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Full-Text Articles in Life Sciences

Exploring Zosterophyll Relationships Within A More Broadly Sampled Character Space: A Focus On Anatomy, Megan Nibbelink Jan 2021

Exploring Zosterophyll Relationships Within A More Broadly Sampled Character Space: A Focus On Anatomy, Megan Nibbelink

Cal Poly Humboldt theses and projects

Important constituents of Siluro-Devonian floras, zosterophylls gave rise to the lycophytes. I explore the relationships of 18 zosterophyll species from 16 genera, maximizing sampling of anatomy. Using phylogenetic and phenetic methods, I (1) assess the influence of tree rooting, taxon sampling, and morphological vs anatomical characters on the stability of relationships; and (2) compare phylogenetic and phenetic methods in terms of relationships recovered. Phenetic analyses show sensitivity to taxon sampling and support placement of Renalia among zosterophylls, but do not provide results that are strongly congruent with those of phylogenetic analyses. Phylogenetic analyses demonstrate that taxon and character sampling significantly …


Analysis Of The Variables Affecting Plant Species Richness In Deserts, Eli R. Kallison, Ellen Thompson, Maddison Keen, Rusty Newman Oct 2020

Analysis Of The Variables Affecting Plant Species Richness In Deserts, Eli R. Kallison, Ellen Thompson, Maddison Keen, Rusty Newman

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

There are many hypotheses that attempt to explain patterns of species diversity in different environments. Deserts are a great place to study changes in species richness because they are relatively nutrient bare and exhibit low precipitation. This barebones environment means that slight shifts in climate and geography may lead to clear changes in species richness. We investigate how temperature, precipitation, water and light availability, latitude, elevation and other variables affect plant species richness in 20 deserts.