Ecology Quiz 2 Flashcards
Biologist who came up with idea of evolution separately from Darwin?
Alfred Russel Wallace
What are the tenets of Darwin’s theory of evolution?
- Organisms give rise to like organisms
- Variation between individuals
- Some traits heritable
- More offspring produced each generation than can survive
- Some individuals because of physical behavioral traits, have higher chance of surviving that others in population
Natural selection acts on___
individuals
Traits which give a fitness advantage in a given environment are called __
adaptations
Natural selection results in an __ in adaptive traits and ___ in maladaptive traits
Increase, decrease
Who came up with the ‘idea’ of particles of inheritance?
Gregor Mendel
Phenotypic variation among individuals in a population is a result of the combined effects of ___
genes and environment
What is a “common garden” experiment?
Bring plants from different places together to grow them in the same environmental conditions
In the common garden experiment if there was no genetic differences among the populations we would expect_
All plants to grow equally well in all gardens
What does Hardy-Weinberg Equilibrium state?
In a population, mating at random and absence of other evolutionary forces will cause allele frequencies to remain constant from generation to generation
What are 4 outcomes of inbreeding?
- Reduced fecundity
- depressed juvenile survival
- shortened life-span
- small body size
Te result of natural selection is__
predictable
Genetic drift results in _____changes
unpredictable
What are all 5 conditions necessary for Hardy-Weinberg Equilibrium?
- Random Mating
- No mutations
- Large population size
- no emigration/immigration
- equitable fitness between all genotypes
______impedes changes in a population, acts AGAINST extreme phenotype, favors average phenotype
Stabilizing selection
_______ leads to changes in phenotypes, favors EXTREME phenotype over other phenotypes in the population
Directional Selection
Under directional selection most phenotypes have___________ compared to exceptional phenotypes
Lower reproduction and survival
_______creates bimodial distributions, favors two (or more) extreme phenotypes, disfavors average
Disruptive selection
Natural selection -> changes in _____in a population can result in adaptation to the environment
genotypic and phenotypic frequencies
____can randomly change gene frequencies, especially in small populations
Genetic drift
There is a ____ between population size and genetic diversity
Positive correlation
Describe Island populations genetic variation
Genetic variation usually low and leads to less variation for natural selection to act on. BUT any new mutation is in relative high frequency in population and has greater likelihood of being maintained if beneficial or not.
Inbreeding leads to____in small populations
Higher extinction rates
Large scale weather variation
Macroclimate
Small scale weather variation (often measured over shorter period of time)
- elevation
- aspect
- vegetation
Microclimate
Describe specific heat capacity of water
- absorbs heat without changing temperature
- 1 calorie of energy to heat 1 cm3 of water 1 C
Describe latent heat of evaporation
1 calorie can cool 580 grams of water (580 mL)
Describe latent heat of fusion
1 gram of water gives off 80 calories as it freezes
Aquatic environments generally show ____ than do terrestrial environments
less temperature variation
____ is physiological changes in response to temperature (non-evolutionary , as it is over an organisms life span)
Acclimation
___ are extreme cold loving marine bacteria especially around Antarctica
Psychrophilic
Term for individual becoming more tolerant of its environment over lifetime
Acclimation
Vibrio bacteria are an example of ____
psychrophilic bacteria
Microbes loving extreme hot temperature are _
thermophilic
What is an example of thermophilic bacteria
Thermus aquaticus
What biome would you find thermophiles in ?
Desert
Organisms whose body temperature varies directly with environment?
Poikilotherms
Organisms whose body temperature is constant, regardless of environmental temperature?
Homeotherms
Organisms that rely on external energy sources for heat
Ectotherms
Organisms who rely on metabolic energy for heat
Endotherms
How do desert plants regulate their temperature?
- decrease heating via conduction (Hcd)
- Increase convection cooling (Hcv)
- Reduce radiative heating (Hr)
How do desert plant leaves help in maintaining temperature?
Desert plants reduce radiative heating (Hr) by orienting their leaves parallel to sunlight
How do arctic and alpine plants regulate temperature?
To stay warm they:
- Increase radiative heating (Hr)
- Decrease convective cooling
How do Rosette plants maintain temperature?
-retain dead leaves for insulation and protection from freezing temperatures. Thick pubescence increases leaves temperature
How do some grasshoppers regulate temperature as ectothermic animals?
Adjust temperature by varying intensity of pigmentation during development
___ is the range of environmental temperatures over which metabolic rate of homeothermic animal does not change
Thermal neutral zone
In what region of the world would you expect animals to have BROAD tolerances ?
Taiga
In which region of the world would you expect the most NARROW tolerances?
Tropical forests
Explain how sharks and other fish use swimming muscles to maintain temperature?
-lateral swimming muscles well supplied with blood vessels, they use counter current heat exchange. As warm arterial blood is pumped away from heart, heat is transferred to venous blood and warmed as it returns to heart
How do sphinx moths maintain temperature ?
They increase thoracic temperature through flight, thermoregulative transferring of heat from thoracic to abdomen
Almost all plants are considered____
poikilothermic ectotherms
How does skunk cabbage regulate its temperature?
-Stores starch in roots -> translocates it to inflorescence-> metabolizes it-> generates heat
What are two ways to survive extreme temperatures?
- Inactivity (STAY INSIDE)
- Reduce metabolic rate (hibernation, estivation)
How do hummingbirds reduce metabolic rate when food is scarce or night temps are extreme?
They enter state of torpor when food is scarce or night temperatures are extreme
- hibernation during the winter (cold)
- estivation during the summer (dry)
