Speciation and Evolutionary Concepts Quiz

Questions and Answers

What was Darwin's 'mystery of mysteries'?

Speciation

Define speciation.

The process by which 1 species splits into 2 or more species

Define microevolution.

Changes in allelic frequencies over generations

Define macroevolution.

Broad pattern of evolution over long periods of time Signup and view all the answers

Define species.

A group of populations whose members have the potential to interbreed and produce viable offspring Signup and view all the answers

What is required for the formation of new species?

Reproductive isolation Signup and view all the answers

What are hybrids?

Offspring that result from an interspecific mating Signup and view all the answers

Explain the two types of reproductive isolation.

<ol> <li>Prezygotic: blocks fertilization from occurring. 2) Postzygotic: reproductive isolation after the zygote is formed</li> </ol> Signup and view all the answers

Explanation and example of habitat isolation.

<ol> <li>Two species that live in the same area but different habitats encounter each other rarely. 2) Terrestrial garter snake vs aquatic</li> </ol> Signup and view all the answers

Explanation and example of temporal isolation.

<ol> <li>Species that breed during different times of day/year etc. Gametes cannot mix. 2) Eastern spotted skunk and western spotted skunk.</li> </ol> Signup and view all the answers

Explanation and example of behavioral isolation.

<ol> <li>Mates cannot recognize each other because of different courtship rituals. 2) Blue-footed boobies have an elaborate courtship ritual.</li> </ol> Signup and view all the answers

Explanation and example of mechanical isolation.

<ol> <li>Morphological differences prevent mating. 2) Shells of two snails spiral different ways and so genital openings do not align.</li> </ol> Signup and view all the answers

Explanation and example of gametic isolation.

<ol> <li>Sperm of one species cannot fertilize egg of the other. 2) Red and purple sea urchins have different proteins on sperm and egg.</li> </ol> Signup and view all the answers

Explanation and example of reduced hybrid viability.

<ol> <li>Hybrid development is impaired. 2) Salamander hybrids cannot completely develop.</li> </ol> Signup and view all the answers

Explanation and example of reduced hybrid fertility.

<ol> <li>Hybrids are sterile. 2) Donkey + horse = sterile mule.</li> </ol> Signup and view all the answers

Explanation and example of hybrid breakdown.

<ol> <li>Mating of hybrids results in sterile or weak offspring. 2) Strains of cultivated rice breakdown over generations.</li> </ol> Signup and view all the answers

What type of speciation is caused by a barrier such as the Grand Canyon?

Allopatric Signup and view all the answers

Sympatric speciation occurs in populations that live in the same geographic area. How is this possible?

Polyploidy, sexual selection, and habitat differentiation. Signup and view all the answers

Explain what happens in sexual selection, and how this process can drive sympatric speciation.

Mate choice creates a reproductive barrier that can keep gene pools separate. Signup and view all the answers

Define hybrid zones.

Region where members of different species meet and mate. Signup and view all the answers

Define punctuated equilibrium.

Periods of apparent stasis punctuated by sudden change. Signup and view all the answers

What is macroevolution?

Evolution as it occurs on a large scale Signup and view all the answers

Which is one way that the skulls of adult chimpanzees and humans differ?

Adult chimpanzees have heavier brow ridges. Signup and view all the answers

'Allometric' growth refers to?

Variation in growth rates of various parts of the body. Signup and view all the answers

Variations in allometric growth patterns demonstrate how?

Relative small genetic change can have a major impact on phenotype. Signup and view all the answers

The biological species concept is not useful for organisms known only from fossils because?

It is not possible to test reproductive isolation in fossil forms. Signup and view all the answers

The largest unit in which gene flow can readily occur is a?

A species. Signup and view all the answers

Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species. Recently, these birds have been classified as eastern and western forms of a single species, the yellow-rumped warbler. Which of the following pieces of evidence, if true, would be cause for this reclassification?

