EEB 390 UMICH Final Exam - Winter 2025

What is phenotypic plasticity?

The ability of an organism to change its phenotype in response to environmental conditions.

What are constant traits in the context of phenotypic plasticity?

Phenotypes with fixed expression across environments.

What is the equation for phenotypic variance (VP)?

VP = VG + VE, where VG is genetic variance and VE is environmental variance.

What is a reaction norm?

The distribution of phenotypes for one genotype over a range of environmental conditions.

What does the slope of a reaction norm indicate?

The degree of plasticity of a phenotype.

What does it indicate if the slopes of reaction norms are not the same?

There is a genotype by environment interaction (GxE interaction).

What are the 'big four' environmental factors affecting phenotypic plasticity?

Diet, temperature/day length, predators/parasites, and social environment.

What are the two types of plasticity?

Reverse vs irreversible and adaptive vs non-adaptive.

What is the traditional perspective on the relationship between genes and phenotypes in evolution?

Genes 'lead' and phenotypes 'follow' in the process of adaptive evolution.

What is the alternative perspective on the relationship between genes and phenotypes?

Phenotypic variation creates conditions that result in an adaptive genetic response.

What is canalization in evolutionary biology?

The evolution of internal mechanisms that constrain plasticity to consistently produce one phenotype.

What is genetic assimilation?

When a trait that initially appears only in response to the environment becomes genetically 'hardcoded'.

What does evolvability refer to?

The capacity of a system for adaptive evolution.

What is coevolution?

Reciprocal genetic change in interacting species due to natural selection imposed by each on the other.

What are mutualistic interactions?

Interactions where the effects are positive for both species involved.

What are antagonistic interactions?

Interactions where the effects are negative for at least one species involved.

What is cospeciation?

Speciation in one species that leads to speciation in another species.

What is character displacement?

When a trait differs more between sympatric than allopatric populations of the same species.

What is mutualistic coevolution?

When each species benefits from the interaction.

What is obligate mutualism?

A type of mutualism where each partner can only survive and reproduce successfully in the presence of the other.

What is facultative mutualism?

A type of mutualism that is beneficial but not essential for survival.

What is mimicry in evolutionary biology?

A form of convergent evolution where one species resembles another for advantage.

What is Müllerian mimicry?

When multiple noxious species converge on the same warning phenotype.

What is Batesian mimicry?

When a harmless species imitates the warning phenotype of a toxic species.

What are Wallace's Three Laws of mimicry?

1. Models and mimics must be found in the same geographic area. 2. Mimicry is confined to a few groups. 3. Imitators must be less abundant than models.

What does life history refer to?

The age-and stage-specific timing of growth and reproduction events.

What is fecundity?

The reproductive rate of an organism or population, measured by the number of gametes, seed sets, or asexual propagules.

What is semelparous reproduction?

A strategy in which individuals only reproduce once in their lives.

What is iteroparous reproduction?

A strategy in which individuals reproduce more than once.

What does the cost of reproduction refer to?

The reduction of an individual's future fitness caused by reproductive activity.

What is a life table?

A mathematical framework for converting life history trait measurements into predicted rates of population increase.

What are the components of a life table?

x: stepwise age units, lx: survival to age x, mx: fecundity at age x, lxmx: reproductive success.

What is a Lack clutch?

The clutch size that maximizes the number of surviving offspring.

What is evolutionary bet-hedging?

A tradeoff between the mean and variance of fitness.

What are two ways of clutch manipulation?

Adjusting clutch size or sex ratio.

What is a 'big bang' life history strategy?

A semelparous strategy favored if there is an exponential relationship between body mass and reproductive output.

What is an evolutionary tradeoff?

An advantage of a change in one character is correlated with a disadvantage in other characters.

What does the mother hypothesis suggest?

Older females have lower overall health for reproduction, so post-reproductive females contribute to the fitness of their existing children.

What is the grandmother hypothesis?

Older mothers may help raise their grandchildren, thereby enhancing inclusive fitness.

What does the in-law hypothesis state?

Simultaneous reproduction by successive generations of in-laws lowers the survivorship of offspring.

What is senescence?

Intrinsic changes that lower survival and reproduction with age.

What are the mechanisms proposed for aging?

Mutation accumulation, pleiotropy, antagonistic pleiotropy, and the disposable soma hypothesis.

What is intragenomic conflict?

Conflict within the genome.

What is intrapspecific conflict?

Conflict within a species.

What is interspecific conflict?

Conflict between species.

What is game theory in the context of evolutionary biology?

A mathematical approach to studying behavior that solves for the optimal decision in strategic situations.

What is inclusive fitness?

The sum of direct fitness (number of viable offspring) and indirect fitness (increase in reproduction of relatives due to individual's behavior).

