Chapter 3: Evolution, Biodiversity, and Population Ecology EVR 1001

According to the graph the percent transmission of UV-B relative to light intensity at the water's surface:

Decreases with increasing depth.

Which of the following is accurate?

Ecotourism combines wildlife conservation with economic benefits.

Darwin, Charles (1809-1882)

English naturalist who proposed the concept of natural selection as a mechanism for evolution and as a way to explain the great variety of living things. Compare Wallace, Alfred Russel.

evolution

Genetically based change in populations of organisms across generations. Changes in genes may lead to changes in the appearance, physiology, and/or behavior of organisms across generations, often by the process of natural selection.

Which of the following events could NOT be caused by a population bottleneck?

Increased population size

What prediction(s) can researchers make based on the egg-viability hypothesis? Select all that apply.

-The probability of hatching failure will be higher in large clutches. -The probability of hatching failure will be higher later in the spring season. -The probability of hatching failure will be lower at higher latitudes.

Which of the following statements are true of a population at carrying capacity? Select all that apply.

-The rate at which resources are used is equal to the rate at which they are supplied. -The population growth rate equals zero. -The birth rate equals the death rate.

Which of the following statements are true of logistic growth? Select all that apply.

-When the population reaches carrying capacity, it stops growing. -As the population approaches carrying capacity, it grows more slowly.

If the UV-B radiation at the surface has an intensity of 0.27 watts/m2, approximately what is the intensity at a depth of 100 cm?

0.07 watts/m2

Assume there are 200 MendAliens living on an island in my back yard. If my island has an area of 20 hectares, what is the population density of MendAliens in terms of MendAliens per hectare?

10 MendAliens per hectare

Which water depth had the biggest difference in survival rates for embryos with UV-B protection versus embryos without UV-B protection?

10 cm

You are doing a mark-recapture experiment to determine the population size of the MendAliens living on an island in my back yard. Initially, you catch and mark 130 MendAliens, which you then release. Next, you capture 90 MendAliens, of which 20 are marked. What is your estimate of the population size of MendAliens living on the island in my back yard?

585

population

A group of organisms of the same species that live in the same area. Species are often composed of multiple populations.

Which statement below most accurately describes a phylogenetic tree?

A phylogenetic tree is a branching diagram used to illustrate a scientist's hypothesis about how divergence took place among evolutionary lines.

limiting factor

A physical, chemical, or biological characteristic of the environment that restrains population growth.

species

A population or group of populations of a particular type of organism whose members share certain characteristics and can breed freely with one another and produce fertile offspring. Biologists may differ in their approaches to diagnosing species boundaries.

ecologist

A scientist who studies ecology.

demographer

A social scientist who studies the population size; density; distribution; age structure; sex ratio; and rates of birth, death, immigration, and emigration of human populations. See demography.

generalist

A species that can survive across a wide array of habitats or can use a wide array of resources. Compare specialist.

specialist

A species that can survive only in a narrow range of habitats or that depends on very specific resources. Compare generalist.

phylogenetic tree

A treelike diagram that represents the history of divergence of species or other taxonomic groups of organisms.

mutation

An accidental change in DNA that may range in magnitude from the deletion, substitution, or addition of a single nucleotide to a change affecting entire sets of chromosomes. Mutations provide the raw material for evolutionary change.

Which of the following statements best describes the relationship between UV-B transmission and embryo survival rates shown on the graph?

At shallow depths UV-B transmission is high and unprotected embryo survival rates are low.

change in population

Brown beetles survive to reproduce more than green beetles do. The brown allele increases in frequency.

Wallace, Alfred Russel (1823-1913)

English naturalist who proposed, independently of Charles Darwin, the concept of natural selection as a mechanism for evolution and as a way to explain the great variety of living things.

ecosystem

In ecology, an assemblage of all organisms and nonliving entities that occur and interact in a particular area at the same time.

community

In ecology, an assemblage of populations of interacting organisms that live in the same area at the same time.

Which of the following statements about the amoeba population described at the end of the tutorial is true?

It is more vulnerable to extinction due to lack of genetic variation.

Consider the effects of several drier-than-average years on the western toad population. If the average depth of pools available for toad spawning declines, what other effects might be associated with the drier climate?

Lower than average embryo survival rates.

artificial selection

Natural selection conducted under human direction. Examples include the selective breeding of crop plants, pets, and livestock.

endemic

Restricted to a particular geographic region. An endemic species occurs in one area and nowhere else on Earth.

