Conservation Biology & Population Genetics: Key Concepts and Strategies

What is an extinction vortex?

A situation where small populations are prone to extinction due to inbreeding and genetic drift, leading to a positive feedback loop that further reduces population size.

What factors contribute to the vulnerability of small populations?

Inbreeding depression and reduced genetic variability prevent adaptation to changing environments.

What is effective population size (Ne)?

The size of an idealized randomly mating population that shows the same level of heterozygosity as the population of interest.

What is heterozygosity?

The fraction of individuals in a population that are heterozygous for a particular locus.

Under what conditions does Ne equal actual population size (N)?

When the population has a balanced sex ratio, all individuals contribute equally to the next generation, simultaneous births, and a constant population size over time.

What is the formula for calculating effective population size (Ne)?

Ne = 4 × Nf × Nm / (Nf + Nm), where Nf is the number of breeding females and Nm is the number of breeding males.

What is Minimum Viable Population (MVP)?

The smallest population size at which a population can sustain its numbers and survive.

What is the significance of maintaining genetic diversity in populations?

It helps prevent inbreeding and maintains the population's ability to adapt to environmental changes.

What are some threats to biodiversity?

Habitat loss, invasive species, overharvesting, pollution, acid precipitation, and biomagnification.

How does habitat loss affect species?

Changes in habitat can lead to fragmentation and prevent species from dispersing or adapting.

What is biomagnification?

The increase in concentration of a toxic substance in the tissues of organisms as it moves up trophic levels.

What is the impact of invasive species on native species?

Invasive species can increase competition for resources, predation, or parasitism, affecting native species distributions.

How does pollution affect aquatic ecosystems?

Excessive release of nitrogen and phosphates can trigger algal blooms that deplete oxygen in water.

What is acid precipitation and its effect on lakes?

Acid rain decreases the pH of lakes, negatively affecting fish populations.

What role does human activity play in biodiversity loss?

Human activities such as habitat destruction, pollution, and overexploitation threaten biodiversity.

What is inbreeding depression?

Reduced biological fitness in a population due to inbreeding, leading to lower survival and reproduction rates.

What is the relationship between population size and genetic diversity?

Smaller populations tend to have reduced genetic diversity, making them more vulnerable to extinction.

How can conservation strategies be classified?

Conservation strategies can be classified based on the level of diversity they target, such as genetic, species, or ecosystem diversity.

What is the importance of protecting biodiversity?

Protecting biodiversity is crucial for ecosystem stability, resilience, and the provision of ecosystem services.

What are the consequences of overharvesting?

Overharvesting can prevent populations from rebounding and lead to declines in species numbers.

How can conservation programs help maintain populations?

By focusing on maintaining MVP and ensuring genetic diversity, conservation programs can enhance population survival.

What is the impact of climate change on species?

Species may struggle to cope with climate change due to altered habitats and shifting ecological dynamics.

What is the Greater Prairie Chicken example in conservation biology?

In 1993, researchers introduced individuals from larger populations to increase genetic variation and help the Greater Prairie Chicken rebound from a decline.

What is the significance of calculating Ne in conservation efforts?

Calculating Ne helps assess the genetic health of a population and informs management decisions to maintain diversity.

How does male-male competition affect breeding in populations?

Dominant males may monopolize breeding opportunities, leading to an unbalanced sex ratio and affecting effective population size.

What is the primary cause of global warming?

The emission of CO2 and other greenhouse gases.

What are the three levels of biodiversity?

Genetic diversity, species diversity, and ecosystem diversity.

What does genetic diversity refer to?

Diversity within and between populations, which is crucial for microevolution.

What is species diversity?

The variety of species within an ecosystem or across the biosphere.

What is ecosystem diversity?

The variety of ecosystems and their ecological processes.

What are the three status categories for species conservation?

Collapsed, critically endangered, and endangered.

What are some human activities that threaten biodiversity?

Habitat loss, climate change, invasive species, overharvesting, and pollution.

