Saturday, February 14, 2015

Evaluating Population Genetics Papers

Many people don’t know how to evaluate population genetics articles, because they are expost facto research based on “ statistical infererences” or the beliefs of the researcher  supported by statistics. As a result, researchers can not judge the difference between an ad hominid and legitimate discussion of the doxa behind a researcher’s research.

In traditional evaluation of a piece of research literature  you look at the researcher's hypothesis, results and statistical methods s/he used to determine the statistical significance of the research.This is not the case in population genetics research; in this research you are evaluating statistical inferences based on the researchers beliefs about a set of data, instead of testing a hypothesis. As a result, the research contained in a population genetics article, reflects the views and beliefs already held by the researcher. Thusly, the statistical inferences will automatically support the views and beliefs held by the researcher; and any outliners that fail to support the researchers  beliefs will not be mentioned in the research article/paper.

 Here we will ask the question: “How do you evaluate population genetics research?” We will attempt to look at the doxa that may influence a geneticist's research and the constructs that should be considered when evaluating this knowledge base.

    Firstly, we assume that any article or book written by an establishment member of the academe is reliable and valid. A piece of research full of  valid  scientific and/or historical truths--erudite scholarship and impeccable research based on the scientific method.

 The scientific method is based on hypotheses testing. Hypotheses testing means that a researcher forms a hypothesis and test the hypothesis using a series of quantitative or qualitative statistical methods to determine the statistical significance of the hypothesis being tested. The scientific method  is based on experimentation to test a hypothesis .

Population geneticists usually do not test hypotheses. They make inferences about data based on Bayesian statistical inferences. They do not use statistical methods to determine the statistical significance of a hypothesis, they use statistics to describe data being reviewed by the researcher based on the beliefs the researcher already holds about the data being reviewed..

Population genetics is a type of  Expost facto research. Expost facto research design is a quasi-experimental type of study examining how an independent variable, present prior to the research study,  affects a dependent variable.

Whereas the subjects in experimental research are randomly selected,  the participants in Expost facto research , are not randomly selected or assigned.The genome of the research subjects is examined to determine the haplotypes and haplogroups carried by the participants in the study.

In population genetics research the researcher uses the Bayesian inference method of statistical inference. Bayesian statistical method, is a subjective research design/method that provides a rational method of updating the researcher's beliefs.

 Since, the results of a Bayesian statistical analysis are a series of beliefs based on statistical inferences, the results can not stand alone. This is due to the reality, that any results, reported by a researcher are only a series of inferences based on the researcher’s belief about a phenomena backed up by a series statistical results. If the results are published without corresponding evidence from archaeology, anthropology, linguistics and or craniometrics the inferences are pure conjecture, because they reflect the attitudes already held by the researcher, confirmed by data selected by the researcher to support his or her beliefs.

There is a sociological  basis behind how a researcher interprets data. Sociological research indicates that there are unconscious cognitive structures within each individual. Cognitive structures that  hold the idealistic view of members of the academe that determine how they perceive "reality". These structures are called doxa.

 Commenting on these schema Berlinerblau (1999) noted that "These types of theories share the assumption that human beings know things that they do not even know that they know; that they "possess" knowledge about the world which exists in some sort of cognitive substrate, beyond the realm of discourse" (p.106).Wacquant (1995) says that doxa is " a realm of implicit and unstated beliefs".

      Given the research suggesting that doxa exist, support the view that some researchers allow their hatred of multiculturalism, ethnic prejudice and racism to define their discourse, teaching and writing about themes relating to groups " other" ,than their own cultural and ethnic group . Moreover, it suggest that when topics such as Eurasian and African haplogroups, Afrocentrism, African origins of the Dravidians and etc., is attacked by members of the academe, these academics are supported by the "establishment" without any reservation, or test of the validity of their claims. In fact, it appears that doxic assumptions relating to the validity of Afrocentrism, back migration of so-called Eurasian genes into Africa, rcent African origens of Dravidians and Dravidian origin of the Indus Valley Civilization obviates critique of the academics that disparage these themes. Due to Doxa you can state a researcher’s attitude toward a historical, genetic or anthropological concept and theorems without the statement being an  ad hominem

