Part 6: Struggle For Existence

Question 1

Most important differences among individuals are

Answer 1

sex and age

Question 2

Age structures model deal with sex in simpler way, how?

Answer 2

keep track of females only, ignore males

Question 3

Why do age structures ignore males?

Answer 3

Females = only able to reduce, they only propulsive force for population maintenance

Question 4

Poplation growth rates and generation times, acceptable to see males

Answer 4

as numerically inconsequential collective source fo sperm (not in short supply)

Question 5

Sex ratios close to 1;1, do math on females and just multiple by 2 = estimate total population of both sexes. T or F

Answer 5

T

Question 6

Population size steady if average female =

Answer 6

1 daughter in lifetime

Question 7

Assign individuals in population to classes based other age using x (subscript) for age

Answer 7

T

Question 8

Time span of an age class interval?

Answer 8

we want enough age classes to capture birth snd death aspects vary through females life

Question 9

Life tables for humans, age class how long?

Answer 9

5 yrs long each = 20 classes enough for human lifespan

Question 10

1st age class denoted by _
N=? 
N0=?
N1=?
N2=?
sum up nx values over all ages (x) =?

Answer 10

1st age class denoted by 0
N=Total population 
N0=newborns 
N1= 1years old
N2=2 year old
sum up nx values over all ages (x) = TOTAL POPULATION SIZE

Question 11

Capital stigma indicates

Answer 11

sum up following variables over all possible age classes

Question 12

What is age structure of population looking at

Answer 12

set of nx values (n0,n1,n2,n3,n4)

Question 13

Age pyramid

Answer 13

horizontal bar graph (represent age structure)

Question 14

Survivorship scheduled lx

Answer 14

age-specific risks of mortality

Question 15

lx = survivorship at age x =?

Answer 15

probability that an individual is still alive at age x

Question 16

Lx values are probabilities =

Answer 16

range from 0 to 1

Question 17

Lo=1, what does this mean?

Answer 17

Newborns are alive at birth

Question 18

Lx values must ALWAYS ____________ as x increase, the probability of being alive always declines with age

Answer 18

Decrease

Question 19

Lx values must decrease as x increases, why?

Answer 19

The probability of being alive always declines with age (eventually everyone dies)

Question 20

For life table to be useful, include what of enough?

Answer 20

enough age classes for the last Lx value to be zero

Question 21

Shape of survivor ship schedule, graph, what is comparing

Answer 21

(graph of Lx vs. x)

Question 22

species produce huge tiny offspring but they have few defences anise environmental stresses, graph look like

Answer 22

survivorship curve initial drops steeply (little ones Mosley die early, few survive = grow large enough to survive life and survivorship evens off)

Question 23

Species produce few offsprings but have resources invested in them = larger offspring, survivorship graph look?

Answer 23

larger offspring have resources and resiliency to handle environmental stresses = graph initially defends more gradually

Question 24

Senescene

Answer 24

die off from generalized breakdown of old organism, not environmental stresses

Question 25

Exponential Decline

Answer 25

CONSTANT HALF LIFE probability of dying I constant across all ages - external accidents rather from intrinsic biological characteristics (mortality or senescence) - Radioactive decay of unstable isotopes or expected lifespan of wineglasses in restaurant

Question 26

Type II survivorship (graph of Lx vs. x)

Answer 26

curves declines steeply but gradually approaches zero as an asymptote (r<0)

Question 27

Type II decline

Answer 27

log of survivorship (loglx vs. x = straight line with -ve slope)

Question 28

types of lines Type I=? Type II= ? Type III=?

Answer 28

1) convex curves (low early mortality) 2) Straight lines 3) Concave curves (much early death)

Question 29

bx= | not probabilities = ?

