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What is sympatric speciation?
What is sympatric speciation?
The speciation of organisms from a single ancestor living in the same geographic region.
What does the term 'allopatric speciation' refer to?
What does the term 'allopatric speciation' refer to?
Speciation that occurs after populations become physically isolated by geographical changes.
What is one major difference between allopatric and sympatric speciation?
What is one major difference between allopatric and sympatric speciation?
Allopatric speciation occurs in geographically separated populations, while sympatric speciation occurs in populations that could share the same geographic area.
What is polyploidy?
What is polyploidy?
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What causes autopolyploidy?
What causes autopolyploidy?
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Describe allopolyploidy.
Describe allopolyploidy.
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Errors in cell division may result in sympatric speciation.
Errors in cell division may result in sympatric speciation.
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Give an example of allopolyploidy.
Give an example of allopolyploidy.
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What distinguishes autopolyploidy from allopolyploidy?
What distinguishes autopolyploidy from allopolyploidy?
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What role does sexual selection play in speciation?
What role does sexual selection play in speciation?
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How do mate selection barriers affect cichlid fish?
How do mate selection barriers affect cichlid fish?
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Study Notes
Speciation Types
- Sympatric Speciation: Organisms from a single ancestor diverge while sharing the same geographic region; involves reproductive isolation due to phenotypic changes.
- Allopatric Speciation: Occurs when populations are geographically separated, preventing gene flow; reproductive barriers arise between isolated populations.
Comparison of Speciation Types
- Similarity: Both allopatric and sympatric speciation involve reproductive barriers that lead to differences between populations.
- Difference: Allopatric speciation occurs with physical separation, while sympatric speciation takes place within overlapping geographic areas.
Chromosomal Variations
- Polyploidy: An organism with more than two full sets of chromosomes, often resulting in distinct phenotypic traits and considered a new species. It can arise through autopolyploidy or allopolyploidy.
- Autopolyploidy: Results from errors in cell division (mitosis or meiosis), where gametes have double the chromosome content of the usual gamete.
- Allopolyploidy: Involves mating between two different species, producing hybrid offspring that can lead to a new polyploid species.
Mechanisms of Speciation
- Errors in Cell Division: Genetic errors during meiosis can create diploid gametes in a typically haploid organism, promoting sympatric speciation.
- Example of Allopolyploidy: Domesticated wheat arose through allopolyploidy; it can hybridize with local wild plants, potentially becoming invasive.
Differences in Polyploidy
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Autopolyploidy vs Allopolyploidy:
- Autopolyploidy involves gametes from the same species, typically due to cell division errors that double DNA content.
- Allopolyploidy involves gametes from different species, leading to hybrid offspring and subsequent polyploid generations.
Sexual Selection in Speciation
- Sexual Selection in Cichlids: A reproductive isolation strategy where mate preferences influence the phenotypic traits of subsequent generations, resulting in sympatric speciation within cichlid fish.
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Description
Explore the fascinating concepts of sympatric and allopatric speciation, and understand how chromosomal variations like polyploidy influence the evolution of species. This quiz will test your knowledge on the differences and similarities between these modes of speciation and the mechanisms involved.
