Limits of Life
(abiotic, biotic, history)
(abiotic, biotic, history)
What is the 10% rule?
Only 10% of the total energy produced at each trophic level is available to the next level. The amount of energy passed up to the levels of the food pyramid reduces as you go up.
Which of the following is a modern definition of biological evolution?
A change in allele frequencies in a population over time
True or false: Natural selection gives acts for the good of the species
False: Natural selection does not have a goal in mind. The organisms with higher fitness survive and reproduce.
Which mode of natural selection is most likely to contribute to speciation?
A. directional selection
B. stabilizing selection
C. disruptive selection
D. balancing selection
C. disruptive selection
We discussed the 5 characteristics that organisms share. In addition to being made of cells, all organisms...(2pts)
A. process information
B. reproduce sexually
C. acquire and use energy
D. have a nucleus
E. are made of cells
A. process information
C. acquire and use energy
E. are made of cells
The feeding relationships among the species in a community determine the community's _____.
A. species-area curve
B. species richness
C. trophic structure
D. secondary succession
E. ecological niche
C. trophic structure
What must be true of any organ described as vestigial?
A. it must be analogous to some feature in an ancestor
B. it must be homologous to some feature in an ancestor
C. it must be homologous and analogous to some feature in an ancestor
D. it need be neither homologous nor analogous to some feature of an ancestor
B. it must be homologous to some feature in an ancestor
Biological fitness is best defined as
A. a heritable trait that increases the match of an individual to its environment.
B. variability in the population for a trait that increases survival.
C. the ability of an individual to produce offspring that survive and reproduce, relative to other individuals in the population.
D. competition among individuals for resources that allow them to have more offspring.
E. similar reproductive success among individuals in a population.
C. the ability of an individual to produce offspring that survive and reproduce, relative to other individuals in the population.
Most Swiss starlings produce four to five eggs in each clutch. Starlings producing fewer or more than this have reduced fitness. Which of the terms best describes this situation?
A. directional selection
B. stabilizing selection
C. disruptive selection
D. balancing selection
B. stabilizing selection
Describe the difference between a fundamental niche and a realized niche
A fundamental niche describes the full range of environmental conditions/resources a species could use without competitors, while a realized niche is the actual portion of the full range the species occupies due to limitations like competition or other limiting factors.
What type of species interaction would this be?
Lions and hyenas both share the same resource of food (zebras). The lions on average manage to hunt more zebras than the hyenas.
Competition
Which is an example of structural homology?
A. the same group of embryonic cells forms the adult jaw of a perch and of a dog
B. vertebrate forelimbs generally have the same number and a similar arrangement of bones
C. all vertebrate embryos form pharyngeal puches
D. all organisms share a common genetic code
B. vertebrate forelimbs generally have the same number and a similar arrangement of bones
In nature, females often do not mate at random but rather actively choose certain males based on certain characteristics. In some species, males even compete to gain a female’s attention. What is this type of selection
most specifically called?
Sexual selection
Genetic variation ________.
A. is created by the direct action of natural selection
B. arises in response to changes in the environment
C. must be present in a population before natural selection can act upon the population
D. tends to be reduced by when diploid organisms produce gametes
C. must be present in a population before natural selection can act upon the population
Give an example of a hypothesis and prediction.
Example:
Hypothesis: nutrient availability is a limiting factor in duckweed growth
Prediction: the cups with higher concentrations of fertilizer will grow more than cups with lower concentrations
Give an example of how biotic and abiotic factors can influence the process of evolution
Ex. The abiotic factor could be the cold climate of Antarctica that is being changed by global warming. The biotic factor could be that penguins are competing for nesting locations because of rising water levels. The competition for nesting locations could influence natural selection in that the penguins that nest earlier and avoid the thaw would be fitter and have surviving offspring. Over time the frequency of early nesting penguins could increase.
Which of the following are supported by evidence from the fossil record? Check all that apply.
A. The concept that species can go extinct.
B. The hypothesis that individuals evolve by acquiring new traits.
C. The idea that the Earth is 4.6 billion years old.
D. The existence of transitional forms.
A. The concept that species can go extinct.
D. The existence of transitional forms
Explain why genetic drift said to be a random process, but natural selection is not considered random.
Genetic drift is random because the allele frequencies shift due to chance events such as disease, isolation of populations, or other reasons. Natural selection is non-random because allele frequencies change due to differential reproductive success where certain traits make individuals more or less fit. Genetic drift would be like the stepping on a population of brown and green bugs. The ones that die due to the shoe are random and their coloration had nothing to do with their survival there may happen to be more brown bugs after the shoe but it is random.
List all three modes of selection and how they each affect genetic variation.
Directional: Form of natural selection in which the entire curve moves, genetic variation decreases
Disruptive: form of natural selection in which a single curve splits into two higher ends, increases genetic variation
Stabilizing: form of natural selection by which the center of the curve remains in its current position but condensed, decreases genetic variation
How can gene flow benefit populations? How can it harm populations?
Gene flow can introduce more genetic variation into a population with immigrating organisms but can decrease genetic variation with emigrating organisms. Also the alleles introduced by gene flow may not always increase a population's fitness. A well adapted species could decrease in fitness due to gene flow making them more similar to a less well adapted species.
Name one factor that affects climate at the regional scale and describe/define HOW it affects climate.
Ex. Mountain ranges affect climate at the regional scale because they cause rain shadows. The rain shadows mean that air with a lot of moisture from an ocean facing side is forced upward by the mountain, cools, condenses, and precipitates on that side of the mountain. The dry air then descends over the other side of the mountain and warms up. The two sides of the mountain have different climates because of the rain shadow: one side ins wet, while the other is dry affecting what organisms can thrive on either side.
Name and explain the biases of the fossil record.
Habitat bias: environment with sediment piling up, not too much competition
tissue/taxonomic bias: shells and hard body parts
temporal bias: older = higher chance of being broken in Earth's crust, too young = fossils take a while to be made
abundance bias: more organisms = higher chance of finding fossils of them
Explain how more than one type of selection can influence a species over its evolutionary history
Ex. Both artificial and natural selection can occur in a species. For example the zebrafish from lecture experienced both artificial selection and natural selection as they were chosen by the scientist to be "brave" or "shy" and also naturally were inclined or not inclined to reproduce in a laboratory setting. The fish that survived and reproduced viable offspring depended on human's selecting and nature selecting to produce more distinct "brave" and "shy" populations.
Name the four sources of gene variation
mutation, gene duplication, sexual reproduction, gene flow
What is the difference between Darwinian evolution and Lamarckian evolution?
Lamarck believed that species changed because of acquired traits from their parents. In his model giraffes having long necks is because previous generations stretched their necks more and more to reach food until they have the necks we're are familiar with today. The issue is his theory is based on the idea of evolving with a goal in mind and also all physical traits being heritable. That would be like a person having to amputate an arm having a child and the child only has one arm. Darwin popularized the idea of variation in a species and that the environment can only support so many organisms and therefore some organisms less suited to the environment don't survive/reproduce.