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Chapter 22: Objectives
1) State the two major points Darwin made in The Origin of Species concerning the
Earth's biota.
Species evolved from ancestral species and were not specially created. Natural
selection is a mechanism that could result in this evolutionary change.
2) Describe Carolus Linnaeus' contribution to Darwin's theory of evolution.
He adopted a system for grouping species into categories and ranking the categories into
a hierarchy.
3) Describe Jean Baptiste Lamarck's model for how adaptations evolve.
The “law of use and disuse” Whatever is in constant use becomes bigger and
stronger, but if those body organs are not in use they deteriorate.
4) Explain what evidence convinced Darwin that species change over time.
5) Explain why variation was so important to Darwin's theory.
Because as time goes on more and more members of the population resemble the better
competitors, while fewer resemble the poorer competitors. Over time, this will change the
gene pool the result is evolution.
6) Define and state the basic principles in natural selection.
Each species produces more offspring than can survive. These offspring compete with
one another for the limited resources available to them. Organisms in every
population vary. The offspring with the most favorable traits or variations are
most likely to survive and therefore produce more offspring.
7) Using some contemporary examples, explain how natural selection results in
evolutionary change.
As time goes on the same kind of people will compete for the same resources
that make allow them to survive. Then competition occurs and finally survival of
the fittest will occur.
8) Describe how molecular biology can be used to study the evolutionary
relationships among organisms.
Scientist examines the nucleotide and amino acid sequences of different organisms.
Organisms that are closely related have a greater proportion of sequences in common
than distantly related species.
9) Explain the problem with the statement that Darwinism is "just a theory".
Chapter 23: Objectives
1. Explain what is meant by the "modern synthesis".
Genetics being incorporated into evolutionary thinking, creating a new, more
comprehensive view of evolution.
2. Explain how microevolutionary change can affect a gene pool.
Due to microevolutionary change there might be more variation between populations in
the physical and individual characteristics.
3. In their own words, state the Hardy-Weinberg theorem.
As long as there is only mating and reproduction, the alleles in a population will remain
constant.
4. Describe the usefulness of the Hardy-Weinberg model to population geneticists.
5. Explain how genetic drift, gene flow, mutation, nonrandom mating and natural
selection can cause microevolution.
Genetic Drift can increase or decrease the randomness of alleles. Gene Flow can
introduce or remove alleles from the population when individuals leave or enter a
population. Mutation can randomly change the DNA. Nonrandom mating can interbreed
mates with relatives or cause a sexual selection. Natural selection can increase the allele
frequency due to the impact of the environment.
6. Distinguish between the bottleneck effect and the founder effect.
Founder effect occurs when allele frequencies in a group of migrating individuals are, by
chance, not the same as that of their population of origin. On the other hand, the
bottleneck effect occurs when the population undergoes a dramatic decrease in size.
7. Explain why mutation has little quantitative effect on a large population.
8. Give the cause of nearly all genetic variation in a population.
Mutations, sexual reproduction, diploidy, outbreeding, balanced polymorphism.
9. Explain how genetic variation may be preserved in a natural population.
10. Describe what selection acts on and what factors contribute to the overall fitness
of a genotype.
11. Give examples of how an organism's phenotype may be influenced by the
environment.
12. Distinguish among stabilizing selection, directional selection and diversifying
selection. Stabilizing selection eliminates individuals that have extreme or unusual traits,
and the individuals with the more common traits are the best adapted. Directional
selection favors traits that are at one extreme of a range of traits, meaning that traits at the
opposite extreme are selected against. Diversifying selection occurs when the
environment favors extreme or unusual traits, while selecting against the common traits.
13. Give at least four reasons why natural selection cannot breed perfect organisms.
1- Structures result from modified ancestral anatomy.
2- Adaptations are often compromises.
3- The gene pool can be affected by genetic drift.
4- And natural selection can act only on available variation.
Chapter 24: Objectives
1) Define biological species (E. Mayr).
2) Describe some limitations of the biological species concept.
3) Distinguish between prezygotic and postzygotic isolating mechanisms.
Prezygotic: mechanisms that prevent fertilization. Postzygotic: mechanisms that prevent
the formation of fertile offsprings.
4) Describe five prezygotic isolating mechanisms and give an example of each.
Habitat: live in separate habitats. Behavioral: posses’ unique, exclusive mating signals
and courtship behavior. Temporal: breed at different times. Mechanical: have
anatomically incompatible reproductive organs. Gametic: have incompatible sex cells.
5) Distinguish between allopatric and sympatric speciation.
Allopatric speciation is the division of a population because of geographic barriers so that
interbreeding between the two resulting populations is prevented. Sympatric speciation is
the formation of new species without the presence of a geographical barrier.
6) Describe the adaptive radiation model and use it to describe how it might be
possible to have many sympatric closely related species even if geographic isolation
is necessary for them to evolve.
Adaptive radiation is the rapid evolution of many species from a single ancestor. This
happens when the ancestral species colonize areas with diverse geographic or ecological
conditions. Variations of the ancestral species become populations specialized for each
set of conditions.
7) Define sympatric speciation and explain how polyploidy can cause reproductive
isolation.
I know the definition of sympatric speciation. Polyploidy is the possession of more
than the normal two sets of chromosomes found in diploid cells. Normal meiosis
in the tetraploid individual will continue to produce diploid gametes, reproductive I
solation with other individuals in the population occurs in a single generation.
8) List some points of agreement and disagreement between the two schools of
thought about the tempo of speciation (gradualism vs. punctuated equilibrium).
Chapter 26: Objectives
3. Provide evidence to support the hypothesis that chemical evolution resulting in
life's origin occurred in 4 stages:
a. Abiotic synthesis of organic monomers
b. Abiotic synthesis of polymers
c. Formation of protobionts
d. Origin of genetic information
4. Describe Whittaker's five-kingdom system.
5. Describe three alternatives to the five-kingdom system and explain the rationale
for each.