Podcast
Questions and Answers
What was Darwin's 'mystery of mysteries'?
What was Darwin's 'mystery of mysteries'?
Speciation
Define speciation.
Define speciation.
The process by which 1 species splits into 2 or more species
Define microevolution.
Define microevolution.
Changes in allelic frequencies over generations
Define macroevolution.
Define macroevolution.
Signup and view all the answers
Define species.
Define species.
Signup and view all the answers
What is required for the formation of new species?
What is required for the formation of new species?
Signup and view all the answers
What are hybrids?
What are hybrids?
Signup and view all the answers
Explain the two types of reproductive isolation.
Explain the two types of reproductive isolation.
Signup and view all the answers
Explanation and example of habitat isolation.
Explanation and example of habitat isolation.
Signup and view all the answers
Explanation and example of temporal isolation.
Explanation and example of temporal isolation.
Signup and view all the answers
Explanation and example of behavioral isolation.
Explanation and example of behavioral isolation.
Signup and view all the answers
Explanation and example of mechanical isolation.
Explanation and example of mechanical isolation.
Signup and view all the answers
Explanation and example of gametic isolation.
Explanation and example of gametic isolation.
Signup and view all the answers
Explanation and example of reduced hybrid viability.
Explanation and example of reduced hybrid viability.
Signup and view all the answers
Explanation and example of reduced hybrid fertility.
Explanation and example of reduced hybrid fertility.
Signup and view all the answers
Explanation and example of hybrid breakdown.
Explanation and example of hybrid breakdown.
Signup and view all the answers
What type of speciation is caused by a barrier such as the Grand Canyon?
What type of speciation is caused by a barrier such as the Grand Canyon?
Signup and view all the answers
Sympatric speciation occurs in populations that live in the same geographic area. How is this possible?
Sympatric speciation occurs in populations that live in the same geographic area. How is this possible?
Signup and view all the answers
Explain what happens in sexual selection, and how this process can drive sympatric speciation.
Explain what happens in sexual selection, and how this process can drive sympatric speciation.
Signup and view all the answers
Define hybrid zones.
Define hybrid zones.
Signup and view all the answers
Define punctuated equilibrium.
Define punctuated equilibrium.
Signup and view all the answers
What is macroevolution?
What is macroevolution?
Signup and view all the answers
Which is one way that the skulls of adult chimpanzees and humans differ?
Which is one way that the skulls of adult chimpanzees and humans differ?
Signup and view all the answers
'Allometric' growth refers to?
'Allometric' growth refers to?
Signup and view all the answers
Variations in allometric growth patterns demonstrate how?
Variations in allometric growth patterns demonstrate how?
Signup and view all the answers
The biological species concept is not useful for organisms known only from fossils because?
The biological species concept is not useful for organisms known only from fossils because?
Signup and view all the answers
The largest unit in which gene flow can readily occur is a?
The largest unit in which gene flow can readily occur is a?
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?
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?
Signup and view all the answers
The fetal skulls of chimpanzees and humans both have?
The fetal skulls of chimpanzees and humans both have?
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?
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?
Signup and view all the answers
Which of the following factors would not contribute to allopatric speciation?
Which of the following factors would not contribute to allopatric speciation?
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?
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?
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?
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?
Signup and view all the answers
Which of the following applies to both anagenesis and cladogenesis?
Which of the following applies to both anagenesis and cladogenesis?
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?
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?
Signup and view all the answers
Which of the following statements about species, as defined by the biological species concept, is correct?
Which of the following statements about species, as defined by the biological species concept, is correct?
Signup and view all the answers
What is generally true of two sibling species?
What is generally true of two sibling species?
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?
Which of the various species concepts identifies species based on the degree of genetic exchange between their gene pools?
Signup and view all the answers
For which two species concepts are anatomical features the primary criterion for determining species identities?
For which two species concepts are anatomical features the primary criterion for determining species identities?
