SUMMARY of Theme 3: The origin story & A Brief History of Life on Earth (Topics 5-6)
EXPECTED OUTCOMES:
A) Understand the following B) Be able to define the C) Describe:
concepts: following terms: a. the importance of
a. gradualism a. fossil islands to the theory of
b. uniformitarianism b. microevolution evolution
c. bias in the fossil record c. macroevolution b. species isolating
d. continental drift d. reproductive mechanisms (pre &
e. descent with modification isolation postzygotic)
f. convergent evolution e. hybrid c. process of allopatric
g. natural selection f. sympatry speciation vs sympatric
h. relative fitness g. Selection types speciation
i. species (directional, d. the relationship
j. biological species concept stabilizing, and between natural
k. speciation disruptive) selection and different
l. adaptive radiation h. abiogenesis outcomes for hybrids in
m. hybridization i. protocells hybrid zones
n. reinforcement e. the scientific hypothesis
o. punctuated equilibrium. for how life on Earth first
p. Abiogenesis formed (4 steps)
A) Concepts:
a. Gradualism – evolution/speciation is a slow process by natural selectin that happens
over many generations.
b. Uniformitarianism - geologic processes have not changed throughout Earth's history.
“The present is the key to the past”
c. bias in the fossil record - refers to that not all life that has existed has fossilized, or if it
did fossilize, has been found. Therefore, there are gaps in the record.
d. continental drift – landmasses drift around on plates on hot mantle, and the relative
locations of landmasses have changed over time.
i. Consequences:
, 1. Change to the environment & climate = opportunities for diversification.
→ allopatric speciation
2. Mass extinctions
e. descent with modification - passing on of traits from parent organisms to their
offspring. Evolution!!
f. convergent evolution - Analogous traits are those that appear to be similar characters
but have not occurred as a result of common ancestry, but rather evolutionary
adaptations to similar environments.
g. natural selection - gives rise to adaptations. Selection of some individuals w/ certain
allele/characteristics over others because they’re better fit for survival & reproduction.
h. relative fitness – the ability for species w/ certain genes/characteristics to survive and
reproduce in an environment better than others.
i. species – human created concept to categorize organisms.
j. biological species concept – group of actually/potentially interbreeding individuals that
ae reproductively isolated.
i. Issues:
1. Only applies to sexually reproducing species. → doesn’t consider
asexual species.
2. Suggests hat 2 diff species would never made @ produce offspring’s →
what about successful hybrids?
3. Ecological species concept = species is a set of organisms adapted to a
particular set of resources, called a niche, in the environment → @
extremes of distribution “species” differ
4. Phylogenetic species concept – evolutionary history → some
populations are more unique than the rest.
k. speciation – the formation of new & distinct species in the course of evolution. →
reproductively isolated!
l. adaptive radiation - diversification of a group of organisms into forms filling different
ecological niches.
m. hybridization - Individual formed by mating between unlike forms, usually genetically
differentiated populations, or species.
EXPECTED OUTCOMES:
A) Understand the following B) Be able to define the C) Describe:
concepts: following terms: a. the importance of
a. gradualism a. fossil islands to the theory of
b. uniformitarianism b. microevolution evolution
c. bias in the fossil record c. macroevolution b. species isolating
d. continental drift d. reproductive mechanisms (pre &
e. descent with modification isolation postzygotic)
f. convergent evolution e. hybrid c. process of allopatric
g. natural selection f. sympatry speciation vs sympatric
h. relative fitness g. Selection types speciation
i. species (directional, d. the relationship
j. biological species concept stabilizing, and between natural
k. speciation disruptive) selection and different
l. adaptive radiation h. abiogenesis outcomes for hybrids in
m. hybridization i. protocells hybrid zones
n. reinforcement e. the scientific hypothesis
o. punctuated equilibrium. for how life on Earth first
p. Abiogenesis formed (4 steps)
A) Concepts:
a. Gradualism – evolution/speciation is a slow process by natural selectin that happens
over many generations.
b. Uniformitarianism - geologic processes have not changed throughout Earth's history.
“The present is the key to the past”
c. bias in the fossil record - refers to that not all life that has existed has fossilized, or if it
did fossilize, has been found. Therefore, there are gaps in the record.
d. continental drift – landmasses drift around on plates on hot mantle, and the relative
locations of landmasses have changed over time.
i. Consequences:
, 1. Change to the environment & climate = opportunities for diversification.
→ allopatric speciation
2. Mass extinctions
e. descent with modification - passing on of traits from parent organisms to their
offspring. Evolution!!
f. convergent evolution - Analogous traits are those that appear to be similar characters
but have not occurred as a result of common ancestry, but rather evolutionary
adaptations to similar environments.
g. natural selection - gives rise to adaptations. Selection of some individuals w/ certain
allele/characteristics over others because they’re better fit for survival & reproduction.
h. relative fitness – the ability for species w/ certain genes/characteristics to survive and
reproduce in an environment better than others.
i. species – human created concept to categorize organisms.
j. biological species concept – group of actually/potentially interbreeding individuals that
ae reproductively isolated.
i. Issues:
1. Only applies to sexually reproducing species. → doesn’t consider
asexual species.
2. Suggests hat 2 diff species would never made @ produce offspring’s →
what about successful hybrids?
3. Ecological species concept = species is a set of organisms adapted to a
particular set of resources, called a niche, in the environment → @
extremes of distribution “species” differ
4. Phylogenetic species concept – evolutionary history → some
populations are more unique than the rest.
k. speciation – the formation of new & distinct species in the course of evolution. →
reproductively isolated!
l. adaptive radiation - diversification of a group of organisms into forms filling different
ecological niches.
m. hybridization - Individual formed by mating between unlike forms, usually genetically
differentiated populations, or species.
