{"id":16031,"date":"2025-04-30T14:57:05","date_gmt":"2025-04-30T17:57:05","guid":{"rendered":"https:\/\/www.ufrgs.br\/ppgbm\/?p=16031"},"modified":"2025-04-30T14:57:05","modified_gmt":"2025-04-30T17:57:05","slug":"05-05-2025-seminario-de-qualificacao-doutorado-gustavo-medina-tavares","status":"publish","type":"post","link":"https:\/\/www.ufrgs.br\/ppgbm\/05-05-2025-seminario-de-qualificacao-doutorado-gustavo-medina-tavares\/","title":{"rendered":"05\/05\/2025 – SEMIN\u00c1RIO DE QUALIFICA\u00c7\u00c3O (Doutorado) – GUSTAVO MEDINA TAVARES"},"content":{"rendered":"

\u00a0<\/strong><\/p>\n

SEMIN\u00c1RIO DE QUALIFICA\u00c7\u00c3O (Doutorado)<\/strong><\/p>\n

 <\/p>\n

GUSTAVO MEDINA TAVARES<\/strong><\/p>\n

Diversity, demography, evolution, and health of Native Americans in South America: a mitogenomic perspective<\/strong><\/p>\n

Orientadora: Dra. Maria C\u00e1tira Bortolini<\/p>\n

Coorientadora: Dra. T\u00e1bita H\u00fcnemeier<\/p>\n

Banca examinadora: Dra. Lavinia\u00a0Schuler Faccini\u00a0 (PPGBM\/UFRGS) e Dra. Marcia Holsbach Beltrame (PPGBM\/UFRGS)<\/p>\n

05 de maio de 2025 (segunda-feira)<\/p>\n

10h30min<\/strong><\/p>\n

Presencial:\u00a0<\/strong>Anfiteatro do\u00a0Departamento\u00a0de\u00a0Gen\u00e9tica da UFRGS (Campus do Vale, pr\u00e9dio 43312)<\/p>\n

 <\/p>\n

Abstract<\/strong><\/p>\n

Brazil, home to more than 1.6 million Indigenous individuals across multiple ethnic groups, holds a wealth of genetic and cultural diversity that has been profoundly shaped by colonization and remains underrepresented in genomic research. By analyzing complete mitochondrial genomes (mtDNA) from both Indigenous and admixed individuals, this thesis aims to investigate mitochondrial genetic diversity and continuity, trace demographic patterns, assess admixture, and explore associations with health outcomes. The primary dataset comprises 3,813 mitogenomes obtained from whole-genome sequencing conducted as part of the DNA do Brasil project. Of these, 1,032 sequences are from Indigenous individuals belonging to seven different ethnic groups, and 2,781 are from admixed individuals from various regions. Analyses include assessments of haplogroup composition, haplotype diversity, demographic statistics (e.g., Bayesian Skyline Plots), and population structure (FST). In a subset of 467 COVID-19 patients, statistical (Chi-square and multivariate logistic regression) and machine learning approaches were applied to evaluate associations between mtDNA ancestry, specific variants, and disease outcomes. Our findings indicate that Native American haplogroup A2 (OR = 3.45, CI = 1.53\u20137.75, p = 0.0027) and nine specific variants\u2014particularly 8027A (MT-CO2 gene; OR = 3.27, CI = 1.64\u20136.52, p = 7.42 \u00d7 10\u207b\u2074; SHAP value = 0.013)\u2014are significantly associated with increased mortality risk in COVID-19 patients, even after adjustment for age, sex, six comorbidities, and FDR correction. These variants affect genes involved in oxidative phosphorylation and mitochondrial translation, and some (e.g., 8027A, PolyPhen-2 = 1.0) are predicted to have functional impact. Advanced age and male sex were also strongly associated, in accordance with current literature. On the diversity axis, patterns of mtDNA admixture\u2014especially in the Tupiniquim group\u2014highlight historical population dynamics marked by strong introgression of African lineages, while other Indigenous groups remain largely unadmixed. This thesis also includes a section related to education. A longitudinal study of over 150 million responses to Brazil\u2019s National High School Exam (ENEM) revealed persistent challenges in evolutionary biology comprehension (only 27.9% correct answers), with school type and scientific literacy as key explanatory variables, and religiosity to a lesser extent. Future analyses will expand demographic inferences and include additional ancient and modern published datasets. Altogether, the project aims to contribute to a more inclusive and precise understanding of Native American genetic history and health in South America, as well as to the broader discussion on evolutionary biology education.<\/p>\n","protected":false},"excerpt":{"rendered":"

\u00a0 SEMIN\u00c1RIO DE QUALIFICA\u00c7\u00c3O (Doutorado)   GUSTAVO MEDINA TAVARES Diversity, demography, evolution, and health of Native Americans in South America: a mitogenomic perspective Orientadora: Dra. Maria C\u00e1tira Bortolini Coorientadora: Dra. […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[108],"tags":[],"class_list":["post-16031","post","type-post","status-publish","format-standard","hentry","category-seminarios-e-defesas"],"_links":{"self":[{"href":"https:\/\/www.ufrgs.br\/ppgbm\/wp-json\/wp\/v2\/posts\/16031","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ufrgs.br\/ppgbm\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ufrgs.br\/ppgbm\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ufrgs.br\/ppgbm\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ufrgs.br\/ppgbm\/wp-json\/wp\/v2\/comments?post=16031"}],"version-history":[{"count":1,"href":"https:\/\/www.ufrgs.br\/ppgbm\/wp-json\/wp\/v2\/posts\/16031\/revisions"}],"predecessor-version":[{"id":16032,"href":"https:\/\/www.ufrgs.br\/ppgbm\/wp-json\/wp\/v2\/posts\/16031\/revisions\/16032"}],"wp:attachment":[{"href":"https:\/\/www.ufrgs.br\/ppgbm\/wp-json\/wp\/v2\/media?parent=16031"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ufrgs.br\/ppgbm\/wp-json\/wp\/v2\/categories?post=16031"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ufrgs.br\/ppgbm\/wp-json\/wp\/v2\/tags?post=16031"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}