Introductory Biology Unit 4: Evolution & Natural Selection; Speciation; Taxonomy & Biodiversity

How does the scientific meaning of "theory" differ from the common, everyday meaning of the word?

A scientific theory is a proposed explanation for a wide range of observations supported by a wide range of evidence. A theory in everyday language is a guess.

Explain the evidence and reasonings that supports the following statement: The amount of time since light-sensitive molecules evolved in very early animal ancestors is more than 1000 times greater than the amount of time needed to evolve a roughly spherical eye with a lens for animals that have one generation per year.

Ample time for evolution of eye with roughly spherical lens

Octopus eyes and human eyes have a similar shape and a lens to focus light. Are these similarities due to homology or analogy? Explain your reasoning

Analogy; involved independently in mollusks and chordates

Microevolution, or evolution at its smallest scale, occurs when... a. An individual's traits change in response to environmental factors b. A community of organism changes due to the extinction of several dominant species c. A new species arises from an existing species d. A population's allele frequencies change over a span of generations

D. A population's allele frequencies over a span of generations

Which of the following situations will lead to natural selection? a. The seeds of two plants land near each other and one grows larger than the other b. Two types of fish east the same kind of food, and one is better able to gather food than the other c. Male lions compete for the right to mate with females, with only one possible winner d. All of the above

D. all of the above

The lens in an octopus eye also focuses light to produce images that provide detailed visual information. Explain why the ability to form images would be more useful for an octopus than for a limpet.

Forming images would allow octopus to recognize prey

Do you think genetic drift would happen more quickly on an island or on the mainland?

Genetic drift is likely to occur more rapidly on an island, where smaller populations are expected to occur.

Octopus and human eyes have similar light-sensitive molecules that contain opsin proteins. Is the similarity due to homology or analogy? Explain you reasoning.

Homlogy; shared in common ancestors & early eukaryotes

How does genetic drift differ from natural selection? Provide examples of each in your response

In genetic drift, it is a random change in allele frequencies Examples: Allele X occurs at 10% frequency; when hunters kill large population of a specific animal causing the population to be homozygous in every gene Natural selection: The process by which adaptive traits become more common in a population Examples: When a certain animal is eaten by two separate animals; humans who develop a tolerance for lactose in milk

Do antibiotics cause bacteria to become resistant? Explain your response

It is because of the overuse and misuse of an antibiotic that would cause resistance, it could also be cause by the pathogens that are naturally resistant, or because of mutations in chromosomal genes.

Two species of fish had recently undergone sympatric speciation. The males of each species had a different coloring through which females could identify and choose a partner from her own species. After some time, pollution made the lake so cloudy it was hard for females to distinguish colors. What might take place in this situation?

It is likely the two species would start to reproduce with each other. Depending on the viability of their offspring, they may fuse back into one species.

What is the difference between micro- and macroevolution? a. Microevolution describes the evolution of small organisms, such as insects, while macroevolution describes the evolution of large organisms, like people and elephants. b. Microevolution describes the evolution of microscopic entities, such as molecules and proteins, while macroevolution describes the evolution of whole organisms. c. Microevolution describes the evolution of populations, while macroevolution describes the emergence of new species over long periods of time. d. Microevolution describes the evolution of organisms over their lifetimes, while macroevolution describes the evolution of organisms over multiple generations.

Microevolution describes the evolution of organisms over their lifetimes, while macroevolution describes the evolution of organisms over multiple generations.

Define microevolution and macroevolution and give an example of each

Microevolution describes the evolutions of organisms over their lifetimes Example: Antibiotic resistance Macroevolution describes the evolution of organisms over multiple generations Example: Extinction of dinosaurs

How do genetic mutations contribute to evolution by natural selection?

Mutations are the original source of new alleles, but a change in the environment could favor one previously neutral or somewhat harmful. Beneficial mutations, through natural selection, tend to increase in frequency in a population over generations. It is also mutations that lead to staggering biodiversity among the Earth's population.

Use the example of recent trends in black vs. speckled forms of the peppered moth to illustrate the following generalization: Natural selection acts on individuals, but only populations evolve.

Natural selection favors black moths on darker branches/trunks and selects against spotted/speckled peppered moths. Overtime the allele frequency changes in the population (evolution).

