AP Environmental Science › Natural Selection
An organism's fitness, as it applies in natural selection, involves __________.
the number of their offspring that reproduce themselves
the number of mates with whom they reproduce
the efficiency with which they hunt
their ability to chase prey for extended periods of time
In natural selection, the term fitness means how successful the organism is in reproducing. If an organism has a large amount of offspring, but lives half as long as its similar organisms, it is still more successful because its genes will be apart of more offspring, who will reproduce themselves.
What is the term for the formation of new species through the course of evolution?
Speciation
Bottleneck effect
Fecundity selection
Allele frequency
Speciation is the term for formation of new species throughout the process of evolution. Isolated groups might split off from a species to become an entirely different species. This could be caused from changes in selection pressures, mutations, or genetic drift.
What two factors determine biological fitness?
Survival and reproductive rate
Survival and size
Allele frequency and genetic diversity
Genetic diversity and age of first reproduction
Genetic diversity and population size
The correct response is survival and reproductive rate. These are the two factors that are used to determine the fitness of an individual. There are other variables that can impact survival and reproduction rate, but these are the two foundational factors that impact fitness.
Fitness = Rate of Survival times Rate of Reproduction
Thus, if an individual lives to be 100 years old but has 0 children, then their overall fitness is 0. (Fitness = 100 x 0 = 0)
Evolution occurs through a process called natural selection.
What are the four premises or observations of natural selection?
High reproductive rate, inherited variation, rapid population growth, and differential reproductive success
High reproductive rate, adaptation, rapid population growth, and differential reproductive success
High reproductive rate, inherited variation, mutation, and differential reproductive success
High reproductive rate, inherited variation, rapid population growth, and modern sythesis
Populations, inherited variation, rapid population growth, and differential reproductive success
Adaptation, modern synthesis, and mutation are all part of evolution through natural process. Adaptation is the process of inheritable traits being carried from one generation to the next. Modern synthesis is the combining of Darwin's theory of evolution with modern principles of genetics. Mutations are changes in genes and are part of the modern synthesis.
What is the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment?
Phenotype
Nomenclature
Haploid
Genotype
The phenotype is described as the observable characteristics of an organism. Natural selection is based on survival of the fittest due to differences in phenotype. This is not to be confused with genotype, which is the genetic (DNA sequence) of a trait.
In a particular habitat, Species A competes with Species B for food resources. Which type of competition is this?
Interspecific exploitation competition
Intraspecific exploitation competition
Interspecific interference competition
Intraspecific interference competition
Interspecific competition is that which occurs between two different species. Exploitation competition involves the two groups of organisms competing for a limited resource, which may or may not involve direct contact between the species. Interference competition involves direct contact between organisms.
A new predator, the red-tailed hawk has been introduced to a meadow ecosystem with several rodent species with varying behaviors and characteristics. Hawks hunt by day, swooping down into areas without dense foliage and grabbing their prey by surprise. Which species are most likely to decline by introducing this top predator?
Voles that forage for seeds during the daytime in fields and meadows.
Gophers that burrow underground and forage for roots and insects.
Field mice that are nocturnal and forage for seeds in open meadows.
Shrews that forage for seeds and insects in wooded areas under leaf litter.
Brown Rats that much prefer foraging in dumpsters and other human sources of food than foraging in the wild.
Since voles not only forage in open grassland and meadows where hawks hunt their prey, they also forage during daylight hours, when hawks are most active. Therefore, the vole population is most likely of all the rodent species to see a significant decline.
__________ is responsible for the idea of natural selection.
Charles Darwin
Ronald Fisher
Empedocles
Jean-Baptiste Lamarck
The modern theory that is natural selection is from the studies of Charles Darwin. His theory of natural selection was an explanation for the adaptation of species. He further explored his ideas in his book, The Origin of Species.
"Survival of the fittest" is often used to describe Darwin's theory of natural selection; however, which of the following choices better describes the theory of adaptation by natural selection?
"Survival of the most adaptable"
"Survival of the biggest"
None of these
"Survival of the most impressive"
Individuals that are "fit" in regard to natural selection does not refer to strength or one particular trait. Rather, it refers to an organism’s adaptability to their environment, which allows them to survive and reproduce. Successful reproductive events pass on genes, traits, and adaptations to future generations of the species.
Which of the following is an example of an initial step associated with natural selection?
Ash from the industrial revolution darkens the tree trunks in a moth species' habitat, the dark moths are favored and light moth populations are reduced.
An ancient, short-necked giraffe stretches its neck to reach higher leaves and its offspring inherit a long neck.
A Chihuahua breeder singles out the smallest individuals from each litter of puppies and breeds them together to produce smaller puppies.
None of these
All of these
One of the initial steps towards natural selection is environmental change that selects for or against a particular trait in a species (e.g. ash darkening habitats selects for darker colored moths). Over time, as the ash continues to color the moths' habitat, the light moths—being more visible to predators—will die out. As a result their reproductive success will be reduced and the darker moths will be more likely to reproduce and pass on their traits.