CH. 24 STUDY GUIDE: THE ORIGIN OF SPECIES
KEY WORDS
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species
subspecies
anagenesis
cladogenesis
cline
subspecies
races
speciation
microevolution
macroevolution
phylogeny
prezygotic isolating mechanisms
geographic isolation
ecological(habitat) isolation
temporal(seasonal) isolation
behavioral isolation
mechanical isolation
gametic isolation
postzygotic isolating mechanisms
developmental isolation
hybrid inviability
hybrid sterility
allopatric speciation
sympatric speciation
polyploidy
evolutionary bottleneck
punctuated equilibrium
gradualism
Geologic time chart
index fossils
radioactive dating
phylogeny
systematics
convergent evolution
DNA hybridization
molecular clock
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WORD ROOTS
allo - = other; - metron = measure (allometric growth: the variation in the relative rates of growth of various parts of the body, which helps shape the organism)
ana - = up; - genesis = origin, birth (anagenesis: a pattern of evolutionary change involving the transformation of the entire population, sometimes to a state different enough from the ancestral population to justify renaming it as a separate species)
auto - = self; poly - = many (autopolyploid: a type of polyploid species resulting from one species doubling its chromosome number to become tetraploid)
clado - = branch (cladogenesis: a pattern of evolutionary change that produces biological diversity by budding one or more new species from a parent species that continues to exist)
hetero - = different (heterochrony: evolutionary changes in the timing or rate of development)
macro - = large (macroevolution: evolutionary change on a grand scale, encompassing the origin of novel designs, evolutionary trends, adaptive radiation, and mass extinction)
paedo - = child (paedomorphosis: the retention in the adult organism of the juvenile features of its evolutionary ancestors)
post - = after (postzygotic barrier: any of several species-isolating mechanisms that prevent hybrids produced by two different species from developing into viable, fertile adults)
sym - = together; - patri = father (sympatric speciation: a mode of speciation occurring as a result of a radical change in the genome that produces a reproductively isolated subpopulation in the midst of its parent population)
QUESTIONS
- Give a biological definition of species.
- Explain the geographic isolation model of speciation, in doing so take into account the roles of mutation, natural selection, and the gene pool.
- How are speciation and microevolution different?
- Distinguish between extrinsic and intrinsic isolating mechanisms.
- Describe speciation by polyploidy.
- Explain what is meant by adaptive radiation, and discuss the evidence for this phenomenon.
- What factors have contributed to the adaptive radiation of the thousands of endemic species of the Hawaiian Archipelago?
- Compare the hypotheses of gradualism and punctuated equilibrium, and give an example supporting each hypothesis.
- Explain why the modern concept of the species is difficult to apply to sexual organisms, fossil organisms, populations at an intermediate stage of divergence, and allopatric populations.
- Darwin and Wallace both came up with a theory of evolution at approximately the same time. Explain how the time was right for these two men to come up with the same theory at the same time.
- Describe the Darwin-Wallace theory of natural selection. What is meant by "survival of the fittest"?
- Why is it that only inherited changes are important in evolution?
- Discuss allopatric speciation.
- Give three definitions of biological evolution.
- Compare and contrast punctuated equilibrium and gradualism. How would you support your favorite theory?
- Does evolution produce "perfect" organisms?
- Give examples of reptilian structures that were exaptations for flight in birds.
- Define, discuss and give an example of how each of the following isolating mechanisms contributes to speciation in organisms.
- Geographical barriers
- Ecological (including seasonal) isolation
- Behavioral isolation
- Polyploidy
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