Due to natural selection, heritable traits that contribute to increased fitness become more common in a population. To understand how natural selection could gradually improve the lens in octopus eyes, imagine an ancient population of octopuses with two alleles of a gene that influenced the formation of the lens. Suppose that most of the octopuses had the allele that resulted in a lens that produced fuzzy images, but a few of the octopuses had a new allele that resulted in a better lens that produced sharp clear images. Explain how this new allele could become more common in future generations of this population.

Octopuses with "new" allele would be better hunters, would have more energy for growth, survived, reproduction chance better "fitness"

Why do island chains provide ideal conditions for adaptive radiation to occur?

Organisms of one species can arrive to an island together and then disperse throughout the chain, each settling into different niches and exploiting different food resources to reduce competition.

Which animals belong to a clade that includes animals with hair? Which evolved first: hair or the amniotic egg?

Rabbits and humans belong in the clade that includes animals with hair. The amniotic egg evolved before hair because the Amniota clade is larger than the clade that encompasses animals with hair.

Explain the Hardy-Weinberg principle of equilibrium

States that if over generations the allele frequency in a population is constant, there is Hardy-Weinberg Equilibrium, however, there will be no evolution of the species.

Describe natural selection and give an example of natural selection at work in a population

The theory of natural selection stems from the observation that some individuals in a population survive longer and have more offspring than others: thus, more of their genes are passed to the next generation. For example, a big, powerful male gorilla is much more likely than a smaller, weaker one to become the population's silverback: the pack's leader who mates far more than the other males of the group. Therefore, the pack leader will father more offspring who share half of his genes and are likely to grow bigger and stronger like their father. Over time, the genes for bigger size will increase in frequency in the population, and the average body size, as a result, grows larger on average.

Why do scientists consider vestigial structures evidence for evolution?

Vestigial structures are considered evidence for evolution because most structures do not exist in an organism without serving some function either presently or in the past

A student wrote the following explanation of what caused the increase in the black form of the peppered moth after 1850 and then the decrease in the black form after 1950: When air pollution resulted in dark tree trunks and branches, the peppered moth needed to be dark so it would not be seen and eaten by birds. When air pollution was reduced so tree trunks and branches were lighter, the peppered moth needed to be lighter so it would not be eaten by birds. Write a specifically more accurate explanation of what happened to cause the trends in the proportion of black peppered moths.

When air pollution resulted in darker tree trunks and branches the black moths were less visible to predators. The black moth had increased "fitness" (they survived and reproduced). Spotted/speckled peppered moths were more likely to be eaten. (This would be renewed? when pollution declined & branches/ trunk were lighter).

Which situation would most likely lead to allopatric speculation? a. A flood causes the formation of a new lake b. A storm causes several large trees to fall down c. A mutation causes a new trait to develop d. An injury causes an organism to seek out an new food source

a. A flood causes the formation of a new lake

Which of the following best expresses the concept of natural selection? a. Differential reproductive success based on inherited characteristics b. Inheritance of acquired characteristics c. Change of acquired characteristics

a. Differential reproductive success based on inherited characteristics

A rabbit population consists of animals that are either very dark on top or very light on top. The color pattern is not related to sex. No rabbit shows intermediate coloration (medium darkness). This pattern might result from a. Disruptive selection b. Directional selection c. Stabilizing selection d. Sexual selection

a. Disruptive selection

Thirty people are selected for a long-term mission to colonize a planet many light-years away from Earth. The mission is successful, and the population rapidly grows to several hundred individuals. However, certain genetic diseases are unusually common in this group, and the group's gene pool is quite different from that of the Earth population they have left behind. Which of the following phenomena has left its mark on this population? a. Founder effect b. Bottleneck effect c. Natural selection

a. Founder Effect

Structures that evolved from the same structure in a common ancestor are a. Homologous b. Heterologous c. Analogous

a. Homologous

Population genetics is the study of__________ a. How allele frequencies in a population change over time b. Population of cells in an individual c. The rate of population growth d. How genes affect embryological development

a. How allele frequencies in a population change over time

Which of the following are assumptions of Hardy-Weinberg equilibrium? a. Large population b. Small population c. Nonrandom mating d. Random mating e. No mutations f. No gene flow

