Banca de DEFESA: EVELYN NATHÁLIA DA SILVA CRUZ

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : EVELYN NATHÁLIA DA SILVA CRUZ
DATA : 11/08/2021
HORA: 14:00
LOCAL: por participação remota
TÍTULO:

Were recent Pleistocene climate changes responsible for the extinction of gomphotherids in South America?

PÁGINAS: 43
GRANDE ÁREA: Ciências Biológicas
ÁREA: Zoologia
SUBÁREA: Paleozoologia
RESUMO:

The emergence of the Isthmus of Panama allowed for biota dispersions between North and South America, including two species of proboscids. Those species dispersed from North America and expanded their geographic distributions across the South American continent during the Pleistocene, between 2.6 million years and 11.7 thousand years before the present. Cuvieronius hyodon must have used the Andean region as a dispersal route, while Notiomastodon platensis probably expanded into the Amazon Crato. Both species became extinct about 9,000 years ago, and two hypotheses are proposed to explain such extinctions: hunting by the first human populations in South America, and the climatic variation of the last thousands of years. We tested the hypothesis of climate change over the last 120,000 years as the most important factor related to the extinction of gomphoterids in South America. We also explored possible dispersal routes of those species in South America. Our inferences were based on paleoclimatic models of the Last Interglacial (120,000 years before the present - AAP), the Last Glacial Maximum (21,000 AAP) and the Middle Holocene (8,000 AAP). We mapped the geographic distribution records available in scientific literature and open databases. We then identified climatically suitable areas for both species in South America through consensus projections of geographic distribution models, in the three periods of paleoclimatic models. Four bioclimatic variables related to the geographic distributions of living elephant species were used as predictors in species distribution models: Bio2 - Average monthly temperature range; Bio 6 - Minimum temperature of the coldest month; Bio7 - Annual temperature range; and Bio19 - Precipitation of the coldest quarter. Although both species were likely extinct before the middle Holocene, extensive areas of potential geographic distribution were identified as suitable by the models. We then reject the hypothesis that recent climate change of the Pleistocene would be one of the main factors responsible for the extinction of the two species of gomphoterids in South America.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1804548 - RICARDO JANNINI SAWAYA
Membro Titular - Examinador(a) Interno ao Programa - 1908726 - CIBELE BIONDO
Membro Titular - Examinador(a) Externo à Instituição - MÁRIO DANTAS - UFBA
Membro Suplente - Examinador(a) Interno ao Programa - 1154247 - FABIANA RODRIGUES COSTA NUNES
Membro Suplente - Examinador(a) Externo ao Programa - 2338944 - LEANDRO REVERBERI TAMBOSI