Selection
The mode of natural selection that is most likely to contribute to speciation.
Disruptive selection
What three things are required for evolution to occur on a population? Describe/define each of them.
What do you call a group of individuals of the same species who are living in the same area at the same time?
Population
A community along with its physical environment is called what?
An ecosystem
Define the intermediate disturbance hypothesis.
Intermediate amounts of disturbance lead to higher biodiversity, and low and high amounts of disturbance lead to lower biodiversity.
Which mode of selection changes the average value of a trait?
Directional selection
Which evolutionary mechanism results in adaptation?
Natural selection
Which source of genetic variation does not promote speciation? Why?
Gene flow: Gene flow is the flow of genes between different populations. This reduces speciation because it is making the populations more similar to each other.
Any change in allele frequencies in a population that is due to chance.
Genetic drift
This trophic level uses solar energy or chemical energy contained in reduced inorganic compounds to manufacture their own food.
Primary producers
Long necks make it easier for giraffes to reach leaves high on trees, while also making them better fighters in “neck wrestling” contests. Neck size is genetic. Which mode of selection applies here? Why?
Directional selection: Longer necks have higher fitness, small and medium sized necks have reduced fitness.
The fossil record provides more information about ancient cockroaches than about recent walking-stick insects. This is an example of which type of bias?
Temporal bias
What is the difference between a fundamental niche and a realized niche?
What is succession?
The changes in species composition within a community after a disturbance
True or false: All traits of organisms are adaptations. Justify your answer.
False. Traits can be neutral to an organism (like vestigial traits) or traits can happen due to genetic drift and be random rather than adaptive.
Women often have complications during labor while giving birth to very large babies, whereas very small babies tend to be underdeveloped. Which mode of selection is most likely at work regarding the birth weight of babies?
Stabilizing selection
Name and describe at least 4 pieces of evidence that support the theory of evolution.
1. Geologic time
2. Extinction events
3. Transitional features
4. Fossils
5. Vestigial traits
6. Direct observations
7. Homology
8. Biogeography
Give an example of a scenario where energy and nutrients would move from a decomposer to a higher trophic level.
Ex. a robin eating an earthworm
What does it mean if an organism has high fitness?
They have a high number of surviving and fertile offspring relative to others in their population.
List two biotic factors that could affect the distribution of species, and explain how they would affect distribution.
True or false: Natural selection produces organisms perfectly suited to their environments. Justify your answer.
False. Natural selection will not produce perfect traits. Natural selection can only act on the available genetic variation within a population, it cannot create new perfect traits.
Give an example of structural homology.
Vertebrate limb (one big bone, two smaller bones, lots of little bones)
Soon after the island of Hawaii rose above the sea surface (somewhat less than one million years ago), the evolution of life on this new island should have been most strongly influenced by which source of differential reproduction?
List three abiotic factors that could affect the distribution of species, and explain how they would affect distribution.
In wild horse populations, young males are not allowed to live in their herd after they reach a certain age. Thus, young bachelor stallions will roam together with other bachelors until they are able to secure mares of their own and establish their own herd. What genetic event is occurring in this situation?
Gene flow