Why is biodiversity important for humans?

It provides resources like food, medicine, and ecosystem services such as water purification and climate regulation.

What are biodiversity hot spots?

Relatively small areas with many endemic and endangered species.

What percentage of Earth's land area do biodiversity hot spots cover?

1.5% of Earth's land area contains 33% of plants, amphibians, reptiles, birds, and mammals.

What is conservation biology?

The integrated study of various biological sciences to sustain biodiversity.

What is a captive-breeding program?

A program to breed endangered species in zoos to build a healthy population before reintroduction into the wild.

What is the role of the International Potato Center (CIP)?

To enhance access to affordable nutritious food in developing countries using native potato varieties.

What is the focus of habitat conservation strategies?

Shifting from species protection to protecting entire ecosystem communities.

What is the impact of forest fragmentation on species diversity?

It negatively affects species adapted to forest interiors, leading to declines.

What is a 'no intervention' policy in national parks?

Allowing natural disturbances like floods or fires to occur without human interference.

What was the outcome of the 1988 fires in Yellowstone Park?

36% of the park burned, leading to immediate recovery and increased biodiversity.

What does IUCN stand for?

International Union for Conservation of Nature.

What is the purpose of the IUCN Red List?

To assess the global conservation status of species and identify threatened species.

What criteria does COSEWIC use to assess species in Canada?

Declining abundance, limited distribution, small population size, and threats.

What is the conservation status of the Whooping crane?

It has faced population decline due to hunting, habitat degradation, and industrial development.

What are the categories of conservation status according to COSEWIC?

Extinct, extirpated, endangered, threatened, and special concern.

What is the significance of corridors in habitat conservation?

They connect fragmented habitats, allowing species to cross obstacles and promote biodiversity.

What is the predicted extinction rate of species by 2100?

Approximately 50% of species are predicted to go extinct.

What is the impact of increased sampling efforts on conservation status assessments?

It can lead to apparent recoveries in species classified as threatened.

What is the role of conservation agencies in species management?

To coordinate research and management efforts for species with overlapping distributions.

What is the importance of emotional and cultural connections to biodiversity?

They foster a moral obligation to protect species and ecosystems.

What is population ecology?

The study of populations in relation to their environment, including influences on population density, distribution, age structure, and variations in population size.

Define population dynamics.

The study of how complex interactions between biotic and abiotic factors influence variations in population size.

What is the mark-recapture method used for?

To estimate the population size of a species when it is impossible to count all individuals.

What are the steps in the mark-recapture method?

1. Sample s individuals, 2. Mark all s individuals, 3. Release all s individuals back, 4. Resample r individuals, 5. Count the number m of re-sampled marked individuals.

What is the formula for estimating population size using the mark-recapture method?

N = (s * r) / m, where N is the estimated population size, s is the number of individuals initially marked, r is the total number of individuals captured in the second sample, and m is the number of marked individuals recaptured.

What assumptions does the mark-recapture method make?

1. Marked and unmarked individuals have the same probability of being sampled, 2. Marking does not affect re-sampling probability, 3. Marked individuals mix back into the population, 4. No births, deaths, immigration, or emigration during the re-sampling interval.

What is demography?

The study of changes over time in the vital statistics of populations, especially birth rates and death rates.

What is a life table?

A table that summarizes the survival and reproduction rates of individuals in specific age groups in a population.

What is a survivorship curve?

A graph that shows the proportion of individuals in a cohort that are still alive at each age.

Describe Type I survivorship curve.

Characterized by low death rates of juveniles and adults, followed by a rapid increase in death rates in old age (e.g., mammals).

Describe Type II survivorship curve.

Characterized by a constant death rate throughout the organism's lifespan (e.g., some birds).

Describe Type III survivorship curve.

Characterized by high mortality for the young, followed by a flattening of the death rate in adults (e.g., many fish).

What is exponential population growth?

Growth of a population in an ideal, unlimited environment, represented by a J-shaped curve when population sizes are plotted over time.

