Study guide- 5

Flashcard 1
Q: When did the D. hemipeza species evolve in Hawai'i?
A: It evolved before the islands’ emergence, likely on older islands.

Flashcard 2
Q: When did D. differens and D. planitibia species evolve in Hawai'i?
A: They evolved after the islands emerged.

Flashcard 3
Q: When did D. heteroneura and D. silvestris species evolve in Hawai'i?
A: They evolved much later, after the more recent volcanic islands emerged.

Flashcard 4
Q: What hypothesis can explain the evolution of new species of fruitflies in Hawai’i?
A: The species evolved sequentially as new islands emerged, driven by ecological opportunities and geographic isolation leading to adaptive radiation.

Flashcard 5
Q: What role does the male cricket song play in species diversification?
A: Male cricket song is important for mate attraction. If a male kohelensis were introduced into the paranigra population, it would likely not mate with females due to song differences.

Flashcard 6
Q: How does sexual selection drive pre-zygotic reproductive isolation in crickets?
A: Pre-zygotic isolation occurs when differences in male song prevent females from recognizing males of another species, driven by sexual selection.

Flashcard 7
Q: What are synonymous and nonsynonymous substitutions?
A: Synonymous substitutions do not change the amino acid sequence of the protein, while nonsynonymous substitutions change the amino acid sequence.

Flashcard 8
Q: How do you calculate Ka/Ks from sequence data?
A: Ka is the rate of nonsynonymous substitutions, and Ks is the rate of synonymous substitutions. You calculate Ka/Ks to determine evolutionary pressure.

Flashcard 9
Q: How can the molecular clock be applied to date the divergence of species?
A: By comparing the number of synonymous substitutions, you can estimate the time of divergence between species using the molecular clock principle.

Flashcard 10
Q: What caused the Cambrian explosion?
A: The Cambrian explosion refers to the rapid diversification of animal phyla around 540 million years ago, driven by ecological and genetic changes.

Flashcard 11
Q: What is the definition of a biological species?
A: A biological species is a group of interbreeding natural populations that are reproductively isolated from other such groups.

Flashcard 12
Q: What is speciation?
A: Speciation is the process by which new and distinct species evolve.

Flashcard 13
Q: What is reproductive isolation?
A: Reproductive isolation is a mechanism that prevents two species from interbreeding, contributing to speciation.

Flashcard 14
Q: What is the difference between sympatric and allopatric speciation?
A: Sympatric speciation occurs in overlapping habitats, while allopatric speciation occurs when populations are geographically isolated.

Flashcard 15
Q: What is vicariance?
A: Vicariance is the geographic separation of a population due to a physical barrier, leading to speciation.

Flashcard 16
Q: What is Dobzhanski-Muller genetic incompatibility?
A: It refers to genetic incompatibilities that arise when two populations diverge, resulting in reduced fitness when hybridized.

Flashcard 17
Q: What is adaptive radiation?
A: Adaptive radiation is the rapid diversification of a species into different forms that exploit various ecological niches.

Flashcard 18
Q: What is a molecular clock?
A: A molecular clock is a technique used to estimate the timing of evolutionary events based on genetic changes.

Flashcard 19
Q: What does the Ka/Ks test measure?
A: The Ka/Ks test compares the rates of synonymous and nonsynonymous mutations to infer evolutionary pressures.

Flashcard 20
Q: What is the Cambrian explosion?
A: The Cambrian explosion refers to the rapid emergence of diverse animal phyla around 540 million years ago.

Flashcard 21
Q: How does the Pangaea fragmentation hypothesis relate to amphibian evolution?
A: If the divergence of amphibians coincides with the breakup of Pangaea, the Pangaea fragmentation hypothesis is supported.

Flashcard 24
Q: What are the major differences between Homo erectus and Homo sapiens?
A: Homo erectus had a smaller brain size, a more robust body structure, and a smaller face compared to Homo sapiens, who have a larger brain, more delicate features, and advanced cultural traits.

Flashcard 25
Q: What is the significance of the Out-of-Africa migration theory?
A: The Out-of-Africa theory suggests that modern humans originated in Africa and migrated to other parts of the world, replacing archaic human species like Neanderthals and Denisovans.

Flashcard 26
Q: What is the role of genetic data in testing human migration theories?
A: Genetic data, like allelic diversity, is used to trace human ancestry and migration patterns, supporting theories such as the Out-of-Africa hypothesis and showing differences in genetic diversity between African and non-African populations.