a. Large population; d. Random mating; e. No mutations and f. No gene flow

The ultimate source of all new alleles is a. Mutation b. Chromosomal duplication c. Genetic drift d. Natural selection

a. Mutation

In the three-domain system, the eukaryotes are represented a. Only with the domain Eukarya b. Only with the domain Archaea c. In all three domains

a. Only with domain eukaryote

During the __________ mass extinction, over 90% of marine species became extinct, possibly because of intense volcanic activity a. Permian b. Cretaceous c. Mesozoic

a. Permian

What kind of trait is important to cladistics? a. Shared derived traits b. Shared ancestral traits c. Analogous traits d. Parsimonious phylogenies

a. Shared derived traits

Human birth weight is a classic example of the result of: a. Stabilizing selection b. Disruptive selection c. Genetic drift

a. Stabilizing selection

Speciation without geographic isolation is called ____________ speciation a. Sympatric b. Allopatric c. Incomplete

a. Sympatric

Which of the following types of reproductive barriers separate a pair of species that could interbreed but for the fact that one mates at dusk and the other at dawn? a. Temporal isolation b. Habitat isolation c. Behavioral isolation d. Mechanical isolation

a. Temporal isolation

Structures that evolved from the same structure in a common ancestor are a. homologous b. analogous c. convergent adaptions

a. homologous

The origin of all genetic variation is: a. mutation b. asexual reproduction c. mitosis

a. mutation

In the three-domain system, the eukaryotes are represented a. only within the domain Eukarya b. only with the domain Archaea c. in all three domains

a. only within the domain Eukarya

During the _________ mass extinction, over 90% of marine species became extinct, possibly because of intense volcanic activity a. permian b. cretaceous c. mesozoic

a. permian

Evolutionary adaption: a. refers both to the process by which organisms become better matched to their environment and to the features of an organism that make it more fit than other individuals b. cannot occur in environments influenced by humans c. is possible only when there is no mutation

a. refers both to the process by which organisms become better matched to their environment and to the features of an organism that make it more fit than other individuals

The biological species concept is primarily based on: a. reproductive isolation b. phylogenetic history c. morphological differentiation

a. reproductive isolation

Human birth weight is a classic example of the result of: a. stabilizing selection b. disruptive selection c. genotype by environment interaction d. genetic drift

a. stabilizing selection

Speciation without geographic isolation is called _____________ speciation a. sympatric b. allopatric c. incomplete d. diversifying

a. sympatric

The scientific name for humans is Homo sapiens a. true b. false

a. true

Prokaryotes are classified into __________ domain(s) a. 1 b. 2 c. 3 d. 5

b. 2

Mass extinctions create conditions that promote a. Gene flow b. Adaptive radiation c. Microevolution

b. Adaptive radiation

Frequently, a group of related species will each have a unique courtship ritual that must be performed correctly for both partners to be willing to mate. Such a ritual constitutes a _______________ ____________ reproductive barrier a. Mechanical; postzygotic b. Behavioral; prezygotic c. Temporal; prezygotic

b. Behavioral; prezygotic

A classic example of microevolution is the shift in a population of moths from light colored to dark colored during the industrial revolution in England. This shift in moth color was brought about by an accumulation of soot on the trees and other vegetation around the factories of the cities. This is an example of _________________________. a.Disruptive selection b. Directional selection c. Stabilizing selection

b. Directional selection

Microevolution is a change in allele frequencies in an individual a. True b. False

b. False

Which of the following options lists taxonomic categories in the correct order from most specific to most general? a. Genus, family, class, order, phylum b. Genus, family, order, class, phylum c. Family, genus, order, phylum, class

b. Genus, family, order, class, phylum

Which variable increases the likelihood of allopatric speciation taking place more quickly? a. Lower rate of mutation b. Longer distance between divided groups c. Increased instances of individuals in each population d. Equivalent numbers of individuals in each population

b. Longer distance between divided groups

In which of the following pairs do both evolutionary processes introduce new genetic variation into a population? a. Natural selection and genetic drift b. Mutation and gene flow c. Natural selection and gene flow d. Gene flow and genetic drift

b. Mutation and gene flow

Which scientific concept did Charles Darwin and Alfred Darwin independently discover? a. Mutation b. Natural selection c. Overbreeding d. Sexual reproduction

b. Natural selection

What is the main difference between dispersal and vicariance? a. One leads to allopatric speciation, whereas the other leads to sympatric speciation b. One involves the movement of the organism, whereas the other involves a change in the environment c. One depends on a genetic mutation occurring, whereas the other does not d. One involves closely related organisms, whereas the other involves only individuals of the same species

b. One involves the movement of the organism, whereas the other involves a change in the environment

