Chapter 3 - Evolution, Biology, and Population Ecology

Question 1

species

Answer 1

a population or group of populations of organisms were member share certain characteristics and can breed freely with one another and produce fertile offspring. different biologists may have different approaches to diagnosing a species boundaries

Question 2

population

Answer 2

a group of organisms of the same species that live in the same area. species are often composed of many species

Question 3

natural selection

Answer 3

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, thus altering the genetic population through time

Question 4

mutation

Answer 4

an accidental change in DNA that may range in magnitude from the deletion, substitution, or addition of a single nucleotide, to a change effecting entire sets of chromosomes. mutations provide the new material for evolutionary change

Question 5

adaptation (evolution)

Answer 5

the process by which traits that lead to increased reproduction success in a given environment evolve in a population through natural selection

Question 6

adaptation (climate change)

Answer 6

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

Question 7

adaptive trait

Answer 7

a trait that confers greater likelihood that an individual will reproduce. also called an adaptation

Question 8

convergent evolution

Answer 8

the evolutionary process by which unrelated species acquire similar characteristics/traits as they adapt to selective pressure from their similar enviroments

Question 9

speciation

Answer 9

a process by which new species are generated

Question 10

biodiversity (biological diversity)

Answer 10

the variety of life across all levels of biological organization, including the diversity of species, their genes, their populations, and their communities

Question 11

artificial selection

Answer 11

natural selection conducted under human direction

Question 12

phylogenetic tree

Answer 12

a tree like diagram that represents the history of divergence of species or other taxonomic groups of organisms

Question 13

extinction

Answer 13

the disappearance of an entire species from earth

Question 14

fossil records

Answer 14

the cumulated body of fossils worldwide, which paleontologists study to infer the history if past life on earth

Question 15

endemic

Answer 15

native or restricted to a certain region. an endemic species occur only in one place in the world

Question 16

mass extinction events

Answer 16

the extinction of a large percentage of the worlds species in a very short period of time, earth has been in 5 mass extinction events in the past half-billion years

Question 17

survivorship curve

Answer 17

a graph that shows the likely-hood of death for members of a population varies with age

Question 18

demographer

Answer 18

a social scientist who studies population size, density, distribution, age structure, sex ratio, and birth, death, immigration, and emigration rates within the human population

Question 19

immigration

Answer 19

the arrial of individuals from outside the population

Question 20

emigration

Answer 20

the departure of individuals from a population

Question 21

rate of natural increase

Answer 21

the rate of change in a population size resulting from birth and death rates alone

Question 22

population growth rate

Answer 22

the rate of change in a population size per unit time. counts death, birth, immigration, and emigration rates (is usually measured in time per year)

Question 23

limiting factor

Answer 23

a physical, chemical, or biological characteristic of the environment that restricts the population growth

Question 24

carrying capacity

Answer 24

the maximum population size that a given environment can substain

Question 25

logistic growth curve

Answer 25

a plot that shows the initial exponential growth of a population is slowed and finally brought to a stand still by limiting factors

Question 26

K-selected

Answer 26

term denoting a species with low biotic potential whose members produce a small number of offspring and take a long time to gestate and raise each of their young, but they invest heavily on the survival and growth of their few offspring

Question 27

density-independent factors

Answer 27

a limiting factor whose effects are the same no matter the population size

Question 28

density-dependent factors

Answer 28

a limiting factor whose effects on a population increase or decrease depending on the population density

Question 29

age structure (age distribution)

Answer 29

the relative number of organisms of each age within a population. age distribution can have a great effect on rates of population growth or decline and are often expressed as a ratio of age classes, consisting of organisms (1) not yet mature enough to reproduce (2) capable of reproduction (3) beyond reproduction years

Question 30

sex ratio

Answer 30

the proportion of males to females in population

Question 31

population size

Answer 31

the number of individual organisms present at a given time in an organisms population

Question 32

specialist

Answer 32

a species that can survive only in a narrow range of habitats that contain very specific recources

Question 33

generalist

Answer 33

a species that can survive in a wide variety of habitats or use a wide array of recources

Question 34

niche

Answer 34

the functional role of a species in a community

Question 35

habitat selection

Answer 35

the process by which organisms select habitats from among the range of optionsencountered

Question 36

habitat

Answer 36

the specific environment in which an organism lives, including both biotic and abiotic factors

Question 37

ecology

Answer 37

the science that deals with distribution and abundance of organisms, the interactions between them and their abiotic environment

Question 38

biosphere

Answer 38

the sum total of all the planets organisms and the abiotic environment with which they inetact

Question 39

population ecology

Answer 39

the study of the quantitative dynamics of population change and the functions that affect the distribution and abundance of members of a population

Question 40

community

Answer 40

an assemblage of populations of organisms that live in the same place at the same time

Question 41

community ecology

Answer 41

the scientific study of the patterns of species diversity and interactions among species, from one to one interactions to complex inter-relationships involving entire communities

Question 42

ecotourism

Answer 42

visitation of natural area fro tourism and recreation. most often involves tourism by more affluent people, which may offer economic benefits for less affluent communities near natural areas and thus provide economic incentives for conservation of natural areas