Lecture 8: Unregulated Population Growth

Question 1

r-selected
time to maturation
relative #offspring
parental care
lifespan
#reproductive events
offspring survivorship

Answer 1

short
many
little or none
short
many
low

Question 2

k-selected
time to maturation
relative #offspring
parental care
lifespan
#reproductive events
offspring survivorship

Answer 2

long
few
lots
long
few
high

Question 3

size versus number tradeoffs between dandelion and coconut palms

Answer 3

dandelions have lots of smalls seeds, coconut palm has few large seeds

Question 4

semelparity

Answer 4

organisms that only reproduce once

Question 5

iteroparity

Answer 5

species that reproduce multiple times ( most plants )

Question 6

under what conditions would you expect long living organisms to be semelparous

Answer 6

environments with less resources needed for reproduction and where optimal conditions for offspring survival is infrequent.

Question 7

Unregulated populationg rowth can be considered under two groups which are

Answer 7

geometric population growth, and exponential population growth

Question 8

geometric population growth

Answer 8

population grow in discrete time intervals, populations reproduce synchronously

discreme geometric growth example: 1, 2, 4, 8, 16, 32, 64…

Question 9

exponential population growth

Answer 9

populations grow continuously, generations overlap (humans grow continuously)

Question 10

rdeltaD

Answer 10

the contribution that an average member of the population makes to the population size during the time interval deltat (per capita change in population size)

Question 11

What drives change in the size of the entire population

Answer 11

deltaN/deltat = Births-Deaths
(deltaN=population size, deltat=time interval)

aka deltaN/deltat=R

Question 12

What is R in the equation deltaN/deltat=R

Answer 12

the difference between the number of births and number of deaths that occur in the time interval which is the NET REPRODUCTIVE RATE

Question 13

how do we calculate change in population size over time

Answer 13

deltaN/deltat=R and R= rdeltatN

Question 14

what is the change in population size with exponential growth written as?

Answer 14

deltaN/deltat=rdeltatN

Question 15

how do we calculate change in population size over time with geometric growth

Answer 15

Nt+1 = lambdaNt
Nt=population size after t generations
Nt+1= population size after t+1 generations
lambda= geometric growth rate of increase

Question 16

When lambda < 1 or r < 0

Answer 16

the popuplation size decreases

Question 17

when lambda > 0 or r > 0

Answer 17

the population increases in size

Question 18

when lambda = 1 or r=0

Answer 18

the population size does not change

Question 19

is the r constant for exponentially growing populations?

Answer 19

yes, the r value is constnt and unaffected for exponentially growing populations

Question 20

little r is used for

Answer 20

populations undergoing exponential growth increasing at an instant at a time