Ranajit Chakraborty

Ranajit Chakraborty was born in Baranagore (West Bengal), India. At his graduation from high school in 1963, he was awarded First Class with Distinction Certificate from the Board of Secondary Education of West Bengal. In 1967, got his Bachelor of Statistics degree (with honors) from the Indian Statistical Institute, Calcutta, and a year later was awarded a Master of Statistics (with specialization in Mathematical Genetics and Advanced Probability). In 1971, he got his Ph.D. in Biostatistics from the Indian Statistical Institute.^[1] His dissertation supervisor was C. R. Rao, FRS. Before obtaining his first tenure-track academic position, Chakraborty served as Research Scholar and Senior Research Fellow at the Indian Statistical Institute, Visiting Lecturer of Statistics at the Indian Institute of Management, and Visiting Consultant at the Data Reference Center of the World Health Organization at the University of Hawaii in Honolulu.

In 1973, Chakraborty joined the faculty at the Center for Demographic and Population Genetics, which is now the Human Genetics Center, at the University of Texas Health Science Center at Houston. From 1996 to 2001, he held the Allan King Professorship at the School of Public Health. In 2001, he became the Robert A. Kehoe Professor and Director of the Center for Genome Information at the University of Cincinnati Medical Center in Cincinnati, Ohio. In 2009, Chakraborty joined the Department of Forensic and Investigative Genetics, University of North Texas Health Science Center, Fort Worth, Texas.

In addition to his main academic appointments, throughout his career, Chakraborty served in various capacities on the faculties of University of Houston, Stanford University, Stockholm University, University of Michigan, Rice University, and Universidad de Chile.

Ranajit Chakraborty wrote six books and over 600 scientific articles.^[2][3][4] Three of these became citation classics.^[5]

Chakraborty's research contributions were in three main areas. During the first phase of his professional career, he contributed to the development of population genetics and molecular evolution. In collaboration with Masatoshi Nei, Takeo Maruyama, and Paul Fuerst, he studied among others the effects of bottlenecks on genetic variability,^[3] the distributions of allele frequencies,^[6] and the distribution of single locus heterozygosity.^[7] He also contributed to the development of the two main mutation models in population genetics: the infinite alleles model^[8] and the stepwise mutation model.^[9] Ranajit Chakraborty made a large number of methodological contributions to population genetics, such as the use of the number of rare alleles per locus to estimate mutation rates.^[10]

The second area to which he made significant contributions was human genetics and human epidemiology. Among others, he studied the effects of consanguinity and consanguineous marriages on genetic load,^[11] the genetics of obesity,^[12] gallbladder disease,^[13] and type II diabetes.^[14]

His third area of research interest was forensic genetics, i.e., the use of DNA data and genetic methodology in the process of individual identification initially in criminal and civil cases, and later in determining ethnic ancestry and relationships. One of Dr. Chakraborty's main contributions to the methodology of identification by DNA data concerned the selection of control groups for ruling out errors in identification and for calculating precise probabilities of the two types of errors (false positives and false negatives). He also contributed to the study of microbial forensics, i.e., the rapid identification of bacterial agents used in bioterrorism and biocrimes.^[15]

In 1991, Ranajit Chakraborty and Kenneth Kidd published one of the first articles on the utility of DNA data in forensics.^[16] The importance of this paper in the rapid adoption of DNA-based methods by the legal system has been frequently commented upon.^[17]