What do scientists in the field of systematics accomplish? a. Discover new fossil sets b. Organize and classify organisms c. Name new species d. Communicate Between Field Biologists

b. Organize and classify organisms

The earliest discovered fossils are of _____________ dating back to _____________ years ago a. single-celled eukaryotes; 4.5 billion b. Prokaryotes; 3.5 billion c. Algae; 1 billion

b. Prokaryotes; 3.5 billion

Speciation, or the formation of new species, is a. A form of microevolution b. Responsible for the diversity of life c. An event that has occurred only a few times in the history of the planet

b. Responsible for the diversity of life

What are the alternative scientific theories to evolution not taught in public school? a. More theories would confuse students b. There are no viable scientific alternatives c. It is against the law d. Alternative scientific theories are suppressed by the science establishment

b. There are no viable scientific alternatives

What is true about organisms that are a part of the same clade? a. They all share the same basic characteristics b. They evolved from a shared ancestor c. They all are on the same tree d. They have identical phylogenies

b. They evolved from a shared ancestor

Mass extinctions create conditions that promote___________ a. gene flow b. adaptive radiation c. microevolution

b. adaptive radiation

Uplift and formation of a mountain range divide a freshwater snail species into two isolated populations. Erosion eventually lowers the mountain range and brings the two populations together again, but when they mate, the resulting hybrids all produce sterile young. This scenario is an example of a. sympatric speciation b. allopatric speciation c. incomplete speciation

b. allopatric speciation

Cave-dwelling catfish and cave-dwelling salamanders share striking similarities: Both organisms lack pigmentation, and their eyes are reduced or absent. The most recent common ancestor to these organisms had normal pigmentation and fully developed eyes. The similarities between cave catfish and cave salamanders are an example of a. convergent homology b. analogy (converged evolution) c. Homology

b. analogy (convergent evolution)

Cave-dwelling catfish and cave-dwelling salamanders share striking similarities: Both organisms lack pigmentation, and their eyes are reduced or absent. The most recent common ancestor to these organisms had normal pigmentation and fully developed eyes. The similarities between cave catfish and cave salamanders are an example of a. convergent homology b. analogy (convergent evolution) c. homology

b. analogy (convergent evolution)

A natural disaster wiped out 80% of a population of moths, leaving behind only brown moths. This is an example of: a. natural selection b. bottleneck effect c. gene flow

b. bottleneck effect

Evolution leads towards perfection a. true b. false

b. false

Which of the following types of reproductive barriers separates a pair of insect species that could interbreed but for the fact that one lives on goldenrod plants and the other on autumn daisies in the same general area? a. Temporal isolation b. Habitat isolation c. Behavioral isolation

b. habitat isolation

Organisms that possess more than two complete sets of chromosomes are said to be a. haploid b. polyploid c. diploid

b. polyploid

Two species that sometimes mate and produce vigorous but sterile offspring are affected by a _________ a. prezygotic barrier b. postzygotic barrier

b. postzygotic barrier

Song birds only mate with with birds of their species because they have the same calls. This is a specific example of a________ barrier, called________ a. postzygotic; behavioral isolation b. prezygotic; behavioral isolation c. prezygotic; temporal isolation d. postzygotic; hybrid breakdown

b. prezygotic; behavioral isolation

The earliest discovered fossils are of ___________ dating back to _________ years ago a. single-celled eukaryotes; 4.5 billion b. prokaryotes; 3.5 billion c. algae; 1 billion d. fish; 600 million

b. prokaryotes; 3.5 billion

Two species that sometimes mate and produce vigorous but sterile offspring are affected by ______________ a. genetic isolation b. reduced hybrid fertility c. reduced hybrid viability