What is the formula for exponential population growth?

dN/dt = rN, where dN/dt is the rate of change in population size, r is the intrinsic growth rate, and N is the population size.

What is logistic population growth?

Population growth that occurs when resources are finite, leading to an S-shaped curve as the population approaches its carrying capacity.

What is carrying capacity (K)?

The maximum population size that a particular environment can sustain, which can vary in space and time.

What happens when population size (N) reaches carrying capacity (K)?

The population stops growing, entering a stationary phase.

What is the formula for logistic population growth?

dN/dt = rN(K-N)/K, where K is the carrying capacity.

What factors can change population density?

Immigration and births increase density, while emigration and deaths decrease it.

What is the change in population size equation?

Change in population size = births + immigrants - deaths - emigrants.

How do life history traits influence fitness?

Life history traits can affect the reproductive success and survival of individuals, impacting their lifetime fitness.

What is a trade-off in life history traits?

A situation where an increase in one trait (e.g., reproduction) may lead to a decrease in another trait (e.g., survival).

What is the significance of demographic parameters in population studies?

They help in understanding population structure, growth patterns, and the potential for future changes.

What is the role of biotic factors in population dynamics?

Biotic factors, such as competition and predation, can significantly influence population size and growth.

What is the role of abiotic factors in population dynamics?

Abiotic factors, such as climate and resources, can limit or enhance population growth and distribution.

What is the importance of studying population ecology?

It helps in understanding the interactions between species and their environments, which is crucial for conservation and management efforts.

What does the logistic model assume about populations?

It assumes populations can adjust instantaneously to density increases and that the environment remains constant.

Define life history in ecology.

Life history encompasses all traits that affect an organism's schedule of reproduction and survival.

List some examples of life history traits.

Mass at birth, age of sexual maturity, frequency of reproduction, reproductive lifespan, number of offspring, investment in parental care, senescence, age at death.

What is a life history trade-off?

A trade-off occurs when energy is allocated to different life history traits, affecting reproduction and survival.

What is r-selection?

r-selection favors traits that enhance reproductive success at low densities, leading to rapid maturation, early reproduction, and many offspring.

Describe characteristics of r-strategies.

R-strategies include rapid maturation, short lifespan, high offspring numbers, minimal parental care, and high mortality rates.

What is K-selection?

K-selection favors traits that enhance survival at high densities, focusing on fewer offspring with more parental investment.

Describe characteristics of K-strategies.

K-strategies include slow maturation, longer lifespan, fewer offspring, more reproductive events, and high offspring survival rates.

What ecological phenomenon do r and K strategies represent?

They represent two extremes of life history strategies found in ecological succession.

What is ecology?

Ecology is the study of how organisms interact with each other and their environment.

What factors influence ecological interactions?

Biotic factors (other organisms) and abiotic factors (physical and chemical properties of the environment).

What is a population in ecological terms?

A population is a group of individuals of the same species living in a specific area.

What is a community in ecology?

A community is a group of populations of different species in a given area.

Define ecosystem.

An ecosystem is a community of organisms interacting with the physical factors in their environment.

What is a landscape in ecological terms?

A landscape is a mosaic of connected ecosystems.

What is the biosphere?

The biosphere is the sum of all the planet's ecosystems and landscapes.

What is the significance of age-specific mortality in life history traits?

Age-specific mortality can better explain the evolution of life-history traits than density dependence alone.

What type of plant is likely to first establish after a volcanic eruption?

Lichens, mosses, and grasses, as they have r-strategies suited for rapid establishment in disturbed areas.

What are the implications of life history trade-offs?

Trade-offs can affect reproductive output and survival strategies, influencing population dynamics.

What is the relationship between egg size and fecundity in Drosophila melanogaster?

There are phenotypic negative correlations between egg size and fecundity in selected lines.

What does the logistic growth model describe?

It describes population growth as a function of the carrying capacity (K) and population size (N).

What is the formula for the logistic growth model?

The formula is dN/dt = rN(K-N)/K.