The two forms are observed to interbreed successfully where their habitats overlap. Signup and view all the answers

The fetal skulls of chimpanzees and humans both have?

The fetal skulls of chimpanzees and humans both have small jaws. Signup and view all the answers

Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian islands have different elaborate courtship rituals that involve fighting other males and stylized movements that attract females. What type of reproductive isolation does this represent?

Behavioral isolation. Signup and view all the answers

Which of the following factors would not contribute to allopatric speciation?

Gene flow between these two populations is extensive. Signup and view all the answers

Plant species A has a diploid number of 12. Plant species B has a diploid number of 16. A new species, C, arises as an allopolyploid from A and B. The likely diploid number for species C would probably be?

<ol start="28"> <li></li> </ol> Signup and view all the answers

Mimulus lewisii and M. cardinalis are plants that do not hybridize in nature but can be readily crossed in the laboratory to produce fertile offspring. Which of the following is least likely to keep the gene pools of these two plants separate in nature?

Gametic incompatibility. Signup and view all the answers

Which of the following applies to both anagenesis and cladogenesis?

Speciation. Signup and view all the answers

A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back made possible the evolution of the tetrapod limb. This type of change is illustrative of?

Change in developmental gene. Signup and view all the answers

Which of the following statements about species, as defined by the biological species concept, is correct?

Biological species are defined by reproductive isolation and the biological species is the largest unit of population in which successful reproduction is possible. Signup and view all the answers

What is generally true of two sibling species?

They shared a common ancestor recently in evolutionary time. Signup and view all the answers

Which of the various species concepts identifies species based on the degree of genetic exchange between their gene pools?

Biological. Signup and view all the answers

For which two species concepts are anatomical features the primary criterion for determining species identities?

Morphological and ecological. Signup and view all the answers

A biologist discovers two populations of wolf spiders whose members appear identical. Members of one population are found in the leaf litter deep within a woods. Members of the other population are found in the grass at the edge of the woods. The biologist decides to designate the members of the two populations as two separate species. Which species concept is this biologist most closely utilizing?

Ecological. Signup and view all the answers

What was the species concept used by Linnaeus?

Morphological. Signup and view all the answers

You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use?

Morphological. Signup and view all the answers

Some species of Anopheles mosquito live in brackish water, some in running fresh water, and others in stagnant water. What type of reproductive barrier is most obviously separating these different species?

Habitat isolation. Signup and view all the answers

Which of the following must occur during a period of geographic isolation in order for two sibling species to remain genetically distinct following their geographic reunion in the same home range?

Reproductive isolation. Signup and view all the answers

Two species of orchids with different floral anatomy.

Mechanical. Signup and view all the answers

Two species of trout that breed in different seasons.

Temporal. Signup and view all the answers

Two species of meadowlarks with different mating songs.

Behavioral. Signup and view all the answers

Two species of garter snakes live in the same region, but one lives in water and the other lives on land.

Habitat. Signup and view all the answers

Two species of pine shed their pollen at different times.

Temporal. Signup and view all the answers

Mating fruit flies recognize the appearance, odor, tapping motions, and sounds of members of their own species. What type of reproductive isolation does this represent?

Behavioral. Signup and view all the answers

The scarlet oak is adapted to moist bottomland, whereas the black oak is adapted to dry upland.

Soils. Signup and view all the answers

Two species of frogs belonging to the same genus occasionally mate, but the offspring do not complete development. What is the mechanism for keeping the two frog species separate?

The postzygotic barrier called hybrid inviability. Signup and view all the answers

Theoretically, the production of sterile mules by interbreeding between female horses and male donkeys should?

Reinforce postzygotic barriers between horses and donkeys. Signup and view all the answers

The biological species concept is inadequate for grouping?

Asexual organisms. Signup and view all the answers

Races of humans are unlikely to evolve extensive differences in the future for which of the following reasons?

