BIOL 228 Midterm Flashcards

Question

distribution and geographic range

Answer 1

distribution describes a populations spatial location and is based on the presence or absence of individuals geographic range is the area that encompasses all individuals of a species

Answer 2

the number of individuals in the population and defines its size is a function of population density

Answer 3

reflects the number of individuals per unit of available living space

Answer 4

Random - individuasl position is independent of others Uniform - results from negative interaction among individuals Clumped - results from patchy resources, social groupings, ramet dynamics

Answer 5

density x area

Answer 6

Based on trapping, marking and releasing a known # of marked animals (M) into the population (N), uses ratio of marked (R) to sampled (n) individuals

Answer 7

The movement of individuals in space, key process in metapopulation dynamics (maintains gene flow) Passive dispersal - like pollen n shit Emigration - individual moves out of the population Immigration - individual moves in to the population

Answer 8

animals that habitualy return to the same location, or stay in place

Answer 9

refers to how the numbers of individuals in a population increases or decreases with time Addition via births or immigration Subtracts via deaths and emigration immigration/ emigration only affects open populations

Answer 10

Rate of change of growth in a population best described by dN/dt = (b-d)N r= (b-d) = instantaneous growth rate exponential population growth = dN/dt = rN predicts the rate of population change through time r = per capita rate of increase also; Nsubt =Nnote^rt -- denotes population size at a given time under conditions of exponential growth

Answer 11

r = 0, no change in population size r > 0, population increases exponentially r < 0, population decreases exponentially Characteristic of populations that inhabit favourable conditions at low population densities

Answer 12

used to describe growth rates over discreet time intervals (distinct season on births) lambda= e^r or r = lnlambda

Answer 13

an age specific account of mortality

Answer 14

a group of individuals born in the same period of time

Answer 15

x = age classes nx = number of individuals from original cohorts alive at a specified age (x) lx = survivorship value, probability at birth of surviving to any given age (x) dx = the difference between the number of individuals alive for any age class (nx) and the next older class (nx+1) qx = age specified mortality rate, the number of individuals that died in a given time interval (dx)/(nx) ex = age specific life expectancy, the average number of years that an individual of a given age (nx) us expected to live into the future Lx = the average number of individuals alive during age interval x to x+1 Tx = total years lived into the future by individuals of age class x in the pop.

Answer 16

number of individuals from original cohorts alive at a specified age (x)

Answer 17

lx = survivorship value, probability at birth of surviving to any given age (x)

Answer 18

dx = the difference between the number of individuals alive for any age class (nx) and the next older class (nx+1)

Answer 19

qx = age specified mortality rate, the number of individuals that died in a given time interval (dx)/(nx)

Answer 20

ex = age specific life expectancy, the average number of years that an individual of a given age (nx) us expected to live into the future

Answer 21

Lx = the average number of individuals alive during age interval x to x+1

Answer 22

Tx = total years lived into the future by individuals of age class x in the pop.

Answer 23

Mortality curves plot qx against age x survivorship curves plot lx against age x Three kinds of survivorship curves Type 1 - populations with individuals with long lifespans, survival rate is high throughout with heavy mortality at the end (humans) Type 2- survival rates do not vary with age (birds, rodents, reptiles) Type 3 - mortality rates high early in life (fish, trees)

Answer 24

the study of population growth

Answer 25

mean number of females born to a female in each age group

Answer 26

average number of female offspring born to a female over her lifetime

Answer 27

combine survivorship (lx) with age specific birthrates (bx) lxbx = mean number of females born in each age group adjusted for survivorship R0 = net reproductive rate, average number of females that will be produced during a lifetime by a newborn female

Answer 28

net reproductive rate, average number of females that will be produced during a lifetime by a newborn female R0=1, females replace themselves in population R0 < 1, females are not replacing themselves in pop R0 > 1 females are more than replacing themselves

Answer 29

generation time - mean time between when female is born and when she reproduces for a single generation t = Tc results in being able to solve for r r ~ (ln(R0))/Tc

Answer 30

S shaped curve in which birth and death rates vary in density dependent manner deals with realistic environmental limitations in the real world, resources are limited and the environment is not constant, if the rate of consumption exceeds the rate at which resources are resupplied then resources will shrink

Answer 31

takes into account rates of births and deaths that vary with population size / accounts for carrying capacity dN/dt = rN (1- N/K) When N>K population growth is negative when N

