Biology Chapter Overview and Key Claims

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Questions and Answers

What is the role of selective pressure in evolution?

It enhances genetic diversity within a population

It influences survivability through biotic or abiotic factors (correct)

It ensures that all species reproduce at the same rate

It decreases the rate of natural selection

Which statement accurately reflects Darwin's evidence for gradual species change?

All species evolve simultaneously without any time delay

The pace of change is extremely slow, supporting gradual evolution (correct)

New species emerge instantaneously from existing ones

Species change rapidly due to environmental shifts

What does the concept of descent with modification imply?

Present day species have evolved from common ancestors (correct)

Species remain fixed and do not change over time

Evolution occurs randomly without a pattern

All species are identical to their ancestors

How is adaptation defined in an evolutionary context?

Traits that enhance survivability in an environment Signup and view all the answers

Which of the following supports the multiplication of species concept?

New species can originate from the splitting of existing species Signup and view all the answers

What does a cladogram represent in biology?

The evolutionary relationships amongst species Signup and view all the answers

Which of the following terms describes a group that includes a common ancestor and all its descendants?

Monophyletic Signup and view all the answers

Which of the following best describes the term 'outgroup' in phylogeny?

A different group outside the group of interest Signup and view all the answers

What is the purpose of the parsimony principle in constructing phylogenetic trees?

To provide the explanation with the least number of changes Signup and view all the answers

What is a phylogenetic tree primarily used for?

To show the evolutionary history and relationships among species Signup and view all the answers

What results from natural selection following extinction events?

Emergence of new evolutionary pathways Signup and view all the answers

Which grouping fails to include all descendants of a common ancestor?

Paraphyletic Signup and view all the answers

What characterizes structural similarities in species?

Similar metabolic pathways and skeletal structures Signup and view all the answers

What is an example of species change as provided in Darwin's claims?

Finches developed slightly different beak structures on different islands. Signup and view all the answers

Which factor is essential for natural selection to occur according to Darwin's evidence?

Competition for limited resources. Signup and view all the answers

What does the term 'sexual dimorphism' refer to?

Differences in characteristics between males and females in the same species. Signup and view all the answers

Which evidence supports the idea of artificial selection?

Humans breeding carrier pigeons for desired traits. Signup and view all the answers

Which concept is necessary for the process of natural selection to impact the fitness of organisms?

Variation among organisms. Signup and view all the answers

What does Darwin's concept of fitness refer to?

The reproductive success of an organism. Signup and view all the answers

In the context of Darwin's evidence, what does the Grant and Grant study illustrate?

Actual examples of natural selection in modern organisms. Signup and view all the answers

How did Malthus influence Darwin's concept of natural selection?

By discussing competition for limited resources among organisms. Signup and view all the answers

What characterizes mass extinctions compared to normal extinction rates?

They involve a rapid increase in extinction rates during a specific period. Signup and view all the answers

Which statement accurately describes the Malthusian Theory in relation to population dynamics?

It suggests that competition for limited resources leads to species extinction. Signup and view all the answers

In which scenario is extinction more likely to occur?

During times of environmental stress or catastrophe. Signup and view all the answers

What is a primary factor that distinguishes artificial selection from natural selection?

Humans select favorable traits in species during artificial selection. Signup and view all the answers

Which statement about homologous structures is true?

They indicate a common ancestry among species. Signup and view all the answers

What role does genetic variation play in a species' ability to adapt?

It increases the likelihood of successful adaptations. Signup and view all the answers

Which of the following best defines the concept of 'fitness' in evolutionary terms?

The ability to survive and produce fertile offspring. Signup and view all the answers

What is the main concept of convergent evolution?

Unrelated species develop similar traits due to similar environmental challenges. Signup and view all the answers

What is a significant consequence of habitat loss on biodiversity?

It often leads to increased competition among species. Signup and view all the answers

What characteristic of a cladogram indicates shared ancestry?

Nodes represent species diverging from an ancestor. Signup and view all the answers

Which factor is not considered a selective pressure on a population?

Genetic mutations within individuals. Signup and view all the answers

What is the main result of mutations in the context of evolution?

They contribute to a new phenotype that can be subject to natural selection. Signup and view all the answers

Which of the following statements accurately describes the concept of speciation?

