Review Questions

8.1. Four microsatellite loci were used to genotype black bears from three Canadian National parks: Banff in Alberta (B), La Mauricie in Quebec (LM), and Terra Nova in Newfoundland (TN) (Paetkau and Strobeck, 1994). The results of this study are shown in Table 8.5.

Table 8.5 Some of the results from a microsatellite-based study of black bears from three Canadian National parks

Park

Expected heterozygosity

Total number of alleles

Probability of identity

B

0.801

32

1.1 x 10~5

LM

0.783

35

2.2 x 10~5

TN

0.360

9

4.6 x 10~2

Are these microsatellite loci sufficiently variable to allow for individual genetic identification in cases of poaching? In answering this question, refer to the average number of individuals in each population that would need to be sampled before duplicate genotypes were found. Why do these markers provide greater resolution in some populations compared with others?

8.2. The mutilated flesh of an unknown animal was sent to a laboratory for species identification. Biologists there used universal primers to amplify and sequence part of the mitochondrial cytochrome b gene. Part of this sequence was:

AGGAGCAACA GTCATTACCA ACCTTCTCTC AGCAATTCCA TATATTGGTA CAAATCTAGT CGAATGGATC TGAGGGGGCT TTTCAGTAGA TAAAGCAACC

Go to the National Center for Biotechnology Information (NCBI) website (http:// www.ncbi.nlm.nih.gov/) and click on the BLAST option on the horizontal bar immediately below the page title. Under the nucleotide heading, click on the Nucleotide-nucleotide BLAST (blastn) option. Enter this sequence into the box and then click on the Blast button. You will see a list of alignments, the first of which has the closest match to your sequence. What species does this mutilated carcass belong to?

8.3. The boll weevil Anthonomus grandis) has been the most destructive pest of cotton in the USA since it invaded that country around 100 years ago. RAPD markers were used to study gene flow and dispersal patterns among boll weevils in the south-central Cotton Belt of the USA and northeast Mexico (Kim and Sappington, 2004). Weevils were genotyped from 18 populations distributed among three geographical regions. Genetic diversity was highest in Mexico and lowest towards the northern limit of the boll weevil's geographical range. The Nm estimates (derived from FST values) suggest that gene flow is relatively frequent within regions (populations separated by up to 500 km) but much more limited between regions. What do these patterns suggest to you about the colonization and subsequent dispersal of the boll weevil in the USA?

8.4. Why might the stocking of wild fish populations with hatchery-reared fish reduce the overall Ne/Nc ratio?

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