Flashcard 27
Q: What evolutionary significance does the Neanderthal genome have?
A: The Neanderthal genome provides evidence of interbreeding between Neanderthals and Homo sapiens, contributing to modern human genetic diversity, especially in non-African populations.

Flashcard 28
Q: How does phylogenetic reconstruction help in understanding the origins of HIV?
A: Phylogenetic reconstruction traces the evolutionary history of HIV by examining its genetic changes over time, providing insights into how it jumped from chimpanzees to humans and diversified in human populations.

Flashcard 29
Q: How does HIV evolve within a single host?
A: HIV evolves rapidly within a host due to high mutation rates, leading to different viral strains that can evade the immune system and resistance treatments over time.

Flashcard 30
Q: What is the significance of the Homo naledi fossils found in South Africa?
A: The Homo naledi fossils provide evidence of an early hominin species with a combination of primitive and advanced traits, offering insights into the complexity of hominin evolution.

Flashcard 31
Q: How does the mutation rate of HIV affect drug resistance?
A: The high mutation rate of HIV allows it to quickly develop resistance to antiviral drugs, making treatment more challenging and necessitating multi-drug therapies.

Flashcard 32
Q: What evolutionary advantage does heterozygote advantage provide in populations?
A: Heterozygote advantage can increase the survival of individuals by providing resistance to diseases or environmental pressures, as seen in the persistence of cystic fibrosis alleles due to resistance to typhoid fever.

Flashcard 33
Q: What is the relationship between Homo heidelbergensis and Neanderthals/Denisovans?
A: Homo heidelbergensis is the common ancestor of Neanderthals and Denisovans, with these lineages diverging around 500,000 years ago.

Flashcard 34
Q: Why does the evolutionary biology of HIV aid in the development of treatments?
A: Understanding the evolutionary mechanisms of HIV, such as mutation rates and resistance patterns, helps in designing drugs and treatment regimens that target different stages of the virus's life cycle and minimize resistance.

Flashcard 35
Q: What is the main factor driving the persistence of cystic fibrosis alleles in human populations?
A: The persistence is likely due to heterozygote advantage, where carriers of the cystic fibrosis allele have increased resistance to typhoid fever, providing a survival benefit.

Flashcard 36
Q: What evolutionary mechanisms contribute to the spread of HIV resistance?
A: The evolution of HIV resistance is driven by natural selection, where viral strains with mutations that evade the immune system or drugs have a higher chance of survival and transmission.

Flashcard 37
Q: How do Homo sapiens' interactions with Neanderthals and Denisovans affect their genetic legacy?
A: Homo sapiens' interbreeding with Neanderthals and Denisovans has left traces of their DNA in modern human populations, influencing traits such as immune response and adaptation to different environments.

Flashcard 38
Q: What role do mutations play in HIV's adaptation to its host?
A: Mutations allow HIV to adapt rapidly to changes in the host's immune defenses and to antiretroviral treatments, making it difficult to completely eliminate the virus.

Flashcard 39
Q: Why is HIV considered a retrovirus?
A: HIV is classified as a retrovirus because it integrates its RNA genome into the DNA of the host cell, using reverse transcriptase to convert its RNA into DNA.

Flashcard 40
Q: What evidence supports the hypothesis that human TRIM5α evolved to fight an ancient retrovirus?
A: Phylogenetic reconstruction suggests that human TRIM5α evolved to combat PtERV1, an extinct retrovirus, rather than HIV, which explains its ineffectiveness against HIV.

Flashcard 41
Q: How does the concept of "within-host natural selection" apply to HIV?
A: HIV undergoes natural selection within a host, where viral variants with mutations that allow them to evade the immune system or resist drugs have a higher survival rate and proliferate.

Flashcard 42
Q: What is the significance of multi-drug treatments in HIV management?
A: Multi-drug treatments reduce the likelihood of resistance by targeting different viral mechanisms simultaneously, making it more difficult for the virus to develop resistance to all drugs.

Flashcard 43
Q: How do evolutionary processes influence the development of HIV treatments?
A: Evolutionary processes such as viral mutation and selection pressure inform the development of HIV treatments, as they help identify which drugs or combinations are most likely to prevent or slow resistance.

Flashcard 44
Q: What is the evolutionary importance of interbreeding between Neanderthals, Denisovans, and Homo sapiens?
A: Interbreeding between these species contributed to the genetic diversity of modern humans, providing advantages in immunity and adaptation to different environments.

Flashcard 45
Q: What does the study of HIV phylogenetics reveal about virus transmission?
A: HIV phylogenetics helps trace the virus's transmission across individuals, identifying how it spreads, mutates, and adapts over time.