Use the figure above to answer the following question.Which of the following can be inferred from the figure?

The ancestors of snakes had legs.

background extinction rate

The average rate of extinction that occurred before the appearance of humans. For example, the fossil record indicates that for both birds and mammals, one species in the world typically became extinct every 500-1000 years. Compare mass extinction event.

density-independent

The condition of a limiting factor whose effects on a population are constant regardless of population density.

density-dependent

The condition of a limiting factor whose effects on a population increase or decrease depending on the population density.

fossil record

The cumulative body of fossils worldwide, which paleontologists study to infer the history of past life on Earth.

extinction

The disappearance of an entire species from Earth. Compare extirpation.

convergent evolution

The evolutionary process by which very unrelated species acquire similar traits as they adapt to similar selective pressures from similar environments.

mass extinction event

The extinction of a large proportion of the world's species in a very short time period due to some extreme and rapid change or catastrophic event. Earth has seen five mass extinction events in the past half-billion years.

niche

The functional role of a species in a community.

exponential growth

The increase of a population (or of anything) by a fixed percentage each year. Results in a J-shaped curve on a graph. Compare logistic growth.

carrying capacity

The maximum population size of a given organism that a given environment can sustain.

population size

The number of individual organisms present at a given time in a population.

population density

The number of individuals within a population per unit area. Compare population size.

logistic growth

The pattern of population growth that results as a population at first grows exponentially and then is slowed and finally brought to a standstill at carrying capacity by limiting factors. Results in an S-shaped curve on a graph. Compare exponential growth.

speciation

The process by which new species are generated. In one common mechanism, allopatric speciation, species form in the aftermath of the physical separation of populations over some geographic distance.

habitat selection

The process by which organisms select habitats from among the range of options they encounter.

habitat use

The process by which organisms use habitats from among the range of options they encounter.

natural selection

The process by which traits that enhance survival and reproduction are passed on more frequently to future generations of organisms than traits that do not, thereby altering the genetic makeup of populations through time. Natural selection acts on genetic variation and is a primary driver of evolution.

sex ratio

The proportion of males to females in a population.

adaptation (re: climate change)

The pursuit of strategies to protect ourselves from the impacts of climate change.

population growth rate

The rate of change in a population's size per unit time (generally expressed in percent per year), taking into accounts births, deaths, immigration, and emigration. Compare rate of natural increase.

rate of natural increase

The rate of change in a population's size resulting from birth and death rates alone, excluding migration. Compare population growth rate.

age structure

The relative numbers of individuals of different ages within a population. Age structure can have a strong effect on rates of population growth or decline and is often expressed as a ratio of age classes, consisting of organisms (1) not yet mature enough to reproduce, (2) capable of reproduction, and (3) beyond their reproductive years.

fossil

The remains, impression, or trace of an animal or plant of past geologic ages that has been preserved in rock or sediments.

ecology

The science that deals with the distribution and abundance of organisms, the interactions among them, and the interactions between organisms and their nonliving environments.

ecosystem ecology

The scientific study of how the living and nonliving components of ecosystems interact.

community ecology

The scientific study of patterns of species diversity and interactions among species, ranging from one-to-one interactions to complex interrelationships involving entire communities.

population ecology

The scientific study of the quantitative dynamics of population change and the factors that affect the distribution and abundance of members of a population.

population distribution

The spatial distribution of organisms in an area. Three common patterns are random, uniform, and clumped.

habitat

The specific environment in which an organism lives, including both biotic (living) and abiotic (nonliving) elements.

lanscape ecology

The study of how landscape structure affects the abundance, distribution, and interaction of organisms. This approach to the study of organisms and their environments at the landscape scale focuses on broad geographic areas that include multiple ecosystems.

biosphere

The sum total of all the planet's living organisms and the nonliving portions of the environment with which they interact.

biodiversity

The variety of life across all levels of biological organization, including the diversity of species, genes, populations, and communities. The term is short for biological diversity.

If a population has an annual growth rate of 10%, what would its population size be in two years?

