Download Evolution and Biodiversity

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Evolution and Biodiversity
I.
Types and Origins of Life
A. Major types of life on earth
1.
_______________ are the basis of life on earth
2.
Two major kinds of cells
a. prokaryotic—no nucleus, primitive, bacteria
b. eukaryotic—nucleus and internal structures
3.
Classification/Taxonomy
4.
a.
5 kingdoms:
b.
other taxonomic groups
c.
scientific names: the only ones that count
species—
B. How did life emerge on the primitive earth?
1.
a billion years of chemical evolution
2.
3.7 billion years of biological evolution, Fig 5-2
C. How do we know what was here in the past? Fig 5-3
1.
2.
3.
4.
II.
Evolution and Adaptation
A. What is evolution?
1.
a change in the genetic makeup of a ____________________ through
successive generations.
2.
a theory
2
3.
microevolution-small genetic changes that occur in the gene pool of a
population over time.
4.
macroevolution—long-term, large scale changes among groups of species,
including the formation of new species (____________________), loss of
species (____________________), and higher levels of evolution.
B. How does microevolution work?
1.
genetic information is carried in the sequences of the
________________ in ____________.
2.
_______________ are sequences of DNA that code for traits. They are
heritable.
3.
a population’s collection of genes is called a _____________________.
4.
Different forms of a gene are called ___________________, which are
randomly shuffled during ____________________.
5.
the raw material for microevolution is __________________________.
6.
4 things that drive microevolution
a.
mutation—random change in DNA structure of an INDIVIDUAL
1.
2.
3.
4.
5.
b.
gene flow—allows genes to move between populations
c.
genetic drift—random changes in gene frequency in small populations
d.
Natural selection—occurs when traits enable SOME INDIVIDUALS to
survive and produce more offspring
1. requires…
2. requires…
3. reproductive advantage occurs (differential reproduction)—ability
to…
4. advantageous alleles increase in frequency in successive populations
3
5. selective pressure—environmental conditions that lead to the
possibility of mutations being beneficial. A beneficial mutation is
called an….
7.
Types of natural selection
a. directional: “it pays to be ____________________” –environmental
conditions lead to allele frequencies at one end of the range of
variability to become more prevalent. Exemplified by the peppered
moth; modern day antibiotic resistance; giraffes
b.
Stabilizing: “it pays to be ____________________”—eliminates
individuals on the extremes of variability
c.
Diversifying/disruptive—“it doesn’t pay to be _________________”—
extremes are favored and the average is eliminated
C. Coevolution—when different species evolve together based on each other’s adaptations
III.
Adaptation and the Niche
A. What’s a niche and how do you pronounce it “What’s up, my…”
1.
2.
vs habitat: Where you live vs what you do
3.
fundamental vs realized: You’ve been lied to.
B. Generalists and Specialists
1.
generalist—
2.
specialist—
3.
which is better? It depends
C. Convergent evolution—because similar ecosystems present similar selective pressures,
similarities are observed between different taxonomic groups. For example:
D. Limits to adaptation: you’ll never be perfect (sorry)
1.
you can only have adaptations for a trait already in the gene pool
2.
adaptations are often compromises
3.
reproductive capacity
4.
other individuals w/o the trait also reproduce
4
IV.
Speciation, Extinction, and Biodiversity
A. speciation—when natural selection leads to the development of two species from one
B. Typically occurs in two steps, particularly in animals
1.
geographic isolation
2.
reproductive isolation
3.
Now natural selection can lead to two new species (divergent evolution)
C. Extinction
1.
2.
99.9%
3.
background extinction—
4.
mass depletion--
5.
mass extinction—25-70%
6.
adaptive radiation—evolution of numerous new species to fill the void created
by mass extinctions and depletions
D. Both speciation and extinction are affected by
1.
2.
3.
E. Modern day
F.
1.
B=S–E
2.
What are the projections of Wilson and Primm?
Evolutionary misconceptions
1.
2.
3.
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V.
The future of evolution
A. Artificial selection: pit bulls and red pears
B. Genetic engineering: fish genes in a tomato?
Inserting genes from one organism into the genes of another
Genetically modified organism (GMO) or transgenic organism
Fig 5-11
Saves time
Unpredictable
Creates controversy: Miracle or Menace?