On the importance of functional traits and of phylogenetic relationships in marine nematodes: eco-evolutionary perspectives
Data
2022-09-23
Autores
Johnson da Silva, William 
Orientadores
Fonseca, Gustavo
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
As espécie possuem diversas características que as permitem explorar determinados nichos, exercendo e sofrendo influência nas inúmeras relações e processos ecológicos que ocorrem nos ecossistemas. Essas características podem ser, por exemplo, de natureza funcional, filogenética ou comportamental, e ao longo do tempo evolutivo estruturam a forma como as comunidades são hoje. Embora estudos ecológicos utilizando atributos funcionais e a posição filogenética das espécies de Nematoda marinhos sejam comuns, algumas estruturas morfológicas dos Nematoda recebem termos ambíguos. Além disso, a integração dos atributos funcionais e filogenéticos a medidas como amplitude (NB) e posição dos nichos (NP) das espécies ainda é incipiente, e entender este panorama é crucial para a compreensão da história evolutiva e da dinâmica das comunidades. Esse entendimento é ainda mais relevante em ambientes com alta diversidade como o mar profundo. Desta forma, este trabalho teve como objetivo entender se atributos funcionais e filogenéticos podem predizer a amplitude e posição dos nichos das espécies de Nematoda. Para isto, investigamos organismos coletados na Bacia de Santos, SP - Brasil e separamos os termos traços funcionais (aqueles com relação ao funcionamento do ecossistema) de morfologia funcional (aqueles com influência na performance individual do organismo. Comprimento/largura (L/W), forma do corpo, estratégia trófica, tipo de cauda e estratégia de vida são compreendidos como traços funcionais. Ao passo que anfídeo, cutícula e setas somáticas podem ser consideradas morfologias funcionais. Os caracteres funcionais, juntamente com a posição filogenética, e o ambiente de ocorrência (plataforma continental ou mar profundo) foram utilizados para prever os nichos da espécie a partir do método de Random Forest. Agrupamos as 50 espécies de Nematoda em 4 grupos de acordo com as similiaridades da amplitude (NB) e posição de nicho (NP). O modelo demonstrou que a taxa de acurácia para os grupos e para cada espécie depende do ambiente. As espécies de mar profundo são mais previsíveis do que as da plataforma continental. Os atributos funcionais mais importantes revelados pelo modelo foram o tipo de cauda móvel e hemi-sésseis, e as formas de corpo escavadoras e intermediárias. Estes traços ocorreram em espécies muitas vezes distantes filogeneticamente, mas que têm características que convergem para determinadas funções, evidenciando um processo de convergência evolutiva, sobretudo em regiões profundas. Nas regiões rasas, por outro lado, os traços funcionais não foram suficientes para predizer os o grupo das espécies, e muitas vezes nem em combinação com os filogenéticos. Dessa forma, nossos resultados mostram que distintos processos evolutivos ocorrem entre a plataforma e o mar profundo, e que a heterogeneidade do habitat atrelada às variações dos traços entre as espécies pode ser responsável por esta distinção entre os processos.
Species have several characteristics that allow them to explore certain niches, exerting and being influenced by the countless relationships and ecological processes that occur in ecosystems. These features can be, for example, of a functional, phylogenetic or behavioral nature, and over evolutionary time structure the way communities are today. Although ecological studies using functional attributes and the phylogenetic position of marine Nematoda species are common, some Nematoda morphological structures receive ambiguous terms. In addition, the integration of functional and phylogenetic attributes to measures such as amplitude (NB) and position of niches (NP) of species is still incipient, and understanding this panorama is crucial for understanding the evolutionary history and dynamics of communities. This understanding is even more relevant in environments with high diversity such as the deep sea. Thus, this work aimed to understand whether functional and phylogenetic attributes can predict the amplitude and position of niches of Nematoda species. For this, we investigated organisms collected in the Santos Basin, SP - Brazil and separated the terms functional traits (those related to the functioning of the ecosystem) from functional morphology (those with influence on the individual performance of the organism. Length/width (L/W), body shape, trophic strategy, tail type and life strategy are understood as functional traits. Whereas amphid, cuticle and somatic setae can be considered functional morphologies. The functional characters, together with the phylogenetic position, and the environment of occurrence (continental shelf or deep sea) were used to predict the niches of the species using the Random Forest method. We grouped the 50 Nematoda species into 4 groups according to similarities in amplitude (NB) and niche position (NP). The model demonstrated that the accuracy rate for groups and for each species depends on the environment. Deep sea species are more predictable than continental shelf species. The most important functional attributes revealed by the model were the movable and hemi-sessile tail type, and the burrowing and intermediate body shapes. These traits occurred in species that are often phylogenetically distant, but which have characteristics that converge to certain functions, showing a process of evolutionary convergence, especially in deep regions. In the shallow regions, on the other hand, the functional traits were not enough to predict the group of species, and many times not even in combination with the phylogenetic ones. Thus, our results show that different evolutionary processes occur between the shelf and the deep-sea, and that habitat heterogeneity linked to variations in traits between species may be responsible for this distinction between processes.
Species have several characteristics that allow them to explore certain niches, exerting and being influenced by the countless relationships and ecological processes that occur in ecosystems. These features can be, for example, of a functional, phylogenetic or behavioral nature, and over evolutionary time structure the way communities are today. Although ecological studies using functional attributes and the phylogenetic position of marine Nematoda species are common, some Nematoda morphological structures receive ambiguous terms. In addition, the integration of functional and phylogenetic attributes to measures such as amplitude (NB) and position of niches (NP) of species is still incipient, and understanding this panorama is crucial for understanding the evolutionary history and dynamics of communities. This understanding is even more relevant in environments with high diversity such as the deep sea. Thus, this work aimed to understand whether functional and phylogenetic attributes can predict the amplitude and position of niches of Nematoda species. For this, we investigated organisms collected in the Santos Basin, SP - Brazil and separated the terms functional traits (those related to the functioning of the ecosystem) from functional morphology (those with influence on the individual performance of the organism. Length/width (L/W), body shape, trophic strategy, tail type and life strategy are understood as functional traits. Whereas amphid, cuticle and somatic setae can be considered functional morphologies. The functional characters, together with the phylogenetic position, and the environment of occurrence (continental shelf or deep sea) were used to predict the niches of the species using the Random Forest method. We grouped the 50 Nematoda species into 4 groups according to similarities in amplitude (NB) and niche position (NP). The model demonstrated that the accuracy rate for groups and for each species depends on the environment. Deep sea species are more predictable than continental shelf species. The most important functional attributes revealed by the model were the movable and hemi-sessile tail type, and the burrowing and intermediate body shapes. These traits occurred in species that are often phylogenetically distant, but which have characteristics that converge to certain functions, showing a process of evolutionary convergence, especially in deep regions. In the shallow regions, on the other hand, the functional traits were not enough to predict the group of species, and many times not even in combination with the phylogenetic ones. Thus, our results show that different evolutionary processes occur between the shelf and the deep-sea, and that habitat heterogeneity linked to variations in traits between species may be responsible for this distinction between processes.
Descrição
Citação
JOHNSON-SILVA, William. On the importance of functional traits and of phylogenetic relationships in marine nematodes: eco-evolutionary perspectives. 2022. 64 f. Dissertação (Mestrado em Biodiversidade Marinha e Costeira) - Instituto do Mar, Universidade Federal de São Paulo, Santos, 2022.