Comprehensive Biology and Ecology: Evolution, Biodiversity, and Biomes

Chapters 3 and 4

What is natural selection?

Natural selection is a process that favors certain inherited characteristics over others, leading to those traits being passed on more frequently in a population.

How does evolution influence biodiversity?

Evolution leads to the diversification of species, resulting in a variety of life forms and ecological interactions, which contributes to overall biodiversity.

What are the causes of species extinctions?

Species extinctions can be caused by habitat destruction, climate change, invasive species, overexploitation, and significant mass extinction events.

What are the levels of ecological organization?

The levels of ecological organization include individual, population, community, ecosystem, biome, and biosphere.

How can you predict the growth of a population?

Population growth can be predicted by examining factors such as birth rates, death rates, immigration, emigration, and the carrying capacity of the environment.

What factors influence population ecology?

Factors influencing population ecology include resource availability, predation, disease, competition, and environmental conditions.

What are the challenges in biodiversity conservation?

Challenges in biodiversity conservation include habitat loss, climate change, pollution, invasive species, and limited funding for conservation efforts.

What is a species?

A species is a classification of organisms whose members can interbreed and produce fertile offspring.

What is a population?

A population is a group of individuals of the same species that live in the same geographic area.

What is evolution?

Evolution is the process by which populations change over generations as genetic changes alter their physical and behavioral characteristics.

What is adaptation?

Adaptation is the process by which traits that enhance reproductive success become more common in a population over time.

Who proposed the concept of natural selection?

The concept of natural selection was first proposed by Charles Darwin and Alfred Russel Wallace in the 1850s.

What are mutations?

Mutations are accidental changes in DNA that create genetic variation among individuals.

What is convergent evolution?

Convergent evolution occurs when unrelated species independently evolve similar traits due to similar selective pressures in their environments.

What is artificial selection?

Artificial selection is the process by which humans selectively breed organisms for desired traits.

What is speciation?

Speciation is the process by which new species are generated, often through mechanisms like allopatric speciation.

What is allopatric speciation?

Allopatric speciation occurs when populations become physically separated by geographic barriers, leading to the evolution of distinct species.

What is a phylogenetic tree?

A phylogenetic tree is a diagram that represents the evolutionary relationships among various species based on genetic and morphological data.

What is a fossil?

A fossil is an imprint in stone of a dead organism, providing evidence of past life forms.

What is extinction?

Extinction occurs when a species no longer exists, often due to rapid environmental changes that exceed the species' ability to adapt.

What makes species vulnerable to extinction?

Species that are small, specialized, endemic to a region, or isolated on islands are especially vulnerable to extinction.

What is background extinction rate?

The background extinction rate is the normal rate of extinction of species due to natural processes, occurring gradually over time.

What are mass extinction events?

Mass extinction events are periods in Earth's history when a significant percentage of species were wiped out in a relatively short time, often due to catastrophic events.

What was the Permian extinction?

The most catastrophic mass extinction event that occurred 250 million years ago, leading to the loss of a significant percentage of Earth's species.

What are some causes of mass extinction?

Volcanism, asteroid impacts, methane releases, and global warming.

What is the current extinction rate compared to the background rate?

The current extinction rate is 100-1000 times higher than the background extinction rate.

What are some human activities contributing to extinction?

Altering or destroying habitats, overhunting, pollution, introducing non-native species, and climate change.

What is ecology?

The study of interactions among organisms and between organisms and their environments.

What is a population in ecology?

A group of individuals of the same species that live in the same area.

What is a community in ecology?

All the populations of different species that live and interact within a specific area.

What is an ecosystem?

A community of living organisms and their interactions with the abiotic (nonliving) parts of their environment.

What is the biosphere?

The sum total of all living things and habitats on Earth.

What is habitat selection?

The process by which mobile organisms choose where to live based on their habitat needs.

What is a niche?

An organism's role in its community, including resource use and interactions with other organisms.

What are specialists in ecology?

Species that have narrow niches and specialize in specific resources.

What are generalists in ecology?

Species that can utilize a wide variety of resources and have broader niches.

What is population density?

The number of individuals per unit area within a population.

What is population distribution?

The spatial arrangement of organisms within an area, which can be random, uniform, or clumped.

What is sex ratio?

The proportion of males to females in a population.

What is age structure in a population?

The distribution of individuals of different ages within a population, which helps predict future growth or decline.

What is natality?

The birth rate within a population.

What is mortality?

The death rate within a population.

What is immigration in population ecology?

The arrival of individuals from outside the population.

What is emigration in population ecology?

The departure of individuals from the population.

What is exponential growth?

When a population increases by a fixed percentage each year, resulting in a J-shaped growth curve.

What is carrying capacity?

The maximum population size of a species that an environment can sustain.

What is logistic growth?

Population growth that slows as it approaches carrying capacity, resulting in an S-shaped curve.

What are density-dependent factors?

Factors that rise and fall with population density, such as predation and disease.

What are density-independent factors?

