BIOL251 Exam Flashcards
Example exam Q:
Draw a conceptual diagram to illustrate how a temporal
correlation between increased abundance of deer and
decreased abundance of caribou may be mediated by
several different types of ecological interactions.
TBC
Exam Q:
Describe the flow of nutrients through an ecosystem,
indicating where there might be limitations and what
factor(s) are involved in these limitations
TBC
What are the four biological disciplines?
- evolution - natural selection
- physiology - environmental tolerance & metabolism
- behavioural - dispersal & territoriality
- Genetics - adaptations
Describe an experiment analysing the complex patterns and processes (interactions) of ecology.
Frog deformities case study:
Testing if pesticides or parasites caused deformities in frogs.
6 ponds with deformed frogs:
- tadpoles placed in mesh cages, some ponds has pesticide absent and some present.
- split in 2, large mesh allowed parasite to pass through
- small mesh prevented parasite
Results: Small mesh with presence and absence of pesticide posed same results: no deformities
Large mesh with both presence and absence of pesticides had deformities, but highest deformity % was with pesticides.
Variables to consider:
1. Nitrogen from fertilisers provides algae blooms and more nutrients for snails (parasite host)
2. pesticides weakens frogs resistance to parasite
3. Climate change and increased UV makes them less resistant
4. When infected as a tadpole, they die before metamorphosis
5. deformities in frogs makes them more susceptible to predators
What is evolution?
Change over generations within a population
Properties of a population is not from anticipation of the future, instead the result of past evolutionary change,.
What are some requirements for natural selection?
- Inheritence
- Variation
- Relative fitness (offspring)
- Reproduction (intra and intersexual selection)
- Fitness
What are some evolutionary Constraints?
temperature
natural disasters
extinction
What are some modes of evolution that are non-adaptive?
- Genetic Drift
–> gene freq. in a small population can change dramatically via
a) Bottlenecking (natural disaster)
b) founder (isolation - darwins finches)
c) Fragmented habitat ( geographic barriers) - mutations
- how variations arise - Geneflow
- counteract effects of natural selection
- transfer of genes from one population to another - non-random mating
- sexual selection
Distribution and Abundance:
Describe Rapoport’s rule and and suggested hypotheses.
Definition:
describes why geographic distribution differs between high and low altitude for mammal species. This hypothesis considers how environmental variability (climate, glaciation and lack of competition) can impact species richness across latitudes.
Polar species have larger geographic ranges than tropical species.
Environmental variability rises with increasing latitude as it provides more ecological opportunities and broader variations in habitat for species.
→high seasonal variation
→decreased competition
→various adaptations leads to higher rates of speciation
Low latitudes: species experience more stable environmental conditions, resulting in smaller ecological niches and geographic range.
→less seasonal variation
→increased competition
→species become more specialised
Hypothesis: Climate variability, glaciation, lack of competition.
Species thermal tolerance
Mammals generally only found in poles.
Define, and in examples (real and hypothetical), distinguish between the fundamental niche and the
realised niche
Fundamental Niche: ideal, Ecological space occupied by a species in absence of competition and other interactions with species.
Hypothetical Fundamental
Bird species can tolerate range of temperatures, eat range of foods, and nest anywhere
Hypothetical
Coyote species can survive in forests to deserts.
Realised Niche: Realistic environment, a species can only use limited resources of an area because of interactions with other species
Real Bird:
Can only nest in one species of tree due to competition
Real Coyote
Competition with other carnivores and humans, results in a much narrower habitat range
Describe Hanski’s Rule (1982) and reasoning of Distribution and Abundance:
Describes the positive correlation between distribution and species abundance
Species with wider distributions are more abundant.
Reasoning:
Sampling issues - over a wide scale its hard to not recount individuals
Generalist species: eats anything tends to be more distributed than species who are ‘picky’ with their resources - narrow range
what are the main drivers of distribution?
Abiotic: Light, temp, oxygen
Biotic: Compeition, predation, disease
Behaviour: habitat selection and dispersal
Disturbance: Natural or human cased
What are the limitations of rapoports rule?
Does not consider all species (only mammals)
Does not consider elevations
Explain Acclimatisation versus Acclimation versus adaptation
Acclimation:
reversible physiological or behavioral response of an individual organism to short temporal
changes in its environment
ie: temperature alone
Acclimatisation
similar, but old and new environment differ in many ways
(Winter and Summer)
**Both are a form of phenotypic plasticity
Adaptation: changes in a population over time in response to environmental pressures.
Both Adaptation and Acclimation are essential for organisms to respond and persist in their environments,
How would you test acclimation?
Lab experiment: over short period
- individuals breed in different conditions
- Transgenerational acclimation: how parental tolerance affects offspring.
- measure thermal tolerances: raising them in similar conditions
- if temperature curves are maintained, it is a fixed trait
Provide an example of acclimation (temperature):
Black rock cod:
Enzymes denature >5 degrees
Developed lack of RBCs since metabolism is so slow, their bloodstream can carry oxygen on its own since oxygen concentrations in cold water are so high
What are some moisture adaptations?
Waxy cuticles - plants
Frogs can apply muscous layer in a burrow to avoid dessication when ponds dry up (mains frog)
- mass breeding events
Lizards developed rough skin and scales
Get water from mist and water droplets on skin and consuming insects.
Describe an interaction of abiotic factors (light, temp and moisture on a species)
Western Hemlock (tree)
Very water hungry - short roots, loose water rapidly
Needs to be in high humidity environments
Describe adaptations to changes in light, moisture, and temp
Photosynthetic pathways (C3, C4, CAM)
CAM plants open stoma at night to avoid dessication
- adapted to live in arid/semi arid locations
Can photosynthesis without opening stoma during the day as they store CO2 at night.
What are some examples of physical and chemical interactions?
- soil resources and texture
- salinity, acidity, oxygen
Mudskippers:
Semi-Terrestrial
Air pockets functioning like lungs.