AP Biology Chapter 22 Flashcards

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Questions and Answers

Define evolution broadly and then give a narrower definition.

Evolution: Descent with modification; the idea that living species are descendants of ancestral species that were different from the present-day ones. It is also defined more narrowly as the change in the genetic composition of a population from generation to generation.

What did Aristotle believe about species and how could they be arranged?

Aristotle viewed species as fixed and recognized 'affinities' among organisms, concluding that life-forms could be arranged on a ladder of increasing complexity called the scala naturae.

What does the Old Testament hold regarding species?

The Old Testament holds that species were individually designed by God and therefore perfect.

What classification system did Carolus Linnaeus adopt?

Linnaeus adopted a nested classification system, grouping similar species into increasingly general categories. Signup and view all the answers

Explain the role of fossils in rock strata as a window to life in earlier times.

Fossils in sedimentary rocks provide a glimpse of past organisms, with new layers covering older layers, creating strata that document biological history. Signup and view all the answers

How would Georges Cuvier have explained the appearance of the record of life shown in the rock strata?

Cuvier opposed evolution and advocated for catastrophism, suggesting that boundaries between strata represented sudden catastrophic events. Signup and view all the answers

What ideas did James Hutton contribute to the understanding of Earth's geology?

Hutton proposed that Earth's geologic features could be explained by gradual mechanisms still operating today. Signup and view all the answers

What is the principle of uniformitarianism proposed by Charles Lyell?

Lyell’s principle of uniformitarianism states that geologic processes are constant over time and operate similarly in the past as they do today. Signup and view all the answers

What is the importance of the principle of uniformitarianism?

It suggests that Earth must be much older than the widely accepted age of a few thousand years because geologic change results from slow, continuous actions. Signup and view all the answers

What are the two principles of Lamarck's mechanism of evolution?

<ol> <li>Use and disuse: body parts that are used become larger and stronger, while those not used deteriorate. 2) Inheritance of acquired characteristics: modifications of use and disuse can be passed to offspring.</li> </ol> Signup and view all the answers

What is considered the great importance of Lamarck's ideas?

Lamarck recognized that the match of organisms to their environments could be explained by gradual evolutionary change rather than special creation. Signup and view all the answers

What are adaptations, and can you give two examples?

Adaptations are inherited characteristics that enhance survival and reproduction. Examples include the mottled coloration of a fawn and the sharp talons of birds of prey. Signup and view all the answers

Explain the process of natural selection.

Natural selection is a process where individuals with certain inherited traits tend to survive and reproduce at higher rates than others, leading to evolution. Signup and view all the answers

Summarize Darwin's observations that drive changes in species over time.

<ol> <li>Variations in traits exist. 2) These variations are heritable. 3) Species overproduce. 4) There is competition for resources.</li> </ol> Signup and view all the answers

From Darwin's observations, what two inferences did he make?

<ol> <li>Individuals with traits that increase survival and reproduction leave more offspring. 2) Unequal survival and reproduction leads to the accumulation of favorable traits over generations.</li> </ol> Signup and view all the answers

What can differential reproductive success lead to over time?

It can lead to an increase in the frequency of individuals with favorable adaptations and refine the match between organisms and their environment, potentially giving rise to new species. Signup and view all the answers

Explain the reasoning behind the phrase 'survival of the fittest'.

Individuals do not evolve; populations evolve. Signup and view all the answers

What is MRSA?

MRSA is methicillin-resistant Staphylococcus aureus, a flesh-eating strain of bacterium. Signup and view all the answers

How does research on soapberry bugs demonstrate observable evolutionary change?

Researchers studied beak length evolution in soapberry bug populations feeding on introduced plants with larger fruit, showing natural selection led to longer beak lengths. Signup and view all the answers

How did MRSA become so dangerous?

MRSA became dangerous as S.aureus populations developed resistance to antibiotics like methicillin due to selective pressures during medical treatments. Signup and view all the answers

Do antibiotics cause bacteria to become resistant?

False Signup and view all the answers

List four evidences for evolution.

<ol> <li>Direct observation of evolution, 2) Homology, 3) Fossil record, 4) Biogeography.</li> </ol> Signup and view all the answers

How does the fossil record give evidence for evolution?

The fossil record documents evolution patterns, showing differences between past and present organisms and indicating extinctions. Signup and view all the answers

What are homologous structures?

Structures in different species that are similar due to common ancestry, such as mammalian forelimbs. Signup and view all the answers

What are vestigial structures?

Features in an organism that are historical remnants of structures that served functions in ancestors, like pelvic bones in snakes. Signup and view all the answers

What are analogous structures?

