SUSTENTACIÓN DE TESIS - MARÍA ALEJANDRA CORONEL GUZMÁN

Value of the Information & Strength of the Argument

The value of the information lies in the presentation of original genetic data from ancient populations in a region that has been understudied genetically. The argumentation is solid, as the student systematically describes the methodology, results, and their interpretation, comparing with published data. The use of multiple analytical methods (Fst, PCA, networks, phylogenetic trees) strengthens the conclusions. However, the small sample size and the preliminary nature of the results limit the generalizability. The student also acknowledges the challenges of ancient DNA work, which adds credibility.

Scientific Rigor, Source Quality, Title Accuracy

The scientific rigor is evident in the careful laboratory protocols to avoid contamination, the use of appropriate software, and the comparison with published datasets. The sources cited include the Cambridge Reference Sequence, PhyloTree, and various studies (e.g., by Llamas, Perego, and others) for haplogroup assignments and coalescence times. The title accurately reflects the content, and the presentation is well-structured. The defense includes a question period where the student answers queries, demonstrating her understanding. The video is a formal academic presentation, and the quality of sources is appropriate for a thesis defense.

The title accurately reflects the content: a thesis defense on the phylogenetic characterization of mitochondrial DNA from pre-Columbian remains in the Lower Magdalena region.

7/10

The thesis defense presents original research with a clear methodology, but the video is a recording of a presentation, not a peer-reviewed publication. The results are preliminary and the sample size is small. The speaker is a master's student, and the work is supervised by experts. The presentation is coherent and follows scientific standards, but the lack of detailed data and the informal setting limit the score.

Markers derived by PSI from the transcript: the creator did not define chapters.

• 00:00Introduction and reading of the act of defense
• 02:00Introduction to the study: Magdalena River basin and migration routes
• 05:00Explanation of mitochondrial DNA as a genetic marker and its use in human evolution
• 10:00Objectives and sample collection: 42 dental samples from five archaeological sites
• 15:00Methodology: DNA extraction, PCR amplification, and sequencing
• 20:00Results: haplogroup assignment and genetic diversity indices
• 25:00Interpopulation analysis: Fst distances and PCA
• 30:00Phylogenetic networks for each haplogroup and comparison with other populations
• 35:00Discussion: implications for migration routes and genetic diversity
• 40:00Conclusions and future directions: complete mitogenome analysis

• PhyloTree — Used for haplogroup assignment
• Cambridge Reference Sequence — Reference for mtDNA comparison
• Study by Llamas et al. (2016) — Cited for coalescence times and haplogroup distributions
• Study by Perego et al. (2010) — Cited for haplogroup A2 and B2 distributions
• Thesis by Adriana Pérez — Provided comparative ancient DNA data from Colombia

• Llamas et al. (2016) — Their study on ancient mitochondrial DNA diversity in the Americas supports the high diversity and migration patterns observed.
• Perego et al. (2010) — Their work on haplogroup distributions in the Americas is consistent with the findings.

• Some studies on modern populations — The high diversity in ancient populations contrasts with lower diversity in some modern populations, but this is expected due to genetic drift and admixture.