Ecology Chapter 10

Question 1

game theory

Answer 1

branch of mathematical theory and equations to provide a reason for why people decide the things they do (completx systems)

Question 2

benefits of group living

Answer 2

defense against predators
increased foraging ability
access to grooming
easy to find a mate

Question 3

drawbacks of group living

Answer 3

increased susceptibility to diseases (bacteria&viruses)
sharing food (competition)
competition for mates

Question 4

group living as a way to deal with predator benefits

Answer 4

1. encounter dilution or ‘selfish herd’ hypothesis
2. many eyes hypothesis
3. predator confusion hypothesis (fish example)

Question 5

per capita

Answer 5

rate of describing per head, per person, per individual

Question 6

population dynamics: N

Answer 6

number of individuals in the population

Question 7

population dynamics: N(t)

Answer 7

number of individuals at any given time

Question 8

population dynamics: N(0)

Answer 8

number of individuals in the population at t=0 or point when observation first starts

Question 9

population dynamics formula in terms of elephant example

Answer 9

Nt+1=Nt=B-D

N= # of elephants
B= births
D= deaths
t= number of elephants today

Question 10

B=bNt

Answer 10

B= # of births
b= birth rate
N= # of species
t= time

Question 11

dN/dt= rN

Answer 11

r= instantaneous per capita rate of increase
N= population size

Question 12

what does n=0 or r=0 mean?

Answer 12

the population is stable

Question 13

what does r > 0 mean?

Answer 13

the population is growing

Question 14

what does r

Answer 14

the population is shrinking

Question 15

assumptions of the population dynamics model

Answer 15

1. all individuals contribute equally to population growth or decline
2. r is a constant - environment is unlimited

Question 16

Nt= No^ert

Answer 16

equation essentially the same equation as compound of interest

e is logarithum number on calculator

Question 17

Discrete model handles what?

Answer 17

geometric population growth

Question 18

Nt+1=Nt (lambda)

Answer 18

use this equation when solving for one time step

(lambda) is multiplier, population growth rate

Question 19

what does lambda have to be for a population to be stable? growing? declining?

Answer 19

stable - 1
growth > 1
decline

Question 20

Nt = (lambda)tNo

Answer 20

use this equation when calculating future time step (50 years)

Question 21

intraspecific

Answer 21

within a species - bunnies compete with other bunnies

Question 22

if resources become limiting when a population size increases… what occurs?

Answer 22

limited growth
density dependence
negative density dependence

Question 23

what is limited growth caused by

Answer 23

limited growth is caused by changes to birth

Question 24

density dependence

Answer 24

density dependence occurs when per capita population growth rate changes with population density

Question 25

negative density dependence

Answer 25

negative density dependence increases in death rate and/or decreases in birth rate as population density increases

Question 26

why does birth/death rate change with population density?

Answer 26

intraspecific competition