Evidence and Mechanisms of Evolution

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Questions and Answers

Which type of immunity is characterized by a specific, slower response involving memory?

Innate immunity

Nonspecific immunity

Immediate immunity

Adaptive immunity (correct)

Dendritic cells are responsible for engulfing pathogens.

False

What is the purpose of negative feedback loops in homeostasis?

To reverse deviations from set points.

The electrical signal triggered when a neuron depolarizes is called an ______.

action potential Signup and view all the answers

Match the following ecological terms with their correct definitions:

Population size = Total number of individuals Species density = Number of individuals per unit area Exponential growth = Rapid growth without limits Logistic growth = Growth with carrying capacity limits Signup and view all the answers

Which of the following is an example of density-dependent factors?

Disease Signup and view all the answers

Antibodies are produced by T cells to fight off antigens.

False Signup and view all the answers

What type of species distribution pattern is characterized by individuals grouped in patches?

Clumped distribution Signup and view all the answers

What type of selection favors the extreme phenotypes at both ends of a trait spectrum?

Disruptive Selection Signup and view all the answers

Homologous structures indicate different evolutionary origins.

False Signup and view all the answers

What is the main difference between allopatric and sympatric speciation?

Allopatric speciation involves geographic barriers, while sympatric speciation occurs without such barriers. Signup and view all the answers

The process by which traits improving survival and reproduction increase in frequency is called __________.

natural selection Signup and view all the answers

Match the following speciation types with their descriptions:

Allopatric Speciation = Geographic barriers separate populations Sympatric Speciation = Reproductive barriers arise without physical separation Bottleneck Effect = Drastic population reduction reduces genetic diversity Founder Effect = A few individuals establish a new population Signup and view all the answers

Which type of evidence for evolution involves comparing the early developmental stages of different species?

Embryology Signup and view all the answers

Genetic drift has a more significant effect on large populations compared to small populations.

False Signup and view all the answers

Name two types of barriers in reproductive isolation.

Prezygotic barriers and postzygotic barriers. Signup and view all the answers

Study Notes

Evidence for Evolution

Fossil Evidence: Shows transitions between species over time. Archaeopteryx is an example, linking dinosaurs to birds.
Anatomy: Homologous structures share ancestry (e.g., mammalian limbs); analogous structures result from convergent evolution.
Embryology: Similar early development in different species suggests common ancestry.
Biogeography: Geographic distributions reflect evolutionary history, like Darwin's finches.
Molecular Biology: DNA and protein similarities show evolutionary relationships. Humans and chimpanzees, for instance, share significant genomic similarities.

Mechanisms of Evolution

Natural Selection: Traits boosting survival/reproduction increase frequency. Peppered moths are an example.
Mutation: Random DNA changes introduce new traits, like antibiotic resistance in bacteria.
Genetic Drift: Random changes in allele frequencies, especially in small populations. The bottleneck effect is a drastic reduction in population size (cheetahs). The founder effect establishes a new population with a small subset of individuals (island birds).
Gene Flow: Movement of alleles between populations (e.g., migration).

Types of Selection

Natural Selection: Traits enhancing fitness triumph (camouflage in prey).
Artificial Selection: Human-driven selection (dog breeding).
Sexual Selection: Traits improving mating success (peacock feathers).

Species Concepts

Biological Species Concept: Groups of interbreeding populations that produce fertile offspring. Limitations include inability to classify asexual species or fossils.
Morphological Species Concept: Classifies species based on physical traits.

Speciation

Allopatric Speciation: Geographic barriers separate populations (e.g., river divides squirrel populations).
Sympatric Speciation: Reproductive barriers within the same area (e.g., polyploidy in plants).

Reproductive Barriers

Prezygotic Barriers: Prevent fertilization (e.g., temporal isolation in frogs).
Postzygotic Barriers: Hybrid offspring are inviable or infertile (e.g., mules).

Modes of Selection

Directional Selection: Favors one extreme (e.g., antibiotic resistance).
Stabilizing Selection: Favors intermediate traits (e.g., human birth weight).
Disruptive Selection: Favors extremes (e.g., varied terrain leading to different colored mice).

Body's Systems (Chapter 16)

Four Tissue Types:
- Epithelial: Covers surfaces, like skin.
- Connective: Supports and connects, like bone and blood.
- Muscle: Facilitates movement (e.g., skeletal muscle).
- Nervous: Processes and transmits information (e.g., neurons).
Homeostasis: Maintaining internal balance (e.g., body temperature and blood sugar).
Negative Feedback Loops: Reverse deviations from set points (e.g., sweating when overheated).
Action Potential: Electrical signal in neurons, transmitting information along axons.

Immune System (Chapter 17)

Innate vs. Adaptive Immunity:
- Innate: Immediate, non-specific (e.g., skin, phagocytes).
- Adaptive: Slower, specific, with memory (e.g., antibodies).
Immune Cells:
- Phagocytic cells: Engulf pathogens (e.g., macrophages).
- T cells: Attack infected cells or aid other responses.
- B cells: Produce antibodies.
- Dendritic cells: Present antigens to T cells.
Antigens and Antibodies: Antigens trigger immune responses; antibodies are proteins neutralizing antigens.

Population and Community Ecology (Chapter 19)

Population Size vs. Density: Size is total individuals; Density is individuals per area.
Species Distribution Patterns:
- Random: No pattern (e.g., dandelions).
- Clumped: Grouped in patches (e.g., herds).
- Uniform: Evenly spaced (e.g., penguins).
Population Growth:
- Exponential: Rapid growth, no limits (J-curve).
- Logistic: Growth with carrying capacity limits (S-curve).
Density-Dependent vs. Density-Independent Factors:
- Density-dependent: Impact depends on population size (e.g., disease).
- Density-independent: Affects population regardless of size (e.g., natural disasters).
Interspecific Interactions:
- Competition: Resources competed for (lions and hyenas).
- Predation: Predator-prey interactions (hawk and mouse).
- Herbivory: Herbivores consuming plants (deer eating leaves).
- Commensalism: One benefits; other unaffected (barnacles on whales).
- Mutualism: Both benefit (bees and flowers).
- Parasitism: One benefits; other harmed (ticks on dogs).
Defenses Against Predation and Herbivory: Plants (thorns, toxins); Animals (camouflage, mimicry, physical defenses like porcupine quills).

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Description

Explore the foundational concepts of evolution through various types of evidence and mechanisms. This quiz covers fossil records, anatomical structures, embryological similarities, biogeography, and molecular biology as proof of evolution. Delve into the processes that drive evolutionary change, including natural selection, mutation, and genetic drift.