©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
Biology Evolution Exam 1 Study Guide
Solutions
Evolution - ANSWER✔✔1. theory that all organisms are related by common ancestry and due to descent
with modification, changed over time
2. change in genotype/genetic make-up of a population from one generation to the next
What must happen for evolution to occur by natural selection - ANSWER✔✔1. individuals must vary/be
different
2. traits must be heritable
3. differential of survival: survival and reproductive success must vary and it's not by chance
Adaptive Evolution - ANSWER✔✔individual with highest fitness will survive and reproduce. ability to
pass on genes to its offsprings
How do certain phenotypes become dominant over others in a population, leave population, and
emerge - ANSWER✔✔nature favors traits that lead to high fitness, becoming more common in a
population: Adaptive evolution
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, ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
-disadvantageous traits dont survive so cant pass on traits --> leaves population
-new traits arise because of mutations (mostly deleterious or neutral) but if good, then remain in
population
What leads to natural selection - ANSWER✔✔Descent with modification:
Both parents pass down traits but the traits have slight modifications. because of this, evolution changes
a population over time: there are the phenotypes from the ancestors and the new traits that have
developed from advantageous mutations.
Evidence for evolution/descent with modification - ANSWER✔✔1. Biogeography
2.Homology
3. Molecular Structure
4. Vestigial Traits
Biogeography - ANSWER✔✔shows how organisms differ over geographic space
ex. Birds on Galapagos islands: all look physically similar, but vary somewhat to fit niche. Shows that
came from common ancestor but changed over time
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, ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
Homology - ANSWER✔✔similar structures or genes because of common ancestor but acquired
differences through evolution
ex. bats, humans, and dogs have same bone structure but used for diff. functions
ex. embryo of chicken, snake, human, and cat look alike during first stage
Molecular Structure - ANSWER✔✔all organisms have same genetic code (because of common ancestor)
with little difference.
-->differences exist due to mutations that are not deleterious and therefore still allow the organism to
function normally.
ex. DNA of mouse and human. Evolution proved because of some change in gene sequence even though
majority are parallel.
Vestigial Traits - ANSWER✔✔phenotypes found in both modern organism and ancestor, but serves no
purpose for modern organism. Natural selection does not act to eliminate it because not harmful to
organism. Evidence for evolution because significant for ancestor, but due to change over time, serves no
function to us
Page 3/17
FIRST PUBLISH OCTOBER 2024
Biology Evolution Exam 1 Study Guide
Solutions
Evolution - ANSWER✔✔1. theory that all organisms are related by common ancestry and due to descent
with modification, changed over time
2. change in genotype/genetic make-up of a population from one generation to the next
What must happen for evolution to occur by natural selection - ANSWER✔✔1. individuals must vary/be
different
2. traits must be heritable
3. differential of survival: survival and reproductive success must vary and it's not by chance
Adaptive Evolution - ANSWER✔✔individual with highest fitness will survive and reproduce. ability to
pass on genes to its offsprings
How do certain phenotypes become dominant over others in a population, leave population, and
emerge - ANSWER✔✔nature favors traits that lead to high fitness, becoming more common in a
population: Adaptive evolution
Page 1/17
, ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
-disadvantageous traits dont survive so cant pass on traits --> leaves population
-new traits arise because of mutations (mostly deleterious or neutral) but if good, then remain in
population
What leads to natural selection - ANSWER✔✔Descent with modification:
Both parents pass down traits but the traits have slight modifications. because of this, evolution changes
a population over time: there are the phenotypes from the ancestors and the new traits that have
developed from advantageous mutations.
Evidence for evolution/descent with modification - ANSWER✔✔1. Biogeography
2.Homology
3. Molecular Structure
4. Vestigial Traits
Biogeography - ANSWER✔✔shows how organisms differ over geographic space
ex. Birds on Galapagos islands: all look physically similar, but vary somewhat to fit niche. Shows that
came from common ancestor but changed over time
Page 2/17
, ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
Homology - ANSWER✔✔similar structures or genes because of common ancestor but acquired
differences through evolution
ex. bats, humans, and dogs have same bone structure but used for diff. functions
ex. embryo of chicken, snake, human, and cat look alike during first stage
Molecular Structure - ANSWER✔✔all organisms have same genetic code (because of common ancestor)
with little difference.
-->differences exist due to mutations that are not deleterious and therefore still allow the organism to
function normally.
ex. DNA of mouse and human. Evolution proved because of some change in gene sequence even though
majority are parallel.
Vestigial Traits - ANSWER✔✔phenotypes found in both modern organism and ancestor, but serves no
purpose for modern organism. Natural selection does not act to eliminate it because not harmful to
organism. Evidence for evolution because significant for ancestor, but due to change over time, serves no
function to us
Page 3/17