b. reduced hybrid fertility

The geographic isolation of a population from other members of the species and the subsequent evolution of reproductive barrier between it and the parent species describes ______________ speciation a. Punctuated b. Sympatric c. Allopatric

c. Allopatric

The process through which species not closely related may come to resemble one another if they live in a similar environment is known as a. Coevolution b. Homology c. Convergent evolution

c. Convergent evolution

What is a phylogeny a description of? a. Mutations b. DNA c. Evolutionary History d. Organisms on Earth

c. Evolutionary History

Which of the following options lists major events in the history of life on Earth in the proper order, from earliest to most recent? a. First prokaryotes, photosynthesis, colonization of land by plants and fungi, first eukaryotes b. First eukaryotes, photosynthesis, colonization of land by plants and fungi, first prokaryotes c. First prokaryotes, photosynthesis, first eukaryotes, colonization of land by plants and fungi

c. First prokaryotes, photosynthesis, first eukaryotes, colonization of land by plants and fungi

Galápagos medium ground finches are found on Santa Cruz and San Cristóbal islands, which are separated by about 100 km of ocean. Occasionally, individuals from either island fly to the other island to stay. This can alter allele frequencies of the population through which of the following mechanisms? a. Natural selection b. Genetic drift c. Gene flow d. Mutation

c. Gene flow

Under the biological species concept, a species is a group of organisms that a. are physically similar b. Live together in a location and carry out identical ecological roles c. Have the potential to interbreed in nature and produce fertile offspring

c. Have the potential to interbreed in nature and produce fertile offspring

The wing of a bird and the arm of a human are examples of________ a. Vestigal structures b. Molecular structures c. Homologous structures d. Analogous structures

c. Homologous structures

The rise of antibiotic-resistant bacteria demonstrates which of the following? a. Bacteria can mutate in order to be immune to antibiotics b. It takes decades or longer for organisms to evolve by natural selection c. Humans have provided the selection pressure that results in more harmful strains of bacteria

c. Humans have provided the selection pressure that results in more harmful strains of bacteria

Organisms that possess more than two complete sets of chromosomes are said to be a. Haploid b. Diploid c. Polyploid

c. Polyploid

Variation in human birth weights is an example of_____________ a. Disruptive selection b. Directional selection c. Stabilizing selection

c. Stabilizing selection

Genetic drift resulting from a disaster that drastically reduces population size is called a. Natural selection b. Gene flow c. The bottleneck effect d. The founder effect

c. The Bottleneck Effect

Which statement about analogies is correct? a. They occur only as errors b. They are synonyms with homologous traits c. They are derived by response to similar environmental pressures d. They are a form of mutation

c. They are derived by response to similar environmental pressures

In a population of finches, birds with small, thick beaks can efficiently crack the seeds of one species of plant, while birds with long, thin beaks can efficiently crack the seeds of another plant species. Birds with medium-sized beaks cannot efficiently eat either kind of seed. After many generations, the distribution of beak size in these birds will be _______________ because of ___________________ a. linear; balancing selection b. normal; stabilizing selection c. U-shaped (beaks at the low and high extremes of beak size); disruptive selection

c. U-shaped (beaks at the low and high extremes of beak size); disruptive selection

Microevolution is defined as: a. a progressive "ladder" of changes from most primitive organisms to most advanced organisms b. a change in a physical trait of an individual during its lifetime c. a change in the frequency of alleles in a population over time

c. a change in the frequency of alleles in a population over time

Which of the following reproductive barriers prevents individuals of different species from mating with each other? a. hybrid inviability b. hybrid sterility c. behavioral isolation

c. behavioral isolation

_________________ selection favors organisms with phenotypes that are at one extreme relative to the average phenotype a. stabilizing b. disruptive c. directional

c. directional

Which of the following options lists major events in the history of life on Earth in the proper order, from earliest to most recent? a. first prokaryotes, photosynthesis, colonization of land by plants and fungi, first eukaryotes b. first eukaryotes, photosynthesis, colonization of plants and fungi, first prokaryotes c. first prokaryotes, photosynthesis, first eukaryotes, colonization of land by plants and fungi

c. first prokaryotes; photosynthesis; first eukaryotes; colonization of land by plants and fungi

