Download Evolution and Natural Selection Notes Outline

Evolution and Natural Selection Notes Outline
Chapter 15
NCSCOS – 3.05
A. (15.1)Evolution and Natural Selection
a. Charles Darwin employed as naturalist on the ________________ in the 1830s
b. The ship traveled to the ________________________
c. Darwin made many observations of plant and animal life
d. Darwin began to theorize that organisms ______________________ (evolution)
e. He then proposed a ________________________= NATURAL SELECTION
B. Natural Selection
a. Based on the fact that there is_________________ in every population
b. Variation is controlled by genes (inherited)
c. Some variations better enable an organism to ______________________ =
______________________
d. Those organisms that are most well adapted to their environment should survive
and reproduce more successfully (passing on those desired traits) than those
organisms that do not possess those adaptations and are not as successful at
survival and reproduction
e. Therefore there should be an
__________________________________________________________________
______(most well adapted) and a decrease in the frequency of the organisms that
are not well adapted over many generations
C. Evidence for Evolution
a. Structural adaptations
b. Batesian Mimicry:
___________________________________________________________
c. Mullerian Mimicry – multiple
___________________________________________________________
d. Physiological adaptations – bacteria develop
______________________________ – MRSA, C. dificile
e. Fossil record
f. Biochemistry – study s__________________________________, DNA
sequences to determine degree of relatedness
g. Vestigial structures – _________________________________________ – eyes
in cavefish, etc.
D. (15.2) Mechanisms of Evolution
a. ___________________________________________
b. An individual cannot alter its phenotype based on environmental pressures
c. Evolution occurs because there is ______________________in a population
d. These variations are at the ___________________________ and are expressed as
different phenotypes
e. Organisms that possess phenotypes for traits that give them a
____________________________ (well adapted) are more likely to survive,
reproduce and pass the alleles for those traits on
f. Beneficial alleles ____________________________________ over many
generations, non-beneficial alleles decrease
g. Organisms that possess phenotypes for traits that give them a survival advantage
(well adapted) are more likely to survive, reproduce and pass the alleles for those
traits on
h. Gene pool = _________________________________________
i. Non-evolving populations are at _______________________
j. Changes in allelic frequencies = ____________________
k. Can be random – ________________________ (evolution by chance events) or
can be caused by natural selection
l. Natural selection moves evolution in a specific direction:
• Stabilizing selection –
________________________________________________________
• Directional selection: one ________________________of a trait is
selected for – woodpeckers
• Disruptive selection – either of two extremes selected for – limpets
• Speciation – evolution can occur to the point that members of a
population evolve so much that they can
_______________________________ with the rest of the population.
They have evolved into a new species. Can be caused by geographic or
reproductive isolation
m. Two theories for rate of evolution –
• Gradualism – slow and steady change
• Punctuated equilibrium – long periods of stability interrupted by short
bursts of change
n. Patterns of evolution –
• Divergent evolution (adaptive radiation) –
____________________________________________________ that each
occupy a different niche
• Convergent Evolution – different and unrelated species in different parts
of the world evolve ____________________________ because they
occupy similar habitats