Answer 32

influence a population in proportion to its size as pop density increases; the mortality rate increases fecundity rate decreases or both

Answer 33

The ability to produce new offspring; fertility

Answer 34

competition between members of the SAME species Exploitation competition occurs when individuals indirectly interact with one another but affect the availability of shared resources (e.g., herbivores on the African savannas) * Interference competition results when individuals directly interact and prevent others from occupying a habitat or accessing resources within it (e.g., bird species’ nesting sites)

Answer 35

Age specific survival rates represent the probability that a female of that age will survive to the next age class

Answer 36

Demographic stochasticity is the random (stochastic) variations in birth and death rates from year to year – The variations in d and b cause populations to deviate from the predictions based on deterministic models Environmental stochasticity is the random variations in the environment or the occurrence of natural disasters – These events directly influence d and b

Answer 37

Population fluctuations that are more regular than expected are called

Answer 38

local extinction small populations are at an increased risk of extripation due to many factors, unable to find a mate etc goes along with the Allee affect?

Answer 39

Is the decline in reproduction or survival under conditions of low population density * There is less genetic variation in a small population and this may affect the population’s ability to adapt to environmental change Small population size may result in the breakdown of social structures that are integral to successful cooperative behaviours (mating, foraging, defence)

Answer 40

relationship that affects the populations of two or more species adversely Exploitation competition occurs when species indirectly interact with one another but affect the availability of shared resources Interference competition results when species directly interact and prevent others from occupying a habitat or accessing resources within it

Answer 41

states that “complete competitors” cannot coexist – Complete competitors are two species that live in the same place and have exactly the same ecological requirements If population of complete competitor A increases the least bit faster than complete competitor population B, then A will eventually outcompete B (B will become extinct)

Answer 42

can be defined as a species response to the total of all abiotic and biotic factors in its environment Hutchinsons concept of the niche as an "n-dimensional hypervolume" Niche dimensions include resources and conditions a single habitat may support a number of niches some species may interact in some niche dimensions but not others limited by the fact that there could be limitless niche dimensions

Answer 43

full range of conditions and resources under which it can survive and reproduce

Answer 44

portion of the fundamental niche that the species actually exploits often regulated by competition, some species only use a portion of a habitat when grown in competition but would use all of it if grown alone

Answer 45

differences in the range of resources used or environmental tolerances bird on diff parts of tree example (resources partitioning)

Answer 46

involves a shift in feeding niche that subsequently affects a species morphology behaviour or physiology

Answer 47

The relationship between the per capita rate of consumption and the number of prey. relationship between the per capita predation rate (number of prey consumed per unit time) and prey population size * Its shape depends on several factors: – Predator time budgets related to chasing, killing, eating, and digesting prey – Predator search images and prey switching

Answer 48

An increased consumption of prey results in an increase in predator reproduction The ability of a predator population to regulate a prey population is related to the response of predators to increase in number in relation to prey – Predator populations grow slowly in comparison to those of their prey and dynamics lag that of prey

Answer 49

Type 1 - common with sessile organisms Type 2 - more common like wolf/ moose Type 3 - sigmoidal shape shows initial inefficiency There are several possible explanations for a sigmoidal type III response: – Availability of cover: the susceptibility of prey individuals will increase as the population grows and hiding places become filled – Search image: the ability of a predator to recognize a prey species will increase as the prey population size increases – Prey switching: the act of a predator turning to a more abundant alternate prey

Answer 50

species that are critical to maintaining biodiversity ie predators can allow the coexistence of competing prey when the stronger competitor is favoured by the predator prevents competitive exclusion

Answer 51

An interaction between two prey species, where the presence of one prey has a negative effect on the other, but not the other way around – E.g., when one species has a negative effect on another by bringing to it exposure to a pathogen or predator – Depends strongly on the effectiveness of the predator

Answer 52

Chemical defence is widespread – Alarm pheromones induce flight reactions in members of the same and related species – Odorous secretions repel predators – Storage or synthesis of toxins and poisons

Answer 53

Animals that are toxic to predators LOOK toxic

Answer 54

is the similar colour pattern shared by many unpalatable or venomous species – This is effective because the predator has tobe exposed to only one of the species before learning to stay away from all other species with the same warning colour patterns

Answer 55

occurs when an edible species mimics the inedible species (the model) – Butterflies and snakes – Mimicry is not limited to colour pattern (e.g., rattle-like sound)