Macro
evolution
evolution
What is meant by fitness in relation to natural selection?
Fitness is an organisms ability to survive and reproduce.
Explain the difference between the genetic concept of a population and the ecological concept of a population.
Genetic population is defined by their ability to interbreed and the fact that live together.
Ecological population is defined by the functional role they play in their environment, their niche.
What is the difference between intra and inter specific interactions?
Intra specific is within one population (rabbits compete for food with rabbits).
Inter specific is community interactions (rabbits are eaten by coyotes) Two or more populations interacting.
Stabilizing: Push the population toward the middle ground phenotype
Disruptive: Push the population toward both extreme phenotypes
Direction: Push the population toward one extreme
Explain how a population can reach exponential growth.
If the biotic potential is high (high birth rate), then the rate of growth will be high, this will make the time is takes the double the population double very low and thus a population will double rapidly.
What is the definition of macroevolution?
Changes accumulate through the ages to produce organisms different enough to call them different families, orders, classes, phyla.
What are the three types of survivorship curves. Give an example of each.
Type I - Mortality is highest in the oldest members of the population (humans)
Type II- Their is the same chance of death for every age (hydra, squirrels)
Type III- Mortality is highest for the youngest members of the population (oysters)
List some ways that prey evade being eaten
Chase, camouflage, mimicry, herding, chemical defense, shell, spines, smell
What are the 5 agent of evolution?
1. Mutations
2. Migration
3. Genetic drift
4. Natural selection
5. Non-random mating
Explain how population dynamics and natural selection are related.
What is the definition of the evolution of a population?
Evolution of a population is the change in allele frequency in the gene pool.
What are some reasons for organisms to display clumped distrobution?
They clump around resources like water and food, they clump together for protection from predators, they clump together to find mates, and to not get lost.
What are the three types of symbiosis? Give an example of each.
Mutualism- hippo and bird
Commensalism- barnacles and whales
Parasitism- Leeches and humans
Use finches in the Galapagos islands to explain adaptive evolution.
When a finch population is blown out to the Galapagos islands they land on one of several unique ecosystems. The finches adapted to that ecosystem will survive to reproduce. Each ecosystem will allows finches with unique traits to reproduce. Over time the finches on each island will have adapted over generations to look different from each other.
What are the to kinds of limiting factors of population growth? Give examples.
Density dependent: space (breeding dens, nesting sites, sunlight (plants)), energy and nutrients, infectious disease, predation, parasitism, competition.
Density Independent: weather extremes- drought/flood, tornado, temperature extremes, forest fires, hard freeze. Human activities- pesticides, urbanization, agricultural applications.
Who's work influenced Darwin's development of natural selection. Explain
Thomas Malthus: Human population grows geometrically (supa fast), food production grows arithmetically (bro's a snail). Not enough resources to share. Darwin: It's the same for animals in nature so only the most competitive animals will survive.
Charles Lyell: Earth's features formed gradually over millions of years. Darwin: Maybe all species developed from one simple organism gradually over millions of years. (No divine intervention)
If a population pyramid has a large base and a very small peak what will happen to the population?
The population will grow since their is a large amount of organisms in the reproductive who will reach maturity and add to the population.
What kind of interspecific interaction is the green world hypothesis based on? How is it different from earlier views.
What is speciation? Give an example of it occurring
It is the evolutionary process of forming new species from pre-existing species. Reproductively isolated.
What is a carrying capacity and how does it affect population growth? (What kind of curve do we actually see?)
The carrying capacity of an ecosystem is the number of organisms of a particular species that an ecosystem can support or sustain. Environmental limits provide resistance which suppresses population growth so that is plateaus at the carrying capacity.
The struggle for survival:
– Biological organisms have more offspring than can possibly survive.
Inheritability:
– Biological organisms inherit some of their traits from their ancestors and pass them on to their descendants.
Variation:
– The inheritable traits of biological organisms vary, even within the same species. [Mutation & Sexual Reproduction]
Differential fitness:
– Some inheritable traits will be more advantageous than others in the struggle for survival.
Therefore, there has been and will continue to be, on average, a
(natural) selection of those organisms that have advantageous traits that will lead to the evolution of species.
Consider a closed population of 234 ducks. The birth rate is 50 and the death rate is 7. What will be the size of the duck population in two generations?
325 ducks
Birth rate - death rate, divide answer by population size. That's r (rate of growth)
Original population + r(original population) = new population
New population + r(new population) = final population (for 2 generations
Give an example of the Law of competitive exclusion in action.
Warbler's fill different niches in the trees of Maine because they cannot both use the same section of the tree and survive.
Some kinds of paramecium can coexist if one is in much smaller quantity, but other species only one can exist in the same location because it uses up all of the resources.
It is harder for bad bacteria to populate the human gut because good bacteria already use up the gut space and resources.
One example of evidence for natural selection is Endler's guppies. Explain what happened in his experiment.
Observation:
Low predator pool- bright guppies
High predator pool- drab guppies
Experiment: 2 pools. A- high predators. B low predators. Both pools start with equal amounts of bright and drab guppies
Results: Pool A- only drab guppies. Pool B- only bright guppies
K-selected life history: These populations have traits such as a type I survivorship curve to optimize the population size at the carrying capacity (k).
R-selected life history: These populations have traits such as a type III survivorship to maximize the growth rate of the population (r).