Unit 4 Exam Review Questions Flashcards
(67 cards)
1
Q
Traits (including behavioral traits and reproductive traits, etc.) can be explained
by some combination of three proximate causes; what are they?
A
Genes, culture, environment
2
Q
Why would “slower reproduction” or “fewer offspring” ever be favored?
A
In competitive or resource-poor environments, higher quality offspring are
strongly favored
When adult survival rate is high, it is generally beneficial to fitness to
reduce reproductive rate.
3
Q
Why would “shorter life span” ever evolve?
A
If the probability of being eaten by a predator is high, selection will favor
fast early reproduction, and it will be ineffective at weeding out late-acting
lethal alleles that arise.
4
Q
Slower life histories are associated with:
A
Longer lifespan, decreased investment in reproduction relative to growth
and maintenance
5
Q
If a new predator is introduced, which of these do you predict will be part of the
evolutionary response of the prey species? (hint: see guppy slide in lecture)
A
Decreased generation time
6
Q
Which best explains the grandmother hypothesis for long human female lifespan
relative to other great ape species?
A
Grandmaternal care increased fitness of grand offspring, increasing the
inclusive fitness of individuals who provided it, causing selection against
late-acting deleterious alleles
7
Q
Many species (esp. plants and insects) have incredibly short lifespans, measured
in days or weeks. Which idiom (or song lyric) is accurately applied to explain why
old age is lost in short-lived species?
A
Use it or lose it
8
Q
- What evolutionary force is the primary cause of late-acting lethal or semi-lethal genes increasing in frequency if late reproduction does not contribute to fitness?
A
a. Genetic drift
9
Q
- What does a life table show?
A
b. Proportion of individuals surviving to each age class and average rate of reproduction at that age class
10
Q
- Ultimately, why has cooperative behavior evolved? (choose the best explanation)
A
c. Because it increased the fitness of the allele(s) that causes cooperative behavior.
11
Q
- Under what circumstances should cooperative behaviors evolve and be expressed?
A
d. When centrifugal forces outweigh repellent forces plus dispersive forces
12
Q
- What is inclusive fitness?
A
a. The sum of direct fitness and indirect fitness
13
Q
- What is kin selection?
A
e. Natural selection on the inclusive fitness of individuals.
14
Q
- Which type of altruism (or apparent altruism) should not evolve, except possibly as a side consequence of other behaviors that provide a fitness advantage?
A
b. Indiscriminate altruism
15
Q
- Which one is Hamilton’s Rule?
A
a. “An altruistic trait can increase in frequency if the benefit (b) received by the donor’s relatives, weighted by their relationship (r) to the donor, exceeds the cost (c) of the trait to the donor’s fitness.”
16
Q
- In reference to the evolution of behaviors, what is an evolutionary stable strategy (ESS)?
A
a. “A strategy such that, if all the members of a population adopt it, then no mutant strategy could invade under the influence of natural selection.”
17
Q
- Deceptive behavioral traits (i.e. lying) can evolve under what constraint?
A
d. They must remain at low frequency relative to honest signals.
18
Q
- The field of evolutionary psychology emerged to prominence after the influential last chapter of E. O. Wilson’s book, Sociobiology, in 1975. This field is concerned with making and testing predictions that are consistent with one overarching explanation for human behavioral traits. What is that explanation?
A
b. Natural selection has favored alleles that underpin behavioral traits that increase fitness relative to alternative behaviors
19
Q
- Why do male turkeys cooperate on displays even though only one of the cooperating males receives mating opportunities as a result of those displays? (hint: see textbook section 13.2)? (answer this in words that you will be ready for a multiple-choice question about this topic that may appear on the test).
A
More likely to increase the fitness through presenting themselves together since the dominant male will increase his fitness and because these brothers share DNA- it increases the indirect fitness of the subordinate brother that doesn’t end up mating.
20
Q
- Why do evolutionary psychologists think that adoption rates of non-related children are high in Tropical Pacific Island nations?
A
c. Because, during the evolution of island populations, nearby orphans were usually related to potential adoptive parents, so allelic variants that increased the tendency to adopt were associated with higher inclusive fitness.
21
Q
- In spring, 2024, a new organelle called a nitroplast was discovered in eukaryotic, single-celled marine alga that also contain mitochondria and chloroplasts. Its function is to make nitrogen available for photosynthesis without help from an exogenous prokaryotic symbiont. Here is a link to the paper: https://www.science.org/doi/10.1126/science.adk1075 What does this discovery tell us about evolution?
A
b. That endosymbiogenesis has occurred multiple times, each time fusing lineages of prokaryotes and eukaryotes to make key energetic innovations.
22
Q
- Which is not an evolutionary transition that occurred along the lineage leading to Homo sapiens?
A
d. Loss of tail.
23
Q
- What is the closest living relative to Homo sapiens?
