Exam 1 Flashcards
What is Ecology?
The study of 1) an organism’s interactions with their physical and biological environments and 2) how those interactions shape their distribution + abundance.
Why study ecology?
1) concept of limitation: resources are not infinite, need to conserve and protect.
2) Concept of inter-relatedness: between organisms + environment.
5 threats to marine biology
- Fisheries, 2. global climate change, 3. dramatic change in/loss of/alteration of habitat, 4. invasive species, 5. chemical pollution and eutrophication
Reductionist Approach
A scientific approach of learning about something by breaking it into smaller parts and studying those parts.
Temporal Variation can be…
Predictable: seasonal or daily schedules.
Unpredictable: More extreme conditions are less frequent and predictable.
Spatial Variation
Can be on a small scale (forest sunflecks) or large scale (latitudinal variation in solar plexus). Scale of variation is important to the function of an organism.
Experimental Design
- Must be able to replicate.
- Must have random distribution of treat.
- Results found using statistical analysis.
Laboratory Experiments
Most exact regulation of abiotic and biotic factors, vary only factor of interest. Disadvantage in oversimplification of biotic community. Best use in physiological responses in individuals.
Field Experiments
Conducted outdoors, manipulation of abiotic or biotic factors. Disadvantage: methods of exclusion are unlikely to be generated in nature.
Natural Experiments
Uses natural perturbations (ex. tsunami) to disrupt biotic community. Used to follow the trajectory of the perturbation over time. Results can be extrapolated to other communities.
Experimental problems
Correlation does not = causation; sometimes scale is too large to perform (pattern of evolution or spatially), casual factors can’t be independently tested.
Microcosms
replicate essential features of the system in a field or laboratory setting.
4 Categories of Rapid Evolution
- Evolution of trophic links via specialization (ex. Darwin’s finches)
- Evolution of defense (moths)
- Rapid loss of traits in response to absence of interaction (defensive traits in guppies)
- Niche Theory: realized niche constrained by biological interactions among species)
Niche
An organism’s place in environment defined by physiological tolerances and resource requirements.
Force: No-slip condition
Fluid in contact with solid surface doesn’t slip; easily to be moved away from environment closer to the surface and easier to bear closer to the boundary layer.
Force: Drag + Drag resistance
All actions have an equal and opposite reaction. (if force exerts by one body, will also be received by the organism acting against it).
Minimizing strategies: flexibility (reduce area affected), collapsing (holly bush), drag resistance (wider base + buttresses in trees), evolve or develop streamlined bodies.
Force: Pressure
Bernoulli’s principle
Principle of continuity
Bernoulli’s principle: pressure is inversely proportional to velocity.
Force: Lift
Can either maximize (bird wings) or minimize (limpets sticking to rocks)
Flow affects…
- Shape + performance
- exchange processes
- fitness
- distribution of organisms
- transport processes
Scaling
relating body size to an entity or process
Size affects…
Gravity: circulation, movement + locomotion
Surface Area/Volume Ratio: respiration + digestion, water balance, thermoregulation
Allometry
The study of differential growth and biological scaling
Three types of allometric scaling
Isometric: b = 1
Negative: b < 1
Positive: b > 1
(True when measure like dimensions)
Geometric (Isometric) Scaling
Preserve basic shape as size changes
How can animals increase in size without being “all skeleton”?
Animals accept lower safety factor. Experience a decrease in locomotor functions, alter morphology to reduce skeleton stress, or alter chemical composition of skeleton.
Keiber’s Rule
Metabolic rate = M^0.75
Energetic Equivalence
total energy flux of a population invariant with respect to body size.
Global Size Density Relations
Data from literature, densities from any point on the globe.