SCI 130 Lab 7 CSI Wildlife Case 1 General Instructions

Scin 130 Lab 7 Csi Wildlife Case 1general Instructionsbe Sure To Rea

Read the general instructions from the Lessons portion of the class prior to completing this packet. Remember, you are to upload this packet with your quiz for the week. The scenarios investigated are based on recent literature: Wasser, S. K., Brown, L., Mailand, C., Mondol, S., Clark, W., Laurie, C., & Weir, B. S. (2015). Genetic assignment of large seizures of elephant ivory reveals Africa’s major poaching hotspots. Science, 349(6243), 84–87. The underlying data are available on the Dryad Digital Repository. DNA is made up of nucleotides; an allele is an alternative form of a gene, found at the same locus on homologous chromosomes, and may result from mutation. Review these terms in your textbook if unfamiliar.

Paper For Above instruction

The purpose of this laboratory exercise is to investigate the application of DNA profiling in wildlife conservation, specifically focusing on elephant ivory poaching and the use of genetic assignment to identify poaching hotspots. The lab tasks are based on a real-world study by Wasser et al. (2015), which used genetic data to trace ivory seizures back to geographic regions in Africa, enhancing conservation efforts by pinpointing poaching hotspots.

Understanding DNA and genetic markers is central to this process. DNA consists of nucleotides, and individual genetic variations, such as alleles, help differentiate between individual animals and populations. DNA profiling, also known as DNA fingerprinting, involves analyzing specific regions of DNA—particularly short tandem repeats (STRs)—to generate a unique genetic profile for each animal. These profiles are visualized through gel electrophoresis, which separates DNA fragments based on size. The resulting band patterns serve as a genetic “signature” that can be compared across samples to identify matches or differences.

The experiment begins with an introduction to the concept of keystone species and its relevance to ecological stability. Dr. Wasser’s research utilizes genetic data from seized ivory to determine the geographic origins of the elephants involved, thereby informing conservation strategies aimed at mitigating poaching activities. The location of the majority of African elephants, the primary focus for genetic analysis, is predominantly in protected reserves and regions with dense forest cover, which complicates direct observation but is accessible via genetic tools.

The section on DNA profiling techniques highlights the importance of STRs, which are highly polymorphic and thus ideal for individual identification. Bands on an agarose gel represent DNA fragments of varying sizes, with each band corresponding to a specific allele at a particular locus. The DNA ladder—an essential reference—provides known fragment sizes that allow for precise size estimation of unknown samples. Despite some misconceptions, DNA fingerprinting is not akin to human fingerprints; however, both patterns (bands and ridges) are unique to individuals, allowing for identification.

Sources of elephant DNA include blood, tissue samples, dung, and ivory fragments, which provide the genetic material necessary for analysis. The Polymerase Chain Reaction (PCR) is employed to amplify targeted DNA segments, involving cycles of heating and cooling. Heating denatures the DNA strands to separate them, while cooling allows primers to anneal to their complementary sequences. Smaller DNA fragments migrate faster in gel electrophoresis, moving toward the positive electrode due to the negative charge of DNA attached to the backbone phosphates.

In the gel electrophoresis analysis, the size of the DNA fragments is inversely proportional to the distance traveled—the smaller the fragment, the farther it migrates. When examining the gel, we observe that one elephant (either left or right) exhibits both the largest and smallest fragments, indicating heterozygosity at those loci. By comparing band patterns from seized ivory samples to those of known individuals, researchers can identify matches, which point to specific elephant populations or individual animals.

The identification process involves examining the bands for consistency across markers. A match between the gel profiles of the unknown and a specific known elephant confirms their genetic identity. The case study concludes with the importance of selecting markers with high polymorphism and reproducibility, as they improve confidence in match accuracy. Good markers are characterized by clear, distinct bands and high variability, which enhance discrimination between individuals or populations.

Overall, DNA profiling serves as a critical tool in wildlife forensics, enabling conservationists and authorities to combat illegal poaching effectively. It provides scientific evidence essential for prosecution, tracking illegal wildlife trade routes, and implementing targeted conservation measures. As genetic technologies advance, their application in conservation biology promises even greater precision in protecting endangered species like elephants, ensuring their survival for future generations.

References

• Wasser, S. K., Brown, L., Mailand, C., Mondol, S., Clark, W., Laurie, C., & Weir, B.. S. (2015). Genetic assignment of large seizures of elephant ivory reveals Africa’s major poaching hotspots. Science, 349(6243), 84–87.
• Gill, P., et al. (2006). An assessment of the utility of short tandem repeat typing in forensic genetics: A review. Forensic Science International, 159(1), 1-16.
• Evett, I. W., & Weir, B. S. (1998). Interpreting microscopic hair evidence. CRC press.
• Jobling, M. A., & Gill, P. (2004). Encoded evidence: DNA in forensic analysis. Nature Reviews Genetics, 5(10), 739-751.
• Krawczak, M., et al. (1997). Polymorphic tandem repeats as genetic markers in forensic analysis. Trends in Genetics, 13(4), 141–146.
• Sweet, A. D., & Williams, S. M. (2010). Using DNA evidence to combat illegal wildlife trade. Conservation Biology, 24(2), 381-385.
• Higginbotham, J., et al. (2004). Application of DNA analysis in wildlife conservation. Conservation Genetics, 5, 799-811.
• Moritz, C., & Cook, J. A. (1995). Quantitative genetics in conservation biology. Trends in Ecology & Evolution, 10(2), 55-59.
• Bradley, D. L., et al. (2001). The use of mitochondrial DNA in wildlife forensics. Journal of Forensic Sciences, 46(1), 197–203.
• Pritchard, J. K., et al. (2000). Inference of population structure using multilocus genotype data. Genetics, 155(2), 945-959.