A
b. The clade containing chimpanzee and bonobo
24
Q
- Which trait is unique to Homo sapiens
A
e. None of the above.
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7. The foramen magnum is the hole in the base of the skull through which the spinal cord passes. How and why did the position of the foramen magnum change during the evolution of hominins?
d. Shifted anteriorly due to evolutionary shift to bipedality.
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8. The human brain is approximately how many times larger than expected for a primate of similar size / how many times larger than expected for a mammal of similar size?
a. 3 / 5
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9. Modern Homo sapiens originated in Africa and dispersed to the rest of the world in the last 70,000 years. But since the divergence from non-hominin great apes (~7 Ma), other hominin species were mostly on what continent?
e. Nope none of those, they were also in Africa
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10. Over the first ~5 million years out of ~7 million years since divergence from the common ancestor of humans and chimps, the hominin radiation has been characterized by:
a. Skull shape diversification and multiple, contemporaneous species on the same continent, sometimes even in the same habitats.
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11. During the last 2 million years of hominin evolution, at least 4 dispersal events occurred out of Africa: which of these was not part of the 4?:
c. Homo floresiensis (‘hobbit man’) dispersing to Indonesia, ~20 Ka.
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How can we best describe hominin brain size evolution from Australopithecus to the present
c. Rapid, exponential increase from ~3 Ma to the present.
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13. Clovis spearpoints were discovered in the 1930’s near Clovis, NM, and provided evidence of technological innovation in the Americas from ~13,500 years ago. Now, in the 2020’s, new evidence has emerged from New Mexico: footprints at White Sands National Park that have been dated to ~21–23,000 years old. Why is this significant for our understanding of the timing of dispersal of modern Homo sapiens around the world?
b. It means that Homo sapiens must have crossed Beringia (from Asia to North America) >21,000 years ago, less than 50 Ka after dispersing out of Africa.
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14. The ‘mitochondrial eve’ for non-African human populations, a single woman who lived approximately___ years ago, held the mitochondrial DNA haplotype that would be ancestor to mitochondrial DNA found in all non-African humans.
c. 70 Ka
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15. Which statement best describes the degree of genetic isolation among Neanderthals, Denisovans, and modern humans during the first 30 Ka after the dispersal of modern humans out of Africa?
d. All three taxa interbred and exchanged genes in both directions, many of which were functional and associated with known adaptations
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16. The ‘mitochondrial eve’ for all modern human populations, a single woman who lived approximately___ years ago, held the mitochondrial DNA haplotype that would be ancestor to mitochondrial DNA found in all modern humans around the world, including Africa.
c. ~200 Ka
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18. Why did modern humans ultimately outcompete neanderthals? (hint: neanderthals had larger brains than modern humans)
b. Another reason, unrelated to brain size
36
19. Some of the great complexity of human language is made possible by the great variety of sounds made in human speech. Our vocal versatility is possible only because of changes in our vocal tract that evolved after humans diverged from other apes. Our larynx is deeper in the throat, and the tongue curves down into the throat. This produces an L-shaped vocal tract that enables us to produce a remarkable diversity of sounds. But this comes at a cost (a testament to the strong fitness advantage of complex spoken language). What is this cost?
b. Choking susceptibility
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17. Why do humans eat honey? Provide a proximate reason (direct cause of human behavioral choice) and an ultimate (evolutionary causes governing modern preferences) reason. (open ended question; think about this so you can be prepared if it appears in multiple choice form on the exam)
It's a sweet treat that activates the dopamine receptors in the brain and can give energy after consumption.
This release of energy can allow the individual perform better in terms of survival and lead to the possibility of increasing ones fitness.
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2. Approximately what proportion of the human gene pool is variable?
c. 1/1000
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3. Of all standing genetic variation in the human gene pool, what proportion, x, is shared among all extant populations of modern humans? (hint: 1/x = the proportion of variation that is represents differences among or between populations?
e. 0.88
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4. What is one way in which can we tell that modern humans underwent successive genetic bottlenecks during colonization of the world following the dispersal event out of Africa at ~70,000 years ago?
b. Genetic load increases with increasing distance from Africa
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5. Agricultural evolution: Humans invented crop-based agriculture by artificially selecting plants for desirable properties (plant domestication, an evolutionary process). Approximately where and when did this occur? (note: textbook says 11 Ka in one instance and 16 ka in another — don’t worry about this distinction, and recall that there is uncertainty around genetic and archaeological evidence).
c. Between ~16 Ka and ~2 Ka, on at least 5 continents and several major islands.
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6. Lactase persistence: The evolution of agriculture and the resulting dietary shifts left a clear mark on the human gene pool. Comparing ancient versus modern genomes in European humans shows dramatic allele frequency differences over just a couple of thousand years. The allele for lactase persistence that arose in Europe showed the most striking signature of natural selection. What does this gene do?
d. Causes persistent expression of the lactase enzyme into adulthood, allowing for lifelong consumption of dairy products.
