Abstract Detail

Biogeography

Bitencourt, Cássia [1], Rocha, Lamarck [2], Andrade, Maria José Gomes de [3], Trovó, Marcelo [4], Watanabe, Maurício [5], Echternarcht, Lívia [6], Giulietti - Harley, Ana Maria [7], Ribeiro, Patrícia Luz [8].

Divergence Time, Biogeography and Diversification of Eriocaulaceae (Poales).

Eriocaulaceae is a pantropical family consisting of approximately 1,400 species which diversified mostly in the old highlands of New Word. It has a diverse morphology, easily distinguished from other monocots by a set of traits like a scape topped by capitulum with small unisexual flowers and spiraperturate pollen grains. Despite continuous effort on the systematics of the genera, no detailed analysis has been developed to estimate the origin and diversification of this family in space and time. A time-calibrated phylogeny of the Eriocaulaceae can assist the understanding of its spacial, morphological, ecological and temporal evolution, hence, the evolutionary history of the biomes in which they occur. Here, we build the most robustly sampled, time-calibrated phylogeny of Eriocaulaceae, including approximately 15% of its species, and use it to investigate its biogeographical history and also the diversification dynamics through time, defining main shifts on rates. Our reconstructions indicate the origin of Eriocaulaceae in middle-Cretaceous. The initial divergence of the family gave rise two groups, which correspond to the subfamilies Eriocauloideae and Paepalanthoideae. We showed that Eriocauloideae diversified in the late Cretaceous before Paepalanthoideae which diversified between Paleocene and early Eocene. In Eriocauloideae, Eriocaulon diversified more recently but has the more widely distribution of the family, including temperate areas. The origin of Paepalanthoideae comprise the southern Espinhaço Range (Eastern Brazil) and the Guiana Highlands, and the split of the genus Paepalanthus and other genera was given by a vicariant event. The Paepalanthoideae has been isolated on Campo Rupestre of Espinhaço Range and the Tepuis of Guiana Highlands for a long time, showing high rates of in situ diversification to Paepalanthus and few exchanges to other areas. We found an increasing of rates of diversification from the late Oligocene to the present in the Paepalanthus related species while major other lineages diversified since Miocene. Instead, Leiothrix a typical genus of the Espinhaço Range, which diverged in early Miocene, has not showed a high increase on diversification rates. Our results suggest that spatial patterns in diversification of Eriocaulaceae are mainly associated with environmental drivers, that could lead to a key innovation which allowed their persistence on these landscapes for a long-time.

1 - Universidad Nacional Autonoma do México, 3493 Avenida Insurgentes Sur, Ciudad de México, Distrito Federal, 14250, México
2 - Universidade Federal do Rio Grande do Norte, Brazil
3 - Universidade do Estado da Bahia, Brazil
4 - Universidade Federal do Rio de Janeiro, Brazil
5 - Instituto Tecnológico Vale, Belém, Brazil
6 - Universidade Federal de Ouro Preto, Brazil
7 - Universidade Estadual de Feira de Santana, Brazil
8 - Universidade Federal do Recôncavo da Bahia

Keywords:
Eriocauloideae  
Paepalanthoideae
Campo Rupestre
Tepuis
Espinhaço Range
Guiana Shield
Neotropical Diversity
continental disjunction.

Presentation Type: Oral Paper
Session: BIOGII, BIOGEOGRAPHY II
Location: Virtual/Virtual
Date: Tuesday, July 20th, 2021
Time: 11:00 AM(EDT)
Number: BIOGII005
Abstract ID:782
Candidate for Awards:None