Populations of the same species that occur in contrasting environments are subject to divergent natural selection pressures due to different environmental characteristics. This can cause a decrease in gene flow between them, which can lead to the development of reproductive barriers, in addition to an intraspecific variation in morphological attributes, between populations. This process is called ecological speciation, and proceeds initially through an ecotypic phase, and later, with the gradual evolution of the mechanisms of genetic isolation until the possible formation of a new species. This project seeks to analyze the reproductive compatibility and the morphological variation of flowers among four populations of Epidendrum fulgens (Orchidaceae), two of them located in a restinga area and two in a rocky outcrop area, which are geographically separated from the restinga populations. Since the populations of E. fulgens restinga and rocky outcrops occur in contrasting environments and present high genetic differences, representing two distinct ecotypes, we hope to detect among them greater floral morphological differentiation and evidence of reproductive isolation. To test our hypotheses, we will conduct experiments of manual crosses between individuals of E. fulgens from the four populations kept in cultivation, in order to detect evidence of reproductive isolation, in addition to analyzes of floral morphometry in individuals that will be collected in the field, in order to detect patterns of morphological differentiation. This project aims to help elucidate questions about the processes that operate during the initial stages of speciation.
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