Which of the following is not an example of evolution? a. bacteria can become resistant to antibiotics over time b. mosquito populations have become resistant to pesticides like DTT over time c. humans exposed to high levels of radiation have a higher risk of cancer

c. humans exposed to high levels of radiation have a higher risk of cancer

The rise of antibiotic-resistant bacteria demonstrates which of the following? a. bacteria can mutate in order to be immune to antibiotics b. it takes decades or longer for organisms to evolve by natural selection c. Humans have provided the selection pressure that results in more harmful strains of bacteria

c. humans have provided the selection pressure that results in more harmful strains of bacteria

Which of the following types of reproductive barriers separates two flowering plant species that could interbreed but for the fact that one has a deep flower tube and is pollinated by bumblebees whereas the other has a short, narrow flower tube and is pollinated by honeybees? a. habitat isolation b. behavioral isolation c. mechanical isolation d. gametic isolation

c. mechanical isolation

The emergence of a new plant species over a brief period of time followed by a long period of little change is consistent with which of the following theories? a. the gradual model of speciation b. allopatric speciation c. punctuated equilibrium d. adaptive radiation

c. punctuated equilibrium

Natural selection acts on genetic variation. The ultimate source of genetic variation is mutation in the DNA (or RNA in some organisms). However in sexually reproducing organisms with long generation time what process(es) account(s) for individual variation? a. Random fertilization b. Crossing over c. Independent assortment d. All of the above

d. All of the above

Which of the following are lines of evidence supporting the theory of evolution by natural selection? a. The fossil record b. Comparative anatomy and embryology c. Molecular biology (DNA sequence comparisons) d. All of the above

d. All of the above

The fact that DNA sequences are more similar in more closely related organisms is evidence of what? a. Optimal design in organisms b. Adaption c. Mutation d. Descent with modification

d. Descent with modification

Which statement about the taxonomic classification system is correct? a. There are more domains than kingdoms b. Kingdoms are the top category of classification c. A phylum may be represented in more than one kingdom d. Species are the most specific category of classification

d. Species are the most specific category of classification

Which of the following are lines of evidence supporting the theory of evolution by natural selection? a. the fossil record b. comparative anatomy and embryology c. molecular biology (DNA sequence comparisons) d. all of the above

d. all of the above

Which of the following conditions are necessary for natural selection: a. variation for a trait b. heritability of the trait c. differential reproductive success (fitness) d. all of the above

d. all of the above

Which of the following types of reproductive barriers separates two species of sea cucumbers whose sperm and eggs often bump into each other but do not cross-fertilize because of incompatible proteins on their surfaces? a. temporal isolation b. habitat isolation c. mechanical isolation d. gamete incompatibility

d. gamete incompatibility

Explain your reasoning

Black moths are visible on lighter tree branches/trunks. Speckled moths are visible on dark tree branches/trunk.

Which form of the peppered moth do you think has higher mortality in forests in unpolluted areas where tree trunks and branches? Black or speckled? Which form of the peppered moth do you think had higher mortality in forests in areas where air pollution had resulted in dark tree trunks and branches? Black or speckled?

Black; speckled

In what levels are cats and dogs considered to be part of the same group?

Cats and dogs are part of the same group at five levels: both are in the domain Eukarya, the kingdom Animalia, the phylum Chordata, the class Mammalian, and the order Carnivora

List three components of sexual reproduction (including production of gametes) that contribute to genetic variation

Crossing over, random fertilization, and independent assortment of chromosomes

Suggest one way that a snail with pigment cups could benefit from being able to detect which direction light is coming from.

Directed movements to find food and/or escape predators

The word "theory" in theory of evolution is best replaced by ______________ a. fact b. Hypothesis c. Idea d. Alternate explanation

a. Fact

Which of the following taxonomic levels is most inclusive? a. Kingdom b. Phylum c. Class d. Order

a. Kingdom

Which of the following taxonomic levels is most exclusive? a. phylum b. order c. genus

c. genus

A monophyletic group is a ____________ a. Phylogenetic tree b. Shared derived trait c. Character size d. Clade

d. Clade