Evolutionary Biology Quiz

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Questions and Answers

What is the significance of homologous structures in the study of evolution?

They highlight how natural selection modified body parts from a common ancestor for various functions. (correct)

They indicate that all species have identical body structures.

They show how different species independently evolved similar traits.

They provide no evidence of evolutionary relationships between organisms.

Which of the following best describes vestigial organs?

Organs that are duplicated from another part of the body.

Highly functional organs necessary for survival.

Organs that have lost their original function but may still have minor uses. (correct)

Organs that have completely disappeared in modern organisms.

What does comparative embryology reveal about different organisms?

It provides evidence that different species can have similar developmental stages. (correct)

It indicates that organisms no longer share any common ancestry.

It shows that all organisms develop in exactly the same way.

It demonstrates that embryonic development is unaffected by environmental factors.

Why might the study of vestigial structures be important in understanding evolution?

They showcase organs that once had important functions and support the concept of evolution. Signup and view all the answers

What is a possible consequence of a neck pouch failing to form into the eustachian tube in humans?

It allows a direct connection from the mouth to the neck. Signup and view all the answers

What modern example demonstrates evolution by natural selection?

Staphylococcus aureus infections Signup and view all the answers

Which was a commonly held belief about species during the 19th century?

Each species was created individually Signup and view all the answers

What is one of the primary pieces of evidence for evolution based on molecular data?

Similar genetic codes across all organisms Signup and view all the answers

What does divergent evolution refer to?

The splitting of a population into two isolated groups Signup and view all the answers

What idea did Charles Baptiste Lamarck contribute to the understanding of evolution?

Acquired characteristics can be inherited Signup and view all the answers

What aspect of Lamarck's theory was considered correct?

Change occurs in species over time Signup and view all the answers

Which mechanism is described as the evolution occurring in a single ancestral group to adapt to different environments?

Adaptive radiation Signup and view all the answers

Which aspect is NOT typically associated with evidence from biogeography?

Similar DNA sequences across species Signup and view all the answers

What mechanism did Lamarck incorrectly associate with evolution?

Inheritance of acquired characteristics Signup and view all the answers

What is a key characteristic of organisms that develop resistance to antibiotics?

They exhibit evolution by natural selection Signup and view all the answers

How do researchers utilize DNA sequences in studying evolutionary relationships?

By comparing DNA base pair sequences and amino acids Signup and view all the answers

What is an example of convergent evolution?

Whales and fish developing streamlined bodies Signup and view all the answers

Which statement about Lamarck's theories is accurate?

He provided insight into change over time Signup and view all the answers

How did beliefs about species' origins change by the end of the 19th century?

Species were thought to change over time Signup and view all the answers

Which term describes the gradual change of species over a long period?

Gradual evolution Signup and view all the answers

What drives the adaptive changes in a species according to the mechanisms of evolution?

The need to adapt to different environments Signup and view all the answers

What characterizes the tempo of evolution?

The speed at which organisms diverge and adapt Signup and view all the answers

What best describes the concept of phyletic gradualism?

All lines change at approximately the same rate over time. Signup and view all the answers

Which statement accurately characterizes the process of genetic variation through mutations?

Mutations can be harmful, helpful, or neutral. Signup and view all the answers

In the context of gene duplication, what role does the mutated copy usually play?

It can develop a new function that differs from the original. Signup and view all the answers

Which of the following best explains genetic recombination?

It does not change the frequency of alleles in a gene pool. Signup and view all the answers

How does punctuated equilibrium differ from phyletic gradualism?

It suggests that structural changes occur in fits and starts. Signup and view all the answers

What could be a dangerous scenario for species like the Cheetah due to its low genetic variation?

Reduced adaptability to environmental changes Signup and view all the answers

Which of the following is NOT a condition for the Hardy-Weinberg Principle to hold true?

High migration rates Signup and view all the answers

How does genetic drift primarily affect a population?

It causes random changes over generations. Signup and view all the answers

What is the role of mutations in evolution?

To provide new alleles for natural selection. Signup and view all the answers

Which statement best describes Hardy-Weinberg Equilibrium?

Stable allele and genotype frequencies in absence of external pressures. Signup and view all the answers

What does gene flow in a population involve?

The introduction of new alleles through migration. Signup and view all the answers

Which of the following is a consequence of a small population size regarding genetic drift?

Greater sensitivity to random events. Signup and view all the answers

What happens to allele frequencies in the absence of outside influences according to the Hardy-Weinberg Principle?

They will remain constant. Signup and view all the answers

Which factor does NOT contribute to genetic variation in a population?

Environmental changes Signup and view all the answers

Why is the Hardy-Weinberg Principle important in studying populations?

It provides a standard to compare against real populations. Signup and view all the answers

What is the primary outcome of directional selection?

Extreme phenotypes are favored. Signup and view all the answers

Which type of selection favors intermediate forms while eliminating extremes?

Stabilizing selection Signup and view all the answers

Disruptive selection favors which of the following phenotypes?