To evaluate  research literature a student should know the varied research methods.A student  evaluating a piece of population genetics’ literature must understand that the researcher is conducting an expost facto method of research that does not involve hypotheses testing .Given the nature of Bayesian inferences, you can not determine the validity and reliability of a piece of genetics  research literature based on the statistical significance of the data. What you must do is look at the research article and ask yourself a series of questions regarding the article's validity and reliability. Below is a series of questions to evaluate population genetics articles.

                   Checklist used to analyze a Population Genetics Papers

Answer the following questions relating to this research article  below, or on a separate sheet of paper.

1.            What was the rationale for the study, that is, what led up to it?
Yes on page___ ,paragraph____ _,lines________ No_______
2.            Why do the authors believe that this problem is significant? Yes on page___ ,paragraph____ _,lines________ No_______
3.            What was the purpose of the study, that is , what did it intend to accomplish?
Yes on page___ ,paragraph____ _,lines________ No_______
4.            What was the hypothesis of the study?
Yes on page___ ,paragraph____ _,lines________ No_______
5.            What were the participants major characteristics?
Yes on page___ ,paragraph____ _,lines________ No_______
6.            Does the review of literature indicate previous research in the area associated with the article?
Yes on page___ ,paragraph____ _,lines________ No_______
7.            What type of study is reported in this article?
Yes on page___ ,paragraph____ _,lines________ No_______
8.            Was the sample randomly selected?
Yes on page___ ,paragraph____ _,lines________ No_______
9.            What was the instrument?
Yes on page___ ,paragraph____ _,lines________ No_______
10.          What were the major steps involved in the treatment?
Yes on page___ ,paragraph____ _,lines________ No_______
11.          How were the variables tested?
Yes on page___ ,paragraph____ _,lines________ No_______
12.          According to the author(s) how successful was the treatment?
Yes on page___ ,paragraph____ _,lines________ No_______
13.          What factors could equally account for the student tests results?
Yes on page___ ,paragraph____ _,lines________ No_______
14.          What problems, if any, do you detect in the study?
Yes on page___ ,paragraph____ _,lines________ No_______

15.          Do the results of analysis agree with the authors objectives and expectations?
Yes on page___ ,paragraph____ _,lines________ No_______

16.          What other interpretations could  be made from the data?
Yes on page___ ,paragraph____ _,lines________ No_______

17.          Is there archaeological, craniometric and or linguistic evidence that  supports the research findings
Yes on page___ ,paragraph____ _,lines________ No_______

The Evaluator should read the article twice. The first reading of the article is brief.

Next make a close reading of the article. The close read should involve the Evaluator in underlining key details in the article, while making annotations of important points in  the text. During the second reading of the text the Evaluator will assess the research article using the checklist above.Since the Bayesian statistics used for the study will support the inferences of the Researcher the answers for the majority of the checklist will be yes.

The key question in determining the validity of the research will be question 17. If the researcher only has Bayesian statistical inferences supporting the research study , the inferences made in the research article , may not be representative of actual past population events.

In summary, the validity and reliability of a piece of genetics research literature does not demand the Evaluator of a piece of literature to provide counter evidence all they need to do is evaluate the research using the checklist above. If the answer to most of these questions is no, the research is unreliable and lacks any validity.

The key question on the checklist is question 17. To confirm the validity of the archaeological, craniometric and etc., data , the Evaluator should be knowledgeable about the archaeology of the area where the population movement has been inferred to have taken place.In this way you can determine if the  Bayesian inferences correspond to the archaeological, craniometric, linguistic data associated with the geographical area where the population movement is suppose to have occur .

The major problem with most genetics literature which invalidates the research dealing with ancient population movements is that it is not supported by the ancientDNA, archaeological and/ or craniometric data. This is why many of theories about the ancient populations of Europe and alledged back migrations are usually over turned once researchers examine the ancientDNA.

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