14.1 Define and distinguish between microevolution and macroevolution. microevolution : the changes over time in allele frequency in a population.
macroevolution : the broader pattern of evolutionary change over long periods of time including speciation .
14.2 Compare the definitions, advantages, and disadvantages of the different species concepts.
Species
Concept definition advantages
Biological
A group of populations whose members have the potential to interbreed in nature and produce fertile offspring.
Using reproductive isolation as the sole criteria is straightforward.
Morphological
Ecological
Based on observable and measurable physical traits such as shape, size, and other features of morphology (form).
Focuses on niches and unique adaptations to particular roles in a biological community.
Most common.
Can be applied to asexual organisms and fossils.
May look similar but distinguishable based on diet and location in environment.
Phylogenetic
The smallest group of individuals that shares a common ancestor and that forms one branch on the tree of life.
History is traced by comparing its characteristics, such as morphology or DNA sequences, with those of other organisms.
14.3 Describe five types of prezygotic barriers and three types of postzygotic barriers that prevent populations belonging to closely related species from interbreeding. table 14.3 p. 280 disadvantages
A. Extinct organisms with only fossil evidence.
B. Useless for prokaryotes
(asexual)
Relies on subjective criteria.
Requires close examination of behavior and habitat.
Agreeing on the amount of difference required to distinguish separate species remains a problem.
Mrs. Loyd
 cloyd@waukee.k12.ia.us
Page 1 of 3 http://loydbiology.weebly.com
4/15/2020 http://www.mybiology.com

14.4 Explain how geologic processes can fragment populations and lead to speciation.
Allopatric Speciation: “In another place”
14.5 Explain how sympatric speciation can occur, noting examples in plants and animals.
Sympatric Speciation: A new species arises within the same geographic area as a parent species.
Polyploidy:
 genetic isolation by hybridization + failure at cell division.
 Less likely than the other two.
Habitat differentiation :
 subgroups of original population evolved adaptations for exploiting different food sources.
 If in different habitats, mating between the two specializing populations would become rare, isolating gene pools.
Sexual selection :
 Females choose based on different factors.
14.10 Describe the circumstances that led to the adaptive radiation of the Galapagos finches.
Adaptive Radiation : The evolution of many diverse species from a common ancestor. Example: Darwin’s Finches
Typically occurs when a few organisms colonize new, unexploited areas or when environmental changes cause numerous extinctions, opening up a variety of opportunities for the survivors.
 Example:
 Extinction of dinosaurs.
 Many niches opened up.
 Mammals underwent dramatic adaptive radiation.
Isolated Island chains with physically diverse habitats are often the sites of explosive adaptive radiations.
 Colonizers may undergo multiple allopatric and sympatric speciation events
 Producing species that are found nowhere else on Earth o Example:
 Galapagos Archipelago

Great showcase of adaptive radiation
 Each island produced by volcanic activity
 Ocean currents and winds brought stray plants, animals, microorganisms.
Mrs. Loyd
 cloyd@waukee.k12.ia.us
Page 2 of 3 http://loydbiology.weebly.com
4/15/2020 http://www.mybiology.com

14.11 Compare the gradualism model and the punctuated equilibrium model of evolution. Explain how each model applies to the fossil record.
Punctuated: many fossils appear suddenly in fossil record and then…
Equilibria: persist essentially unchanged through several layers (strata) until…
Punctuated: disappearing as suddenly as they appeared.
One would not expect many transitional fossils in the record.
Punctuated Equilibrium
Gradualism:
 Other fossil species appear to have diverged gradually over long periods of time.
 Differences gradually evolve in populations as they become adapted to their local environments
Gradualism
Mrs. Loyd
 cloyd@waukee.k12.ia.us
Page 3 of 3 http://loydbiology.weebly.com
4/15/2020 http://www.mybiology.com