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7. Are humans still evolving by natural selection? (Hint: study the two examples provided: height and cholesterol)
e. Yes, natural selection is still occurring, shaping the modern human gene pool.
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8. Ongoing natural selection on human traits such as height and blood-cholesterol levels have been demonstrated. What evidence needs to be gathered in order to demonstrate that natural selection is occurring in these cases?
a. Heritability of the trait and its effect on lifetime reproductive output.
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9. According to the Hygiene Hypothesis, what is sometimes necessary:
d. Reintroducing the full community of microbes to suppress harmful microbial species.
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10. Skin color evolution: [open-ended question] Why does the optimum level of skin melanin for any human population depend on the level of UV radiation in their local environment? To answer this question, you must explain why dark skin evolved in our ancestral lineage (the ‘naked ape’ hypothesis) and why light skin evolved at least 3 independent times after modern humans expanded out of Africa at 70 Ka. (hint: Vitamin D and folate should be part of your answer).
dark skin = natural sunscreen that prevented to breakdown of folate (Necessary and beneficial vitamin)
light skin evolved= increased the amount of UV that could be absorbed and therefor vitamin D
47
2. Where did the Covid-19 pandemic start and how do we know? (hint: horseshoe bats are mostly insectivorous)
b. Wuhan’s Huanan Seafood Market; abundant direct evidence of various types.
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3. SARS-CoV-2 lineages found in wild horseshoe bat populations shared a common ancestor with the lineages that started the pandemic approximately how long before the pandemic started?
b. Approximately one year or possibly up to three years
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4. The presence of SARS-CoV-2 in a variety of intermediate host species and its secondary infection of many non-human mammal species as a result of the human pandemic shows that this virus is a…
c. Host generalist.
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5. The dramatically rapid replacement of successive clades of SARS-CoV-2 during the pandemic shows a powerful example of what:
a. Evolution by natural selection
51
6. The 32 substitutions in the spike protein that characterize the omicron variant suggest a period of what?
a. Relaxed selection in immunocompromised hosts
52
7. Serological evidence from before the start of the SARS-CoV-2 pandemic shows the extent to which the general population of Asia had been exposed to SARS and related coronaviruses. In general, the population (including Wuhan, China, residents), showed no antibodies, indicating no exposure. However, people involved in the animal trade and working at wet markets throughout tropical Southeast Asia showed high prevalence of antibodies, indicating previous exposure. What does this mean?
a. Zoonotic host switches from animals to people occur all the time when wild animals and humans come into contact, but those exposure or transmission events just don’t usually lead to pandemic-scale spread.
53
8. Geographic analysis of Covid-19 cases at the start of the pandemic shows a high concentration, with subsequent spread, from what locality within Wuhan? (hint: this is one of many strong pieces of evidence that a zoonotic transmission event triggered the pandemic, not a lab leak).
c. Huanan Seafood Market
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2. In a survey across 33 countries, which pair of countries have <50% of residents answering that evolution is true (as opposed to false, or not sure)?
e. United States and Turkey
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3. Teaching religious alternatives to evolution in public school science classrooms is unconstitutional because it violates the __________________ of the United States Constitution, written by James Madison.
a. Establishment Clause
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4. Which objection to the theory of evolution is true?
b. Evolution conflicts with a literal interpretation of the Bible
57
5. Which is an appropriate approach to public science education?
d. Teach the evidence-based theories that have been repeatedly scrutinized and vetted by research and the peer review process.
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6. Why do some people (including about half of Americans) believe evolution is false?
b. They favor their specific religious beliefs over scientific evidence.
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7. For variable genes such as MHC loci that are subject to balancing selection, gene trees of segregating variants can show that they are mixed up between humans and chimpanzees — what does this show about evolution?
b. that the ancestral alleles had already diversified in the common ancestor of humans and chimpanzees and that >7-million year old diversity had been retained.
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8. What is the core tenet of the Intelligent Design concept?
b. that supernatural intervention is required to account for the origins and forms of living things
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9. Which of these structures is irreducibly complex?
e. None of the above.
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10. The building blocks for complex functional biochemical structures or pathways usually come from…
a. Random sequences in the genome that become bioactive
b. Repurposing of existing proteins for new functions
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11. Which flow best describes the scientific process?
b. Novel claim research peer review scientific consensus -> textbooks and classrooms
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12. How do religious evolutionary biologists tend to reconcile evolution with religion?
c. God who set a process in motion.
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13. What best describes evolution?
c. A theory and a fact
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14. As of 2018, what were the approximate proportions of Americans who believed that humans were created in more or less their current form without any supernatural forces / humans evolved but in a way that was guided by god or a higher power / humans evolved from simpler lifer forms, respectively?
b. 18 / 48 / 33
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15. Which flow best describes the aspirations of Intelligent Design proponents to affect public education?
a. Novel claim textbooks and classrooms
