can narrow it down to a very low number of suspects and spot out the criminal with less effort, thanks to the molecular anthropological applications”

A tool to cross-check the history

According to Dr. Illeperuma, molecular anthropology is a great device that fact checks the different and contrasting historical records and various beliefs. “As we know, there are various interpretations of the history and origin of nations and other stories. These contrasting ideas often lead to conflicts and even to violence. There are enough and more examples from the history for that. However, with the help of molecular anthropology we can fact-check those opinions and check what is correct and what is wrong.

For an example, we believe that the Sinhalese nation continues from the King Vijaya, and the Vedda community is the continuation of Kuveni’s people, who have originally inhabited the Island. So, if this is true, the male-specific genes of the Sinhalese should match the genes of the North Indians because King Vijaya’s ancestors were from Sinhapura, in North India. Hence, we can check the validity of these stories very easily with anthropological approaches with the help of molecular science,” he elucidated. Likewise, the Kuveni’s descent can also be reached through the Mitochondrial DNA of present-day living Vedda community.

Finally, the Department of Anthropology of University of Sri Jayewardenepura invites all the students of anthropology and other stakeholders to join with them through the official Facebook page Anthropology crew of University of Sri Jayewardenepura or the university website, since there will be many events and programmes regarding the subject in future.

By Induwara Athapattu