系统发生学与进化生物学杂志

Ferns (Pteridophyta) are free-sporing vascular plants that have a unique life cycle with free-living gametophyte and sporophyte phases. The fern species has nearly 90% of the extant diversity, it was the first higher-level of pteridophyte classification in the world. This study aimed to assess and identify the different species composition and diversity variation of ferns found in the lower elevations at the primary forest in Barangay San Rafael, Prosperidad Agusan del Sur, Philippines. Moreover, the researchers were used the quadrat sampling method as one of the best and classic tools utilized in ecology especially determining the diversity of a specific sampling sites. Also, the study used Shannon’s diversity index method in determining the biological diversity of plant species particularly ferns (Pteridophyta). The total number of ferns that was primarily collected at Barangay San Rafael, Prosperidad, Agusan del Sur are nine (9) species from 5 families. The researchers linked the gathered data of ferns (Pteridophyta) by calculating its diversity index of 1.864, were showed medium diversity because most likely the pteridophyte communities were similar in all transects. Thus, the study area has medium species diversity results in a more complex, stable, and productive ecosystem as could be observed in San Rafael Forest. The results show that the growth and distribution of ferns was inhibited significantly by the environment properties.

Two main approaches, relying on only genetic drift and considering both genetic drift and mutations in equilibrium, are keys in revealing genetic distance and relevance among populations. Genetic relations and histories of communities can be unearthed by utilizing these methods accurately. For this reason, the equilibrium method should be definitely used to identify blood ties and migration waves. F_ST, therefore also phenotypes should be utilized in understanding habitats’ adaptational effects whereas F_ST and phenotypes are not sufficient to disclose blood ties. Thus bonds among migration, genotype, phenotype and origin will be resolved truly. Those are clear phenotypes extremely depend on habitats, especially climates as expected and genotypes hide collective origins over mutational roots. Then formation and evolution areas of populations can be detected via the equilibrium method and F_ST respectively. Even rates of genetic drifts can be calculated by measuring the alteration of phenotypes. Moreover some organisms’ genes could be regulated stably in the laboratory in part natural manner when habitats’ effects on genetic drifts were revealed.