Who came up with the idea of natural selection besides Darwin?
Alfred Russel Wallace
Phenotypic environment = ____ + _____
genes + environment
Natural selection acts on _______.
individuals
Traits which give fitness advantage in a given environment are called ________.
adaptations
Evolution is a ______ in the allele _______ in a population over _____.
change frequency time
Natural selection results in an increase in adaptive traits and decrease in ________ traits
maladaptive
J. Losos performed an experiment on lizards that colonized islands. What genus? What did he find?
- Anolis - Larger diameter perch branches leads to longer hind limb -
What Augustinian monk discovered heritable discrete packets?
Gregor Mendel
What are some of the commonalities between Russel’s theory and Darwin’s theory?
- Organisms make like organisms - Variation btwn. individuals - Heritable traits - More offspring are produced
Natural selection acts on _______.
individuals
Gregor Mendel helped establish that there are alternate forms of genes: ______. And some prevent the __________ of others.
alleles expression
________ ________ among individuals in a population is a result of the combined effects of genes and environment.
Phenotypic variation
Adaptation by _________ to local environmental conditions in Potentilla glandulosa.
ecotypes
Bring plants from different places together, to grow them in the same environmental conditions.
Common Garden
Could a common garden experiment be done with animals?
It depends
Discuss the expected outcome of the P. glandulosa plant experiment and the actual outcome
- Plants will grow according to altitude
- But, all the plants grew different outside their home region
What was the deal with whitefish?
- It was discovered that there was Genetic Variation in Alpine fish.
- Whitefish move up into headwaters and became isolated
- Microsatellite DNA → populations are highly diverse and exhibit a high level of differentiation
What changes were discovered among Alpine (whitefish)?
Microsattelite DNA → diverse populations exhibit differentiation
What are the 5 factors to hold Hardy-Weinberg equilibrium?
- random mating
- no mutations
- large populations
- no immunology
- equitable fitness between all genotypes
Hardy-Weinberg states that allele frequencies will ______ ______ from generation to generation.
remain constant
What type of population distribution exists when the extreme phenotypes are selected against?
What does it prevent?
- Stabilizing selection
- Prevents changes in a population
What type of population distribution exists when 1 extreme is more represented?
Directional selection
What type of population distribution exists when 2 extremes are selected for?
What is the sciency word used to describe the distribution?
Disruptive Selection
Bimodal distribution
Can you have natural selection w/o heritability?
No
Is phenotype only based on genetics?
No, the enviornment has an influence on the organisms as well
What variable does heritabiliity equal?
h2
__________ change due to Natural Selection
Non-random
Natural selection can either favor, disfavor or ________ the genetic make-up of a population.
conserve
Adaptions that take place via natural selection depend on what?
Heritability of the trait
What is the formula for heritability?
What do the variables mean?
h2 = VG / VP
- h2 represents heritability
- VG represents genetic variance
- VP represents phenotypic variance
- Can also be expanded to include enviornmental variance: VP = (VG + VE)
Genetic Drift causes:
random allele frequency changes; especially in small populations
What correlation do you expect between population size and genetic diversity?
What example was used in class?
Positive correlation
Ledig (scientist) sampled populations of the chihuahua spruce in Mexico
What is an upside and downside to populations on an island?
- normally small population, so less variation for natural selection to act upon
- But, any new mutation is automatically in relatively high frequency, and will most likely have a better likelihood of being maintained
Inbreeding leads to higher extinction rates in small populations as well as:
- reduced fecundity
- depressed juvenile survival
- shortened life span
- small body size
Which study showed a positive correlation for inbreeding and extinction?
Glanville fritillaries
The result of natural selection is ________.
predictable
Genetic Drift results in ___________ changes.
unpredictable
________ vegetation influences stream temperature.
Riparian
The deeper the bodies of water, the _____ the temperature will change.
less
Most organisms do best in a _________ temperature range.
narrow
Discuss the rainbow trout research
-
2 forms of Actylcholinesterase; 1 for the cold temp. and 1 for the warm temp.
- serve a neural function
- A duplication event in rainbow trout has tweaked the second copy to improve the survivability of rainbow trout
Extreme temperatures ________ the rate of photosynthesis.
reduce
Why does high temperature reduce photosynthesis?
- ?
- ?
- When a plant is hot, they close the stomata to conserve water; but this prevents fresh CO2 from coming into the plant
- Enzymes are not in their optimal ranges
Physiological changes in response to temperature
(non-evolutionary, as this is over the life-span of an individual)
Acclimation
When an individual becomes more tolerant?
acclimation
Extreme cold loving marine bacteria
psychrophilic
In contrast to psychrophilic microbes, we might call these __________.
Give an example
Thermophilic
Thermus aquaticus
Body temperature changes with enviornment
Poikilotherms
Body temperature constant, regardless of enviornmental
homeotherms
Rely on external energy sources for heat
Ectotherms
Rely on metabolic energy for heat
Endotherms
Desert plants must _______ heat storage.
reduce
How do Arctic and Alpine plants stay warm?
increase radiative heating
decrease convective cooling
How do Tropic Alpine Plants stay warm? (2 things)
- Retain dead leaves to insulate
- Thick pubescence
How do Liolaemus lizards thrive in cold enviornments?
- ?
- ?
- ?
- burrows
- dark pigmentation
- sun basking
How can grasshoppers acclimate themselves to temperature?
adjust varying intensity of pigmentation [melanin] during development
range of enviornmental temperatures over which metabolic rate of homeothermic animal does not change
Thermal neutral zone
What happens when outside the thermal neutral zone?
enviornmental stress and death may occur
In what enviornment would you expect a wide range of temperature/ climate?
a) tundra
b) tropical rain
c) tropical savannah
a) tundra
How are big ‘ol sharks endothermic?
they have countercurrent arteries and veins; blood away from the heart is warming incoming blood from muscles
How can lil ‘ol bumblebees generate heat for themselves?
Are they ectotherms or endotherms?
- they leave their wings in one place, but use the muscles w/in the wings to generate heat
- they are generally ectothermic, but can perform endothermic activity
What state can hummingbirds get into when food is scarce?
torpor
Primary ways to avoid the extreme?
- inactivity in a shelter
- reducing metabolic rate
What are 2 ways to reduce metabolic rate?
- Hibernation (long-term) or torpor (short-term)
- Estivation during hot,dry times
Microclimates affect the ______ experience
individual
The performance of individuals varies with ___________.
temperature
Some organisms are adapted to survive the extremes, and some ________ the extreme.
avoid
Large scale weather variation
Macroclimate
Smal scale weather variaiation
Microclimate
3 important properties of water:
- Specific Heat Capacity of water - absorbs heat w/o changing temp.
- Latent Heat of Evaporation - cools things
- Latent Heat of Fusion - as it freezes
What are 3 ways a desert plant can reduce it’s heat storage?
- Decrease heating via conduction
- Increase convection cooling
- Reduce radiative heating