What is Hamilton's rule?

r × B > C, where B is the benefit to the recipient, C is the cost to the donor, and r is the relatedness.

What is parthenogenesis?

The production of offspring from unfertilized eggs.

What are the costs of sexual reproduction?

Numerical cost, search cost, genetic cost, and pathogen cost.

What is anisogamy?

The production of two different kinds of gametes (e.g., sperm and egg).

What is isogamy?

The production of one kind of gamete.

What are the benefits of sexual reproduction?

Clearance of deleterious mutations, combining beneficial mutations, and generating novel genotypes.

What is the Fisher-Muller hypothesis?

It suggests that sexual reproduction can combine beneficial mutations from different individuals, accelerating adaptive evolution.

What is Muller's ratchet?

It is the process by which the genomes of an asexual population accumulate deleterious mutations in an irreversible manner.

What are alternative mating strategies?

Divergent ways that males of the same species use to acquire mates, usually exhibiting polymorphism.

What is sperm competition?

The competitive process between spermatozoa of two or more different mates to fertilize the same egg during sexual reproduction.

What is aggressive mimicry?

When parasites or predators resemble something harmless, often described as a 'wolf in sheep's clothing'.

How are viruses classified?

Viruses do not fit neatly into classification systems used for cellular life and are classified based on phenotypes such as nucleic acid type, morphology, mode of replication, and host.

What are the characteristics of positive-sense RNA viruses?

Their genomes can act directly as mRNA.

What are the characteristics of negative-sense RNA viruses?

Their genomes must be transcribed into mRNA before they can be translated.

What type of viruses are coronaviruses?

Coronaviruses are enveloped, positive-sense RNA viruses that infect fish, amphibians, birds, and mammals.

What is the function of reverse transcriptase in retroviruses?

It produces DNA from the RNA genome of the retrovirus, allowing it to insert a DNA copy into the host cell's DNA.

What does the Escaped Gene Hypothesis propose?

It suggests that retroviruses evolved from selfish genes that developed protein coatings and self-replication.

What is the Reduction Hypothesis in the context of retroviruses?

It posits that retroviruses may have originated from extremely reduced cellular organisms.

What does the 'Virus First' Hypothesis suggest?

It proposes that retroviruses are remnants of the RNA world that existed before DNA-based life.

What defines an Emerging Infectious Disease (EID)?

An EID is a disease that has seen an increased incidence in the past 20 years.

What is pathogenicity?

Pathogenicity refers to the disease-causing capacity of pathogens.

What is spillover in epidemiology?

Spillover is the transmission of a pathogen to a novel host species.

What does phylodynamics study?

Phylodynamics refers to the genetic patterns of variation in pathogens.

What are SIR models in epidemiology?

SIR models are population growth models that categorize hosts as Susceptible, Infected, or Recovered.

How is pathogen fitness measured in epidemiological models?

It is measured by the number of secondary infections caused by a single infected host.

What does R0 (Basic Reproduction Number) indicate?

R0 indicates the number of secondary hosts infected by a single infected host.

What is virulence in the context of pathogens?

Virulence refers to the ability of a pathogen to infect and/or damage a host.

What is optimal virulence?

Optimal virulence is the equilibrium point where a parasite's fitness is maximized.

What is a super-spreader?

A super-spreader is a host that disproportionately infects more secondary contacts than other hosts.

What does the 20/80 rule in epidemiology state?

Approximately 20% of infected individuals are responsible for 80% of transmissions.

What is viral reassortment?

Viral reassortment is the mixing of genetic material from different strains within an individual.

What are incidental hosts?

Incidental hosts are organisms that get infected but are not critical to the pathogen's life cycle.

What is host immunity?

Host immunity refers to biological defenses that fight infection while maintaining tolerance to avoid allergies and autoimmune diseases.

What is the goal of Adaptive Therapy in cancer treatment?

The goal is to maintain a manageable tumor by preserving non-resistant cell types that can outcompete resistant tumor cells.

What does the Thrifty Genotype Hypothesis suggest?

It suggests that alleles advantageous in the past may be detrimental in modern lifestyles.

What is the Thrifty Phenotype Hypothesis?

It posits that limited nutrition during prenatal development leads to a lifelong 'starvation mode' physiology.

How is hominin phylogeny best described?

It resembles a 'tangled bush' or 'braided river' rather than a simple tree.

Which species had relatively larger brains, Neanderthals or modern humans?

Neanderthals had relatively larger brains.

When did Homo erectus first use fire?

Homo erectus used fire approximately 1 million years ago.

What was the significance of the invention of agriculture?

It is considered one of the most profound changes in human history, occurring between 11,000 and 5,000 years ago.

What is cultural evolution?

Cultural evolution refers to the change over time in cultural elements through single variants called memes.

How are genetic relationships between modern humans best described?

They are best described by continuous geographic patterns rather than discrete groups.