December 6 2018

5:00 pm 1100 TLSB

EcoEvoPub Series

Graduate Student Presentations


Department of Ecology and Evolutionary Biology, UCLA

Human Reproductive Ecology: Insights from Evolutionary Medicine

Natural selection seeks to improve reproductive success, but its efforts can be exaggerated, often at the expense of our health. With the advent of food production 10,000 years ago and more recently, industrialization, culture and technology have outstripped our biological evolution creating anatomical and physiological mismatches to our environment. In our reproductive biology, these mismatches have manifested in ailments such as infertility, spontaneous abortion, pre-eclampsia, and polycystic ovaries. Through the lens of evolutionary medicine we can look at both the proximate and ultimate explanations as to why we are vulnerable to these diseases. This in turn has the potential to inform clinical medicine which is notorious for solely proximate reasoning. Additionally, anthropological studies show that ecological imprints can lead to a dramatic difference in reproductive physiology across populations. This shows that deviation in features such as age of menarche, menopause and hormone levels which may be classified as abnormal are just adaptations to either our contemporary or ancestral local environments. Clinical medicine will need to take this context dependency into consideration when designing drugs or therapies to prevent leaving underrepresented populations at greater health risk.

Department of Ecology and Evolutionary Biology, UCLA

When Form does not Predict Function: Empirical Evidence Violates Functional Form Hypotheses for Macroalgae.

Functional form groupings are widely utilized to reduce complexity and generalize across communities in many ecosystems. These models assume species within functional groups are similar in morphology and function, and thus predict they will respond similarly to key ecological drivers. We tested predictions of the Functional Group Model (FGM), a grouping for marine macroalgae widely used in both tropical and temperate systems to validate its underlying assumptions. The FGM predicts as morphological complexity increases, so will resistance to disturbance and herbivory due to greater thallus toughness. The FGM also predicts a tradeoff between morphological complexity and growth. To test predictions, we measured:

1) Thallus toughness (force to penetrate)
2) Tensile strength (force to break)
3) Relative growth for both tropical and temperate macroalgae from different functional groups.

Penetration strength followed model predictions at the functional group level, though there was significant variability among species. The model did not predict tensile strength at any level for either tropical or temperate macroalgae. Further, relative growth did not follow predictions\; rather it was highly variable species and functional groups. Thus, the underlying assumption that species within functional groups are more similar than between groups was violated, providing strong evidence that individual species need to be considered when predicting community responses to ecological drivers and challenging the usefulness of functional form groupings for marine macroalgae.




































































































































































































































































































































































































































































































































































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