Banca de DEFESA: JULIMAR FREIRE DE FREITAS NETO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : JULIMAR FREIRE DE FREITAS NETO
DATE: 02/03/2026
TIME: 14:00
LOCAL: https://meet.google.com/jkv-nivi-pip
TITLE:

Contributions to the Family Geastraceae Corda (Geastrales, Basidiomycota): Divergence Times, Historical Biogeography, Niche Modeling, and Taxonomy

KEY WORDS:

Ancestral reconstruction; Climatic suitability; Divergence times; Earthstar; Gasteroid fungi; Integrative taxonomy.

PAGES: 124
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

The family Geastraceae (Geastrales, Basidiomycota) comprises widely distributed gasteroid fungi, notably the genera Geastrum and Myriostoma, which are recognized for their morphological diversity and ecological relevance as decomposers of organic matter. Despite their taxonomic and biogeographic importance, these groups remain insufficiently explored under integrative frameworks combining phylogeny, historical biogeography, and ecology. This study integrated Bayesian phylogenetic analyses calibrated with fossil and secondary age constraints to estimate divergence times, along with ancestral biogeographic reconstructions to infer areas of origin and dispersal routes. Ecological niche modeling of Myriostoma calongei and M. coliforme was conducted using MaxEnt and Random Forest algorithms combined in ensemble models, based on climatic and topographic predictors selected after multicollinearity tests. Occurrence records from herbaria, literature, and curated databases were spatially filtered to reduce sampling bias. Divergence time estimates and ancestral area reconstructions indicate an Eocene origin (~40 Myr) of Myriostoma in the Northern Hemisphere, followed by dispersal and diversification associated with paleoclimatic events. Niche models revealed ecological differentiation between the species, with distinct associations to thermal and precipitation regimes and potential conservation implications under climate change. Revision of scientific collections significantly expanded the known distribution of M. calongei in the Neotropics, including its first record for Uruguay and new occurrences across Brazilian biomes. Additionally, a new Neotropical species of Geastrum was described based on an integrative approach combining morphological and molecular data. These findings highlight the importance of integrating taxonomy, phylogeny, biogeography, and environmental modeling to understand the diversity and evolutionary history of Geastraceae.

COMMITTEE MEMBERS:
Interno - 1545394 - FULVIO AURELIO DE MORAIS FREIRE
Externa à Instituição - GISLAINE CRISTINA DE SOUZA MELANDA - NÃO INFORMADO
Presidente - 1452763 - IURI GOULART BASEIA
Externa à Instituição - NATHALIA MENDONÇA DE ASSIS
Externo à Instituição - RENATO JUCIANO FERREIRA - URCA