Factors that are unaffected by population density, such as temperature extremes and catastrophic natural disasters.

How can carrying capacities change?

Carrying capacities can change due to environmental factors like forest fires or human activities that alter the environment.

What does life history theory explain?

It explains how natural selection influences reproduction, survival, and lifespan in species.

What are r-selected species?

Species that produce many offspring but provide little or no parental care, often thriving in unpredictable environments.

What are K-selected species?

Species that have few offspring but invest heavily in their survival, typically found in stable environments.

What is the impact of human development on biodiversity?

Human development and resource extraction accelerate environmental changes that can displace or harm native species.

What is ecotourism?

A form of tourism that focuses on visiting natural areas, which can provide economic benefits while promoting conservation.

How does climate change affect ecosystems?

Climate change alters temperature and rainfall patterns, which can impact even protected areas and their species.

What is competition in ecology?

A relationship where organisms seek the same resource, which can be intraspecific (same species) or interspecific (different species).

What is competitive exclusion?

A principle stating that if one species is a stronger competitor, it may exclude other species from a resource.

What is species coexistence?

A situation where multiple species live side by side without one excluding the others, often leading to niche differentiation.

What is a fundamental niche?

The full potential niche of a species, including all the resources it could use without competition.

What is a realized niche?

The actual niche that a species occupies, which may be smaller due to competition or other interactions.

What is resource partitioning?

A process where individuals of different species use shared resources in different ways to minimize competition.

What is predation?

The process by which predators capture, kill, and consume prey, affecting population dynamics.

How does predation affect population dynamics?

An increase in prey can lead to an increase in predators, and vice versa, influencing the populations of both.

What adaptations do predators develop?

Predators may develop adaptations that enhance their hunting abilities, favored by natural selection.

What types of defenses do prey evolve?

Prey evolve various defenses to reduce the risk of predation, driven by natural selection.

What is parasitism?

A relationship where one organism depends on another for nourishment, usually without causing the host's death.

What are parasites?

Organisms that live on or in a host and obtain nourishment at the host's expense.

What are pathogens?

Parasites that cause disease, which can include protists, bacteria, or viruses.

What is coevolution?

The process by which parasites and hosts adapt and counter-adapt to each other.

What is herbivory?

A relationship where animals feed on the tissues of plants.

What are some defenses plants have against herbivores?

Toxic chemicals, thorns, spines, or irritating hairs.

What is mutualism?

A relationship where two or more species benefit from each other.

What is symbiosis?

A close physical association between species, often involving mutualistic relationships.

What are trophic levels?

Ranks within the feeding hierarchy of a community, indicating who eats whom.

What are producers?

Organisms that use photosynthesis or chemosynthesis to make their own sugars.

What are primary consumers?

Organisms that consume producers.

What are secondary consumers?

Organisms that prey on primary consumers.

What are tertiary consumers?

Organisms that prey on secondary consumers.

What are decomposers?

Organisms that break down nonliving matter into smaller molecules that recycle nutrients back into the soil.

What is biomass?

The collective mass of living matter in a given place and time.

What is a keystone species?

A species that has an impact far greater than its abundance, influencing the structure of the ecosystem.

What is a trophic cascade?

An ecological phenomenon triggered by the removal of a top predator, leading to overconsumption of producers by primary consumers.

What is a disturbance in ecology?

Any event that has rapid and drastic effects on a community and ecosystem.

What is resistance in ecological communities?

The ability of a community to resist change and remain stable despite disturbances.

What is resilience in ecological communities?

The ability of a community to change due to a disturbance but return to its original state.

What is primary succession?

The process of ecological change that occurs when a disturbance removes all plant or soil life.

What is secondary succession?

The process of ecological change that occurs when a disturbance alters a community but leaves the soil life intact.

What is a regime shift?

A significant change in the character of a community due to disturbances such as climate change or the loss of a keystone species.

What is the role of microbes in the human digestive tract?

They provide a place to live and help digest food, representing a mutualistic relationship.

What is intraspecific competition?

Competition between individuals of the same species for resources.

What is food web?

A complex network of feeding relationships within an ecological community, showing how energy flows between organisms.

What are introduced species?

Introduced species are non-native arrivals in a community brought by people.

What are invasive species?

Invasive species are introduced species that thrive and establish populations, often outcompeting native species.

What is ecological restoration?

Ecological restoration is the process of restoring altered areas to their condition before industrialized civilization.

What are no-analog communities?

No-analog communities are mixtures of species that have not previously occurred together on Earth, often due to human disturbance.

What is the purpose of eradication in managing invasive species?

Eradication aims for the total elimination of an invasive population, though it is often difficult and expensive.

What is a biome?

A biome is a regional complex of similar communities, classified primarily by dominant plant type and vegetation structure.

What factors most influence climate?

Temperature and precipitation exert the greatest influence over all other climatic factors.

How does climate affect biomes?

Climate, including temperature and precipitation, determines the types of biomes found in a region.