Organismal Ecology

Question 1

1. A fundamental goal in physiological ecology has been to establish mechanistic connections between physiological traits and fitness. In your opinion, have we already learned what we need to know (more or less), or should that remain an important goal moving forward? Be specific with respect to areas of ecology and evolutionary biology for which that physiology and fitness connection is (or has been) most important.

Answer 1

• Define physiological ecology: an organism’s physiological response to its environment
• What are the mechanistic connections between physiological traits and fitness
• Choose opinion: we have or have not learned enough
• Defend the opinion, especially relative to ecology and evolution
• Fitness and physiology in a variable environment - Kimball et. al. 2012
• How physiological traits are heritable
• Mechanisms of gene expression leading to physiological traits
• Still so much to know regarding plasticity, epigenetics, and more
• Climate change
• Genotypes do not equate to one phenotype
• Cite Mike Logan if possible

Question 2

2. What are the fundamental physiological challenges associated with living in terrestrial versus aquatic environments? How have organisms overcome these challenges?

Answer 2

• water: terrestrial organisms struggle with water loss, aquatic need water barrier
• temperature: terrestrial organisms must be able to tolerate large temperature swings, aquatic environments are generally stable
• gas exchange: ?
• ultraviolet radiation: terrestrial organisms struggle, aquatic are mostly protected
• gravity and pressure: terrestrial organisms need to be more supported, aquatic organisms do not
• ocean acidification: aquatic organisms struggle, terrestrial organisms do not
• overcome with different physiological adaptations: homeostasis, skin barrier, colors, skeletons, etc.

Question 3

3. Life history strategies (patterns of growth and reproduction) are thought to evolve, at least in part, in response to environmental conditions. What are some of the classic ecological models that describe expected evolutionary responses in different environments? Describe some of the life history features of organisms at different ends of these spectra, as well as the assumptions implicit in these models. What evidence is there to support these ideas?

Answer 3

• Define life history strategies and traits: how organisms divide their resources into survival, growth, reproduction and parental care. “Optimization” theory and trade-offs.
• Examples of widely different organisms that are typically classified as r-strategists and K-strategists.
• Connect life history theory with selection, fitness and adaptation. Different strategies are evolutionary products of various selective pressures, evolutionary constraints…
• Describe experimental studies where life strategies have been shown to rapidly adapt across generations (Stearns’ fruit flies, Reznick’s Trinidad guppies etc).

Question 4

4. Many factors affect habitat or resource selection by animals. Describe how the different requirements of animals affect selection of resources, especially in the context of ecological tradeoffs between risks and benefits. Discuss how resource selection at the level of the population is affected by heterogeneity among individuals. How do anti-predator or ‘risky’ behaviors affect habitat selection?

Question 5

5. Explain Tinbergen’s four questions, and their utility for studying behavior. Should they always be addressed separately? If so, why? If not, why not?

Answer 5

1. How does behavior develop? - This refers to development or why a behavior would develop in an individual or species. Also refers to how a behavior developed in one organism during its lifetime.
2. What causes behavior? - This refers to causation or why a behavior would be adopted by an individual or species. What stimuli or what physiological methods cause this behavior?
3. Survival value of behavior - This refers to the adaptive advantage or function of a behavior or how a behavior helps an individual or species and how it improves animal survival.
4. Evolution of behavior - This refers to the evolutionary history (phylogeny) of a trait and why an individual or species may have evolved a specific trait and how this behavior evolved over time.

• These questions CAN be addressed separately to answer specific questions, but should be considered part of the larger picture

Question 6

6. The question of what keeps signals honest has been a subject of much historical and current debate in the field of animal behavior/communication. Explain “the problem of reliability”, and describe a few selected examples (both theoretical and empirical) that you would use in teaching a section of an undergraduate course on the evolution of reliable signaling.