Chap 5: Evolution of Biodiversity Flashcards
To measure species diversity at local or regional scales, scientists have developed two measures:
1. ____
2.____
- Species richness and
- Species evenness.
True or false
The higher the value of Shannon’s Index (H), the higher the diversity.
True
Which is used to calculate Shannon’s Index of diversity?
I: The proportion of individuals in each species
II: The total number of species
III: The number of individuals in each species.
a) I only
b) I and II
c) II only
d) I, II and III
b)
To calculate this index, we must know the total number of species in a community (n) and, for ezch speices, the proportion of the individuals in the community that represent that species (p).
FIl the blanks.
An ecosystem has high ____ _____ if it’s species are all represented by similar numbers of individuals.
Species evenness.
The relatedness of the species in a phylogeny is determined by ______ _ ___
similarity of traits:
The more similar the treits of two species, the more closely related the two species are assumed to be.
Evolved resistance to a pesticide is an example of:
a) a non-adaptative process
b) the botteneck effect
c) natural selection
d) artificial selection
d) Artificial selection
If such a mutation is passed along to the next generation, it adds new _____ to the population.
GENETIC DIVERSITY
Evolution can also occur by random, nonadaptive, processes.
Name the five random, non-adaptative processes that can change the genetic composition of a population over time :
- Mutation
- Gene flow
- Genetic drift
- Bottleneck effect
- founder effects
Evolution can occur throught random processus. Name the process illustrated here:
Gene Flow
Gene flow can be helpful in bringing in genetic variation to a population that lacks it.
Evolution can occur throught random processus. Name the process illustrated here:
Genetic drift
In a small population, some less-common genotypes can be lost by chance as random matin amoung a small number of individuals can result in the less-common genotype not mating.
Genetic drift is less likely in a big population.
Using this figure, explain the bottleneck effect
If a population experiences a drastic decrease in size (goes through a “bottleneck”, some genotypes will be lost, and the genetic composition of the survivors will differ from the composition of the original group.
Using this figure, explain the founder effect.
If a few individuals from a mainland population colonize an island, the genotypes on the island will represent only a subset of the genotypes present in the mainland population. As with the bottleneck effect, some genotypes will not be present in the new population.
Identifie and explain the speciation process illustrated:
Allopatric speciation of Darwin’s finches.
In the Galapagos Islands, allopatric speication has led to a large variety of finch species, all descended from a single species that colonized the islands form the South American mainland.
Identify the 2 processes that cause genetic diversity
Every individual has a genotype that, in combination with the environment, determines it’s phenotype. In a population, genetic diversity is produced by the processes of mutation and recombination.
Explain how environmental change can cause species extinctions
When environmental changes are too rapid and too extensive to permit evolutionary changes, or if a species is unable to move to more hospitable environments, a species will not be able to persist and will go extinct.
Fill the blank
Artificial selection select for specific traits that tend toward a _____ _____.
Natural selection favors any combination of traits that improves an ______ ______ - it’s ability to survive and reproduce.
- Predetermined goal
- Individual’s fitness
List the 5 Anthropogenic causes of the sixth mass extinction
Habitat destruction
Overharvesting
Introduction of invasive species
Climate change
Emerging diseases.
Fill the blank
Every species has a range of tolerance for the ____ conditions of the environment.
abiotic
Fill the blanks
The conditions under which a species can survive, grow, and reproduce is known as it’s _____ _____
fundamental niche
Fill the blank
The portion of the fundamental niche that a species acutally occupies due to biotic interactions, including predation, competition and disease, is known as _____
realized niche
Fill the blank
The niche a species occupies determines it’s _____
distribution
True or false
Evolution can produce adapted populations more easily when environmental changes are slow rather than rapid.
True.
