Life History & Demography

Question 1

positive effects of asexual reproduciton

Answer 1

• higher fitness
• rapid population growth

Question 2

negative effects of asexual reproduction

Answer 2

• low genetic variability
• no way to get rid of bad genes

Question 3

porfolio effect

Answer 3

genetic diversity allows orgaisms to respond better to environmental conditions

Question 4

hermaphroditic

Answer 4

organisms have male and female organs

Question 5

life history

Answer 5

sequence of organim’s life events; way that they allocate resources for growth and survival

Question 6

life history trade-off

Answer 6

between survival and fecundity

Question 7

life history trait

Answer 7

heritable trait that determines an aspect of organism’s life history and can change with conditions (e.g. number of offspring, lifespan)

Question 8

life history strategy

Answer 8

pattern of traits that evolved by natural selection

Question 9

high fedundity-low survivorship

Answer 9

• reach sexual maturity earlier
• produce many eggs/seeds

Question 10

high survivorship-low fecundity

Answer 10

• grows slowly
• traits that protect from predators

Question 11

demography

Answer 11

study of factors that determine population size and structure

Question 12

4 factors affecting demography

Answer 12

• birth
• death
• immigration
• emigration

Question 13

life table

Answer 13

a table that includes:
- age
- number of individuals
- fecundity
- survivory ship
- number of offspring/female born (survivorship x fecundity)

Question 14

survivorship

Answer 14

proportion of individuals remaining from one age class to the next

Question 15

types of surivorship curves

Answer 15

type 1: high survivorship when young, low when old
type 2: steady
type 3: low survivorship when young, high when old

Question 16

fecundity

Answer 16

number of female offsping produced

Question 17

R0

Answer 17

the growth rate of a population per generation, stable if R0=1

Question 18

survivorship curve of albertosaurus

Answer 18

predicted to be: type 3
actual: type 1

Question 19

per-capita popualtion growrth rate (r)

Answer 19

r = b-d
- difference between birth rate and death rate
- if r = 0, steady growrth rate

Question 20

How to calculate r based on R0?

Answer 20

r = ln(R0) / G

Question 21

population growth equation

Answer 21

Nt = N0^(r x t)

Question 22

maximum intrinsic growth rate (r max)

Answer 22

• when birth rates peak and death rates are as low as possible
• does not change for a species

Question 23

exponential population growth

Answer 23

population growth = r (N)
- r remains constant
- growth is not based on population size
- can occur for new population or bottleneck
- does not consider competition

Question 24

logistric population growth

Answer 24

population grorwth = (r) (K-N/K) (N)
- r declines
- growth is based on (declining) population size
- K = carrying capacity

Question 25

density dependent

Answer 25

- based on growing/shrinking population size - factors are biotic (food, predators)

Question 26

density independent

Answer 26

- based on a constant population size/growth - factors are abiotic (weather, natural disaster)

Question 27

antagonistic selection

Answer 27

when components of fitness oppose each other (e.g. sexual vs. fecundity)

Question 28

principle of allocation

Answer 28

enegry used for one function will reduce the enegry available for another

Question 29

semelparous

Answer 29

individuals generate multiple offspring, providing little parental care; increases fitness of parent but decreases fitness of young

Question 30

iteroparous

Answer 30

individuals produce less offspring with more parental care; increases fitness of young but decreases parent fitness

Question 31

metapopulations

Answer 31

populaitions that are linked by immigration/emigration

Question 32

ecological footprint

Answer 32

land and water area needed to sustain a population

Question 33

extinct

Answer 33

all members of species are not found anymore

Question 34

extinct in the wild

Answer 34

only living members of species are in captivity

Question 35

locally extinct

Answer 35

members of species are no longer found in a specific area

Question 36

ecologically extinct

Answer 36

members are reduced that it no longer has an effect on its community

Question 37

overkill hypothesis

Answer 37

human hunting resulted in the megafaunal excitntion

Question 38

background exctinction

Answer 38

the cause of most exctinctions

Question 39

ecosystem services

Answer 39

processes where natural ecosystems benefit humans (air purification, nutrient cycles)

Question 40

3 major causes of endangered spp

Answer 40

habitat loss, pollution, overexploitation

Question 41

Which mass excintion are we currently in?

Answer 41

6th, human induced