Humans are incompletely isolated. Signup and view all the answers

The Hawaiian islands are a great showcase of evolution because of intense?

Adaptive radiation and allopatric speciation. Signup and view all the answers

All of the following have contributed to the diversity of organisms on the Hawaiian archipelago except that?

The islands are very young in geologic time. Signup and view all the answers

The Galapagos archipelago appeared about 2 million years ago, when submerged volcanoes (seamounts) rose above the ocean's surface. A single hypothetical colonization event introduced a species of finch to one island in the distant past. Today, several islands in the archipelago contain unique species of finches. What must have happened following the initial colonization event to account for the current situation?

Cladogenesis, Allopatric Speciation, Adaptive Radiation. Signup and view all the answers

A rapid method of speciation that has been important in the history of flowering plants is?

Polyploidy. Signup and view all the answers

Which example below will most likely guarantee that two closely related species will remain distinct biological species?

Reproductive isolation from one another. Signup and view all the answers

Autopolyploidy is a speciation process that begins with an event during?

Meiosis. Signup and view all the answers

Which of the following is a way that allopolyploidy can most directly cause speciation?

It can overcome hybrid sterility. Signup and view all the answers

A new plant species formed from the hybridization between a plant with a diploid number of 16 and a plant with a diploid number of 12 would probably have a gamete chromosome number of?

<ol start="14"> <li></li> </ol> Signup and view all the answers

Plant species A has a diploid number of 28. Plant species B has a diploid number of 14. A new, sexually reproducing species C arises as an allopolyploid from hybridization of A and B. The diploid number of C would probably be?

<ol start="42"> <li></li> </ol> Signup and view all the answers

A defining characteristic of allopatric speciation is?

Geographic isolation. Signup and view all the answers

In the 5-6 million years that the hominid lineage has been diverging from its common ancestor with the great apes, dozens of hominid species have arisen, often with several species coexisting in time and space. As recently as 30,000 years ago, Homo sapiens coexisted with Homo neanderthalensis. Both species had large brains and advanced intellects. That these traits were common to both species is most easily explained by which of the following?

Species selection. Signup and view all the answers

According to the concept of punctuated equilibrium, the 'sudden' appearance of a new species in the fossil record means that?

A new species forms most of its unique features as it comes into existence and then changes little for the duration of its existence. Signup and view all the answers

Many species of snakes lay eggs, but in the forests of northern Minnesota where growing seasons are short, only live-bearing snake species are present. This trend toward species that?

Species selection. Signup and view all the answers

Which of the following would be a position held by an adherent of the punctuated equilibrium theory?

A new species forms its unique features as it comes into existence and then changes little for the duration of its existence. Signup and view all the answers

Speciation occurs via anagenesis and cladogenesis, but only the latter increases biodiversity.

True. Signup and view all the answers

The origin of a new plant species by hybridization coupled with nondisjunction is an example of?

Sympatric speciation. Signup and view all the answers

Which of the following would be an example of macroevolution?

Evolution of modern humans, Homo sapiens, from australopithecine ancestors. Signup and view all the answers

If the complex protein assemblage of the prokaryotic flagellum arose by the same general processes as those of the complex eyes of advanced molluscs (such as squids), then?

Ancestral versions of this protein assemblage were either less functional, or had different functions. Signup and view all the answers

If one organ is an exaptation of another organ, then what must be true of these two organs?

They are homologous organs. Signup and view all the answers

Which of the following examples would be most likely to result in macroevolution?

A change in a regulatory gene, which has a major and adaptive impact on morphology. Signup and view all the answers

A hypothetical mutation in a squirrel population produces organisms with eight legs rather than four. Further, these mutant squirrels survive, successfully invade new habitats, and eventually give rise to a new species. The initial event giving rise to extra legs would be a good example of?

Changes in homeotic genes. Signup and view all the answers

The existence of evolutionary trends, such as increasing body sizes among horse species, is evidence that?