Structures that are similar due to convergent evolution and not because of common ancestry, like the wings of bats and butterflies. Signup and view all the answers

How do homologous structures give evidence for evolution?

They represent variations on a structural theme present in common ancestors. Signup and view all the answers

What is summarized in an evolutionary tree?

An evolutionary tree reflects evolutionary relationships among groups of organisms. Signup and view all the answers

Explain convergent evolution and how analogous structures can arise.

Convergent evolution is the independent evolution of similar features in different lineages, resulting in analogous structures that share functions, not ancestry. Signup and view all the answers

Can you give two examples of convergent evolution?

Examples include the sugar glider and the flying squirrel, and the evolution of wings in birds and bats. Signup and view all the answers

What is biogeography?

Biogeography is the geographic distribution of species, affected by factors like continental drift and the presence of endemic species. Signup and view all the answers

Study Notes

Evolution Overview

Evolution is defined as descent with modification; living species are descendants of different ancestral species.
A narrower definition focuses on the genetic changes within a population across generations.

Historical Perspectives on Species

Aristotle viewed species as fixed and created a scala naturae, a hierarchical classification reflecting increasing complexity.
The Old Testament describes species as individually designed and perfect creations by God.
Carolus Linnaeus established a nested classification system but attributed species similarities to divine creation rather than evolutionary links.

Fossils and Geological Evidence

Fossils are often found in sedimentary rocks, providing evidence of past life forms and how they correlated with Earth's layers (strata).
Georges Cuvier proposed catastrophism, suggesting that species extinctions were caused by sudden, drastic events rather than gradual evolution.
James Hutton introduced the idea that geological features are the result of gradual processes, influencing Darwin's thoughts on evolution.
Charles Lyell's principle of uniformitarianism posits that these gradual geological processes occur at a constant rate over time, implying an Earth much older than previously thought.

Early Theories of Evolution

Jean-Baptiste de Lamarck proposed the mechanisms of use and disuse, suggesting that body parts used frequently develop stronger, while unused ones deteriorate.
He also introduced the concept of inheritance of acquired characteristics, suggesting modifications can be passed to offspring.
Lamarck's emphasis on gradual adaptation over special creation laid groundwork for future evolutionary theories.

Natural Selection and Adaptations

Charles Darwin identified natural selection as the primary mechanism for evolution, driven by adaptations—traits that enhance survival and reproduction.
Examples of adaptations include a fawn's coloration for camouflage and specialized features of birds of prey for hunting.
Natural selection operates as individuals with favorable traits are more likely to survive and reproduce, leading to changes in populations over generations.

Observations Driving Evolutionary Change

Key observations by Darwin include the existence of trait variation, heritability of traits, species overproduction, and competition for resources.
Inferences from these observations suggest that advantageous traits accumulate in populations over time, leading to evolutionary change.

Differential Reproductive Success

Differential reproductive success enhances the prevalence of beneficial adaptations, which can lead to the formation of new species.
The phrase "survival of the fittest" highlights that populations, rather than individuals, undergo evolutionary change over time.

Modern Examples and Evidence of Evolution

MRSA (methicillin-resistant Staphylococcus aureus) illustrates evolution through antibiotic resistance developed over time from selective pressures.
Research on soapberry bugs shows how beak length evolved in response to changes in food sources due to introduced plant species.

Evidence Supporting Evolution

Evolution can be directly observed, exemplified by antibiotic-resistant bacteria.
Homology demonstrates shared ancestry through structural similarities among different species, such as mammalian forelimbs.
The fossil record illustrates historical biodiversity and species extinction patterns.
Biogeography examines species distribution shaped by geological and environmental factors.

Structural Evidence for Evolution

Homologous structures share a common ancestor, showing structural similarities despite differing functions.
Vestigial structures, remnants from ancestors, illustrate evolutionary change, such as leg bones in some snake species.
Analogous structures arise from convergent evolution, where unrelated species develop similar features to solve similar environmental challenges.

Convergent Evolution

Convergent evolution results in species developing similar traits independently due to adapting to analogous environments, like sugar gliders and flying squirrels, or the wings of bats and birds.
Biogeography studies how geographic distribution and historical movements, like continental drift, impact species distribution and the presence of endemic species unique to specific regions.

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Description

Test your understanding of evolution with these flashcards from AP Biology Chapter 22. This chapter explores the concept of descent with modification and provides insights into how living species evolve over generations. Use these flashcards to reinforce key definitions and ideas essential to Darwinian evolution.