There is not enough information given to answer this question.

ecotourism

Visitation of natural areas for tourism and recreation. Most often involves tourism by more-affluent people, which may generate economic benefits for less-affluent communities near natural areas and thereby provide economic incentives for conservation of natural areas.

environmental change

a drought causes habitat to turn dry and brown

A coyote, which can alter its food intake to match seasonal abundance of plants, fruits, or small animals, is considered to be ________.

a generalist

Which of the following would best represent a clumped population dispersion pattern?

a pod of 40 migrating gray whales in the Bering Sea

If a population had a carrying capacity of 1000 individuals, which of the following populations would be experiencing the greatest rate of growth as a percentage of the current population size?

a population of 10 individuals

Use the figure above to answer the following question.In the initial fruit fly population at the top of the figure, it is safe to assume that ________.

any male in the population could successfully mate with any female

For two organisms to belong to the same species, individuals of their species must __________.

be able to reproduce and have fertile offspring

According to the figure, crocodiles are most closely related to ________.

birds

Which of the following factors does not contribute to environmental resistance?

birth rate

Of the following, ________ are the major factors that determine a population's growth rate.

birth rate, death rate, emigration, and immigration

One example of artificial selection is ________.

broccoli, cauliflower, cabbage, and brussels sprouts bred from Brassica oleracea

__________ is the scientific study of the interactions among organisms and of the relationships between organisms and their environments.

ecology

A single, small population that exists only in one place on the planet is considered __________ to that area.

endemic

The passenger pigeon is __________.

extinct

The two processes that determine the world's current biodiversity are ________.

extinction and speciation rates

True or False. In the example described in the tutorial, the red amoebas survived the catastrophic event, and all future generations of amoebas were red because the red amoebas had a higher reproductive rate than the blue ones.

false

selective pressure

green beetles are more visible to birds than brown beetles, so birds eat more green beetles.

A __________ is defined as the living and nonliving elements in the area around an organism.

habitat

At Hakalau Forest in ________, ranchland is being restored to forest, invasive plants are being removed, native plants are being planted, and néné are being protected while new populations of them are being established.

hawaii

As a population approaches carrying capacity, environmental resistance __________.

increases

Members of two separate species cannot __________.

interbreed

The invasive European buckthorn invades a local forest preserve. Initially, the population of buckthorn rapidly increases, and then it begins to level off. This pattern of population growth most closely resembles ________.

logistic growth

A species' ________ is its functional role in its community.

niche

Which of the following would be a limiting factor for a population of dolphins in the ocean?

numbers of fish that dolphin prey on

Read the following scenario and answer the question(s) below.In 1906, President Theodore Roosevelt created the Grand Canyon National Game Preserve on the Kaibab Plateau in northern Arizona. Between 1907 and 1923, cattle grazing was greatly reduced, mule deer hunting was eliminated, and predators were killed. Over 800 cougars, 20 wolves (most had already been killed in the 1800s), and 7000 coyotes were trapped or shot. In response, the mule deer herd began to increase: By 1915, deer numbers were estimated at 25,000; 50,000 by 1920; and 100,000 by 1923.The initial population of Kaibab deer in 1906 was about 4000. In an area of about 800,000 acres, this works out to an average density of one deer per 200 acres. What was the density in 1923?

one deer per 8 acres

The __________ of a population is the proportion of males to females in the population.

sex ratio

The mark-recapture method would be best for sampling a population of _____.

sharks

Population distribution describes ________.

spatial arrangement of individuals of a single species within a particular area or ecosystem

The niche of a species is the functional role of that species in the community that it belongs to. Species that have narrow niches (have very specific resource requirements) are said to be ________, while species that have broad niches (able to use a wide array of resources) are known as ________.

specialists; generalists

Extinction is ________.

the disappearance of a species from Earth

Heavy rains and mudslides cause a river to change course, isolating two groups of lizards of the same species from one another. Over a long period of time ________.

the groups will probably diverge genetically, and speciation may occur

You are an ecologist researching divergent evolution on the Galapagos Islands. Which of the following might you be studying?

the processes by which the various species of finches on the islands diverged from a common ancestor

A small group of leaf-feeding beetles locates a field of snap beans, one of the preferred plants for this species. At first, the population grows rapidly in the snap bean field, but as the beetle population grows larger, predators, such as spiders and birds, discover the beetles and start to remove individuals from the population. Competition for mates, food, and oviposition (egg-laying) sites intensifies for the individuals in the beetle population as population density increases. A fungal disease also starts to kill many of the beetles. The population no longer grows rapidly but levels off. How many of these factors controlling the beetle population are density-independent factors?

zero