In particular environments, similar adaptations can be beneficial in more than one species. Signup and view all the answers

Study Notes

Speciation and Evolutionary Concepts

Speciation is the process where one species splits into two or more distinct species, often referred to as Darwin's "mystery of mysteries."
Microevolution involves small-scale changes in allelic frequencies within a population over generations.
Macroevolution refers to broader patterns and processes that occur over long timescales, resulting in significant evolutionary changes.

Definitions and Mechanisms of Species

A species is defined as a group of populations where members can interbreed and produce viable offspring.
Reproductive isolation is essential for new species formation and can be classified into prezygotic (before fertilization) and postzygotic (after fertilization) isolating mechanisms.

Types of Prezygotic Isolation

Habitat isolation occurs when species occupy different habitats but live in the same area, e.g., terrestrial vs. aquatic garter snakes.
Temporal isolation happens when species breed at different times, preventing their gametes from mixing; an example includes eastern and western spotted skunks.
Behavioral isolation arises when differing courtship rituals hinder mate recognition, as seen in blue-footed boobies.
Mechanical isolation involves morphological differences that block mating, such as snails with incompatible shell spirals.
Gametic isolation is present when the sperm of one species cannot fertilize the egg of another, exemplified by red and purple sea urchins.

Types of Postzygotic Isolation

Reduced hybrid viability refers to hybrids that cannot fully develop, like certain salamander hybrids.
Reduced hybrid fertility results in sterile offspring, e.g., the mule produced by crossing a horse and a donkey.
Hybrid breakdown involves hybrids that are fertile but produce weak or sterile offspring over generations, as noted in certain rice strains.

Speciation Processes

Allopatric speciation occurs when geographical barriers lead to reproductive isolation between populations, such as the Grand Canyon.
Sympatric speciation can happen in the same geographical area, often driven by mechanisms like polyploidy, sexual selection, or habitat differentiation.

Hybrid Zones and Evolutionary Patterns

Hybrid zones are regions where distinct species interbreed, and can provide insights into genetic exchange and speciation.
Punctuated equilibrium is a model describing evolution as long periods of stability punctuated by brief, significant changes.

Species Concepts

The biological species concept identifies species based on reproductive isolation and gene flow, while the morphological species concept relies on anatomical characteristics.
The ecological species concept focuses on the interchangeable roles individuals play in their environments, particularly in different habitats.

Important Evolutionary Concepts

Anagenesis involves a single species evolving over time, while cladogenesis increases biodiversity through branching into new species.
Allopatric and sympatric speciation mechanisms demonstrate how isolation and genetic change can lead to the emergence of new species.

Historical Context and Observations

The Hawaiian Islands exhibit extensive examples of adaptive radiation and allopatric speciation due to their geological youth and isolation.
The Galapagos archipelago showcases cladogenesis and adaptive radiation where species diverged from a common ancestor.

Evolutionary Changes and Selective Pressures

Hox gene changes can significantly impact limb development, illustrating the role of developmental genes in evolution.
Exaptation refers to a trait originally evolved for one function that is co-opted for another, indicating evolutionary flexibility.

Macro and Microevolutionary Trends

Evolutionary trends can be observed through changes in populations over time, demonstrated by the evolution of modern humans from australopithecine ancestors.
Increasing body sizes among horse species serve as evidence of convergent evolution, where similar adaptations arise in different lineages.

Summary of Genetic and Reproductive Concepts

Hybrid sterility and inviability illustrate barriers that maintain species distinctiveness.
Lethal allele combinations and polyploidy can result in new species and diversification in flowering plants.

This compilation encapsulates the intricacies of speciation, evolutionary mechanisms, and the multifaceted definitions of species in biological contexts.

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Description

Test your knowledge on speciation and evolutionary mechanisms! This quiz covers key concepts like microevolution, macroevolution, and reproductive isolation. Get ready to explore the fascinating ways species evolve and diverge over time.