Substructuring in four populations of African descent

Authors

Margarita Teresa Almeida, Florida International University

Document Type

Thesis

Degree

Master of Science (MS)

Major/Program

Biology

First Advisor's Name

Martin L Tracey

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

Arni Masibay

Third Advisor's Name

Rene J. Herrera

Fourth Advisor's Name

Case K. Okubo

Date of Defense

7-24-1997

Abstract

When a suspect's DNA profile is admitted into court as a match to evidence the probability of the perpetrator being another individual must be calculated from database allele frequencies. The two methods used for this calculation are phenotypic frequency and likelihood ratio. Neither of these calculations takes into account substructuring within populations. In these substructured populations the frequency of homozygotes increases and that of heterozygotes usually decreases. The departure from Hardy- Weinberg expectation in a sample population can be estimated using Sewall Wright's F_st statistic. F_st values were calculated in four populations of African descent by comparing allele frequencies at three short tandem repeat loci. This was done by amplifying the three loci in each sample using the Polymerase Chain Reaction and separating these fragments using polyacrylamide gel electrophoresis. The gels were then silver stained and autoradiograms taken, from which allele frequencies were estimated. F_st values averaged 0.007+- 0.005 within populations of African descent and 0.02+- 0.01 between white and black populations.

Identifier

FI13101597

Recommended Citation

Almeida, Margarita Teresa, "Substructuring in four populations of African descent" (1997). FIU Electronic Theses and Dissertations. 1073.
https://digitalcommons.fiu.edu/etd/1073