Textbook Question
How do copy-number variants arise? Do they account for more polymorphism than SNPs within the human population?
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Ch. 20 - Population Genetics and Evolution at the Population, Species, and Molecular Levels
Sanders3rd EditionGenetic Analysis: An Integrated ApproachISBN: 9780135564172
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Table of contents
- Ch. 1 - The Molecular Basis of Heredity, Variation, and Evolution64
- Ch. 2 - Transmission Genetics144
- Ch. 3 - Cell Division and Chromosome Heredity81
- Ch. 4 - Gene Interaction87
- Ch. 5 - Genetic Linkage and Mapping in Eukaryotes103
- Ch. 6 - Genetic Analysis and Mapping in Bacteria and Bacteriophages73
- Ch. 7 - DNA Structure and Replication71
- Ch. 8 - Molecular Biology of Transcription and RNA Processing79
- Ch. 9 - The Molecular Biology of Translation110
- Ch. 10 - Eukaryotic Chromosome Abnormalities and Molecular Organization100
- Ch. 11 - Gene Mutation, DNA Repair, and Homologous Recombination86
- Ch. 12 - Regulation of Gene Expression in Bacteria and Bacteriophage90
- Ch. 13 - Regulation of Gene Expression in Eukaryotes38
- Ch. 14 - Analysis of Gene Function via Forward Genetics and Reverse Genetics72
- Ch. 15 - Recombinant DNA Technology and Its Applications69
- Ch. 16 - Genomics: Genetics from a Whole-Genome Perspective49
- Ch. 17 - Organelle Inheritance and the Evolution of Organelle Genomes27
- Ch. 18 - Developmental Genetics43
- Ch. 19 - Genetic Analysis of Quantitative Traits66
- Ch. 20 - Population Genetics and Evolution at the Population, Species, and Molecular Levels105
Sanders3rd EditionGenetic Analysis: An Integrated ApproachISBN: 9780135564172Not the one you use?Change textbook
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Sanders 3rd EditionCh. 20 - Population Genetics and Evolution at the Population, Species, and Molecular LevelsProblem D.9
Sanders 3rd EditionCh. 20 - Population Genetics and Evolution at the Population, Species, and Molecular LevelsProblem D.9Chapter 20, Problem D.9
How can ancient DNA provide insight into past migrations that analyses of extant human genomes fail to uncover?
Verified step by step guidance1
Understand that ancient DNA (aDNA) refers to genetic material extracted from the remains of organisms that lived in the past, often thousands of years ago, providing a direct snapshot of genetic variation at specific points in history.
Recognize that analyses of extant (currently living) human genomes only reflect the genetic diversity of present-day populations, which may have been shaped by recent migrations, genetic drift, and admixture events, potentially obscuring older migration patterns.
Learn that by comparing ancient DNA sequences with those of modern populations, researchers can identify genetic lineages and population structures that no longer exist or are rare today, revealing migration events that left little or no trace in modern genomes.
Use ancient DNA to track changes in allele frequencies over time and to detect the arrival or disappearance of genetic variants associated with specific geographic regions, thereby reconstructing migration routes and timings more accurately.
Combine ancient DNA data with archaeological and environmental evidence to build a comprehensive picture of human migration history, overcoming limitations of studies based solely on extant genomes.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Ancient DNA (aDNA) Analysis
Ancient DNA refers to genetic material extracted from archaeological and historical specimens. It allows direct study of past populations, revealing genetic information that predates modern groups. This helps reconstruct evolutionary history and population dynamics that are not evident from living genomes alone.
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Limitations of Extant Human Genome Analysis
Analyses of modern human genomes reflect only surviving lineages and recent admixture events, potentially missing extinct or rare ancestral populations. Genetic drift, bottlenecks, and gene flow can obscure signals of ancient migrations, making it difficult to fully reconstruct past demographic events using only current genomes.
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Population Migration and Genetic Signatures
Migrations leave distinct genetic markers such as haplogroups and allele frequency shifts in populations. Ancient DNA can capture these signatures directly from past individuals, providing clearer evidence of migration routes, timing, and interactions between groups that may be diluted or lost in modern populations.
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Related Practice
Textbook Question
Consider possible societal and ethical dilemmas that might arise if we currently shared the planet with another hominin.
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Textbook Question
Describe how selection at a locus can result in a loss of polymorphism surrounding the locus.
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Textbook Question
Denisovans are known from bones found in Denisova Cave in the Altai Mountains in Siberia, but traces of their DNA are found in Australians and Melanesians, whose ancestors likely migrated across Asia much farther to the south. How can these geographic differences be reconciled?
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Textbook Question
In Island Melanesia and Polynesia, most mtDNA haplotypes are of Asian ancestry, whereas Y chromosome haplotypes are predominantly New Guinean. Provide a hypothesis for this sex-biased distribution.
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Textbook Question
When the human genome is examined, the chromosomes appear to have undergone only minimal rearrangement in the 100 million years since the last common ancestor of eutherian mammals. However, when individual humans are examined or when the human genome is compared with that of chimpanzees, a large number of small indels and SNPs can be detected. How are these observations reconciled?
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