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?
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?
Signup and view all the answers
What was the species concept used by Linnaeus?
What was the species concept used by Linnaeus?
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?
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?
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?
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?
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?
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?
Signup and view all the answers
Two species of orchids with different floral anatomy.
Two species of orchids with different floral anatomy.
Signup and view all the answers
Two species of trout that breed in different seasons.
Two species of trout that breed in different seasons.
Signup and view all the answers
Two species of meadowlarks with different mating songs.
Two species of meadowlarks with different mating songs.
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.
Two species of garter snakes live in the same region, but one lives in water and the other lives on land.
Signup and view all the answers
Two species of pine shed their pollen at different times.
Two species of pine shed their pollen at different times.
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?
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?
Signup and view all the answers
The scarlet oak is adapted to moist bottomland, whereas the black oak is adapted to dry upland.
The scarlet oak is adapted to moist bottomland, whereas the black oak is adapted to dry upland.
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?
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?
Signup and view all the answers
Theoretically, the production of sterile mules by interbreeding between female horses and male donkeys should?
Theoretically, the production of sterile mules by interbreeding between female horses and male donkeys should?
Signup and view all the answers
The biological species concept is inadequate for grouping?
The biological species concept is inadequate for grouping?
Signup and view all the answers
Races of humans are unlikely to evolve extensive differences in the future for which of the following reasons?
Races of humans are unlikely to evolve extensive differences in the future for which of the following reasons?
Signup and view all the answers
The Hawaiian islands are a great showcase of evolution because of intense?
The Hawaiian islands are a great showcase of evolution because of intense?
Signup and view all the answers
All of the following have contributed to the diversity of organisms on the Hawaiian archipelago except that?
All of the following have contributed to the diversity of organisms on the Hawaiian archipelago except that?
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?
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?
Signup and view all the answers
A rapid method of speciation that has been important in the history of flowering plants is?
A rapid method of speciation that has been important in the history of flowering plants is?
Signup and view all the answers
Which example below will most likely guarantee that two closely related species will remain distinct biological species?
Which example below will most likely guarantee that two closely related species will remain distinct biological species?
Signup and view all the answers
Autopolyploidy is a speciation process that begins with an event during?
Autopolyploidy is a speciation process that begins with an event during?
Signup and view all the answers
Which of the following is a way that allopolyploidy can most directly cause speciation?
Which of the following is a way that allopolyploidy can most directly cause speciation?
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?
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?
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?
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?
Signup and view all the answers
A defining characteristic of allopatric speciation is?
A defining characteristic of allopatric speciation is?
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?
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?
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?
According to the concept of punctuated equilibrium, the 'sudden' appearance of a new species in the fossil record means that?
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?
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?
Signup and view all the answers
Which of the following would be a position held by an adherent of the punctuated equilibrium theory?
Which of the following would be a position held by an adherent of the punctuated equilibrium theory?
Signup and view all the answers
Speciation occurs via anagenesis and cladogenesis, but only the latter increases biodiversity.
Speciation occurs via anagenesis and cladogenesis, but only the latter increases biodiversity.
Signup and view all the answers
The origin of a new plant species by hybridization coupled with nondisjunction is an example of?
The origin of a new plant species by hybridization coupled with nondisjunction is an example of?
Signup and view all the answers
Which of the following would be an example of macroevolution?
Which of the following would be an example of macroevolution?
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?
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?
Signup and view all the answers
If one organ is an exaptation of another organ, then what must be true of these two organs?
If one organ is an exaptation of another organ, then what must be true of these two organs?
Signup and view all the answers
Which of the following examples would be most likely to result in macroevolution?
Which of the following examples would be most likely to result in macroevolution?
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?
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?
Signup and view all the answers
The existence of evolutionary trends, such as increasing body sizes among horse species, is evidence that?
The existence of evolutionary trends, such as increasing body sizes among horse species, is evidence that?
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.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
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.