It involves reproductive isolation leading to the formation of new species. Signup and view all the answers

What does the term 'niche' refer to in an ecological context?

The role and position an organism occupies in its environment. Signup and view all the answers

Study Notes

Textbook Chapters

Chapter 22 (all Chapters)
23.4 (Not Heterozygous advantage)
25.2, 25.4, 25.6
26.1, 26.1 (excluding molecular homologies), 26.3, 26.6 (two domains to five domains section)

AP Classroom Videos

7.1
7.2
7.3
7.6
7.7
7.9
7.11

Claim One: Species Change (Original Claim)

Finches developed slightly different beak structures on different islands
Tortoises developed different shells
Iguanas were able to swim
Fossils of extinct giant sloths from mainland South America were observed
Similarities were seen in embryos of different organisms (observed by Darwin during his voyage)

Claim Two: Natural Selection as a Mechanism for Change

Finches survival
Malthus theory of competition(organisms struggle for limited resources: food,space, mates, nutrients, light)
Sexual selection- the process where one sex chooses mates based on traits
Sexual dimorphism- difference in characteristics between males and females in a species
Artificial selection- the process where humans influence evolution through breeding (e.g. pigeons, peacocks)

Claim Three: Species Change Gradually

Pace of change is extremely slow

Claim Four: Descent with Modification/Common Ancestor

All present-day species have changed from ancestors
Homologous structures (same bone structures) are seen across different species

Claim Five: Multiplication of Species

One species can split into two
Species numbers have increased throughout history

Modern Evidence (Not Needed for this Test)

DNA evidence- similar genetic code in all species and becoming more different over time; metabolic pathways
Cladograms and Venn diagrams illustrate the relationships among species

Cladograms/Phylogenetic Trees

Changed how organisms are grouped (taxonomy)
Binomial system (Carl Linnaeus)- defining species based on genus and species

Extinction Results

Extinction- disappearance of a species
Extinction occurs naturally and over time, and during mass extinctions, rates are much higher
Mass extinctions- wipe out large numbers of species
Mass extinctions are caused by catastrophic events: rising sea levels, climate change, solar flares, volcanoes, and human activity

Theories (Do Not Need to Know Names Other than Malthus and Lyell)

Malthusian Theory: populations can be limited by resources resulting in conflicts.
Cuvier- Catastrophism: history is characterized by major events
Hutton/Lyell- Uniformitarianism/Gradualism: changes occur slowly over time

Definitions (Class and AP Classroom)

Evolution- change in the proportion of a species over generations due to the environment
Evidence for evolution- fossil evidence, geological evidence, geographical evidence, physical evidence, biochemical evidence
Natural selection- process where organisms with traits better suited to their environment are more likely to survive and reproduce
Variation (within species)- differences between the organisms
Mutations
Reproduction - and conditions
Environmental conditions
Artificial selection- the selective breeding of traits by humans
Sexual selection- the selection mates based on traits
Sexual dimorphism- differing characteristics between sexes
Binomial system- defining species by their genus and species

Phylogeny

Evolutionary tree- diagram showing the evolutionary relationships among species
Tips- groups of descendants
Nodes- common ancestors
Outgroup- different group outside of the group of interest
Root- common ancestor of all species on the cladogram
Cladogram- diagram to show relationships
Clade- group sharing a common ancestor
Parsimony - simplest explanation.
Monophyletic- group with a common ancestor and all descendants
Polyphyletic- missing a common ancestor
Paraphyletic- missing some descendants

Convergent Evolution

Process where similar environmental conditions select for similar features in different species

Analogous Structures

Structures that evolved independently in different species due to similar environmental pressures

Analogous Structure

Structures that evolved independently in different species due to similar environmental conditions and selective pressures

Mass Extinction

Extinction rates over a certain period that exceed the background extinction rate, a naturally occurring process.
Speciation - process where organisms become reproductively isolated that form new species.
Niche- the role an organism occupies in a specific habitat.

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Description

This quiz covers key concepts from various chapters in biology, including species change and natural selection mechanisms as discussed in Darwin's theories. Understanding the adaptations of species such as finches and tortoises is crucial. Test your knowledge of the chapters and AP classroom videos related to these topics.