Extreme forms at both ends Signup and view all the answers

What is a characteristic of allopatric speciation?

Populations are geographically isolated. Signup and view all the answers

Which reproductive isolating mechanism could prevent a species’ sperm from fertilizing another species’ eggs?

Gametic isolation Signup and view all the answers

What defines sympatric speciation?

New species develop within the same habitat. Signup and view all the answers

What is the result of stabilizing selection on a population’s phenotypes?

Reduction of extremes, favoring the average. Signup and view all the answers

Which selection process would likely lead to a bimodal distribution of phenotypes in a population?

Disruptive selection Signup and view all the answers

What does geographic isolation in allopatric speciation result in?

Unique adaptations developing in each population. Signup and view all the answers

What phenomenon is likely to occur when extreme forms of a trait are less successful in a population?

Stabilizing selection is happening. Signup and view all the answers

What is the implication of reproductive isolating mechanisms in speciation?

They prevent interbreeding and promote the formation of new species. Signup and view all the answers

Which of the following is an example of a reproductive isolating mechanism related to mating behavior?

Behavioral isolation Signup and view all the answers

What factor is primarily responsible for the success of certain phenotypes during natural selection?

Environmental pressures favoring specific traits Signup and view all the answers

How does disruptive selection affect the genetic diversity of populations?

It leads to increased diversity by favoring extremes. Signup and view all the answers

Study Notes

Mechanisms of Evolution

Evolution is the change in the heritable characteristics of biological populations over successive generations.
Resistance to antibiotics in Staphylococcus aureus bacteria is a modern example of evolution by natural selection.

Emergence of Evolution as a Concept

Nineteenth-century belief held that species were created individually and did not change over time.
Charles Darwin and Alfred Russel Wallace proposed that all species descended with modification from a common ancestor.
Natural selection is the process by which species adapt to their environment increasing their chance of survival and reproduction.

Evidence for Evolution

Fossil records, geologic records, comparative morphology, and comparative biochemistry provide evidence of evolution.
Fossil records consist of organisms with different shapes and sizes from past geological times. Fossils are found in sedimentary rock which forms in layers.
Fossils in neighboring layers are similar, with older rocks containing simpler forms. This illustrates the progression of life over geological time.
Paleontologists have discovered intermediate forms between major groups of an organism, such as Archaeopteryx (a transitional form between dinosaurs and birds).
Evidence from comparative anatomy demonstrates homologous structures (similar organs in different organisms) supporting the idea of descent with modification.
Vestigial organs (leftover organs with no apparent use, e.g., appendix and wisdom teeth in humans) are also evidence of evolutionary history.
Comparative embryology reveals similarities in embryonic stages across different organisms, suggesting a common ancestor.
Evidence from molecules indicates that all life evolved from a common ancestor and that all living organisms share basic molecules (e.g., similar DNA bases and amino acids).
Biogeography (the geographic distribution of organisms) provides evidence of evolution. Similar large birds found on different southern continents suggest descent with modification.

Pathways of Descent

Gradual change over long periods of time demonstrates how species evolve.
Divergent evolution is the splitting of population into reproductively isolated populations.
Adaptive radiation occurs when a single ancestral group evolves into a variety of species adapted to different environments.
Convergent evolution shows how unrelated species develop similar characteristics in response to similar environmental pressures.
Tempo of evolution describes the rate at which species converge, diverge, or radiate into new ones, either by gradual change or punctuated equilibrium (sudden bursts of change).

Genetic Variation

Single-gene mutations and gene duplication are important sources of new genetic variation.
Genetic recombination shuffles existing alleles, maintaining genetic diversity in a population's gene pool.
Populations with low genetic variation, like cheetahs, are vulnerable to threats like disease.

How Genetic Variation Is Inherited

The Hardy-Weinberg principle describes conditions under which allele and genotype frequencies in a population remain constant (no evolution). These conditions include no mutation, no migration, large population size, random mating, and no natural selection.

Agents of Evolution

Mutations change alleles into new forms.
Gene flow is the physical movement of alleles into a population via migration (e.g., antibiotic-resistant bacteria).
Genetic drift, occurring in small populations, alters allele frequencies randomly over generations (bottleneck and founder effects).
Bottleneck effect is the reduction of a population size due to a disaster leading to pronounced genetic drift.
Founder effect is the low genetic variation seen in populations established by a small number of individuals.
Non-random mating (e.g., inbreeding) increases homozygosity, potentially lowering fitness when deleterious recessive alleles are expressed.

Natural Selection Revisited

Natural selection alters the course of evolution through directional selection (favoring extreme forms), stabilizing selection (favoring intermediate forms), and disruptive selection (favoring forms at both ends of the range).

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Description

Test your knowledge on the key concepts of evolutionary biology, including homologous structures, vestigial organs, and the theories proposed by Lamarck and Darwin. This quiz covers essential principles that demonstrate how evolution shapes the diversity of life on Earth.