Answer 29

average number of daughters produced by females in her xth year not probabilities = exceed 1.0

Question 30

b0 = 0 (babies can't give birth)

Answer 30

``` unless age class intervals to be inappropriately wide (newborn need pass through period of resource acquit ion and growth after broth before they give birth themselves) ```

Question 31

Age of first reproduction

Answer 31

total # of offspring produce & waiting period before reproduction can begin

Question 32

Why do these model lack density dependance?

Answer 32

fecundity and survivorship secludes as constants

Question 33

Calcite population wide rates of increase, consider how __________ and __________ interact with each other

Answer 33

fecundity and survivorship

Question 34

Life time output of average female, discount her potential reproduction at a particular age by likelihood that she dies before reaching that age, formula?

Answer 34

1) (bxa)(its lxa) = answer a (bxb)(lxb) = answer b (bxc)(lxc) = answer c (for all age classes x) 2) answer 1 +answer2 + answer3 = expected number of daughters a female produce in her lifetime (net reproductive rate)

Question 35

net reproductive rate

Answer 35

expected # of daughters a female will produce in her lifetime

Question 36

net reproductive rate (Ro)=∑lxbx | Ro= act similarity to finite rate increase λ

Answer 36

expected # of daughters a female will produce in her lifetime

Question 37

Ro=1

Answer 37

each females exactly replaces herself and population size remain content

Question 38

Ro>1

Answer 38

population increase geometrically without limit

Question 39

Ro<1

Answer 39

population slides toward extinction

Question 40

How Ro and λ differ is in time scale which they measure?

Answer 40

``` Ro= amount of growth occurs over one generation λ = amount of growth occurs over one unit of time ```

Question 41

If you know number of females on each class at starting t = assumptions?

Answer 41

- fecundity and survivorship values fixed -all deaths and births occur during a time interval take place at last possible instant before next interval begins (several mothers host enter a time interval = all survive to end of interval (one second before midnight on last night of year for ex) all babies according to bx schedule some mothers die at midnight accorindgt o lx -surviving mothers ad no one gave class older -babies all small age (x=0) POPULATION GROW OR SHRINK as a step function

Question 42

Evolutionary ecology considers

Answer 42

the ecological circumstances that drive selection for such life shots characteristic (lifespan, age of first reproduction and number and timing fo offspring)

Question 43

Size-number tradeoff

Answer 43

allocation of limited resources (plant with fixes amount fo energy and nutrients) (production of offspring)

Question 44

Early vs late reproduction

Answer 44

newborn organisms undergo pre-reproductive period of growth and resource acquisition before they can birth their own. Early production = favoured by natural selection (individuals organisms that produce offspring earlier = will dominate population )

Question 45

Early vs late reproduction (Proviso - all else being equal)

Answer 45

organism that reduce earlier = do not have as long a period to get resources = candy male as many offspring as those who what longer to start

Question 46

Cost of reproduction

Answer 46

offspring take energy and nutrients that adult could use for other purposes (extend their own life span or saving to make other offspring in future)

Question 47

Cost of reproduction (higher animals) 1) parental survival can be reduced 2) parental resources for reproduction can be depleted (offspring production is delayed and diminish) HIGH bx early in life = reduces bx late in life

Answer 47

cost of reproduction extend beyond brith, they give parental care to kids (lactation = need material resources)

Question 48

R. A Fisher introduced

Answer 48

reproductive value as another aspect of life history (function of survivorship and fecundity schedules)

Question 49

Reproductive value Vx defined as

Answer 49

expected umber of daughters to be produced by a female of age x, now (xth) and for the rest of her life

Question 50

Any offspring produced before age x is irrelevant to Vx

Answer 50

reproductive value only looks forward in time

Question 51

Graph of Vx vs x gives humped shape

Answer 51

reaching was somewhere between youth and old age ( reductive value decline later in life)

Question 52

(humped graph of Vx vs. x). We know reproductive value declines later in life, why should a newborn with allure life ahead of her, have a lower future value than older female with only part of her life left?

Answer 52

Newborn must get through pre-reproductive, resource acquisition phase before she can reproduce and encounter risk of dying at that time period (vx of newborn lower than females successfully passed through early life risks)

Question 53

Relative reproductive

Answer 53

Vx/Vo

Question 54

Relative reproductive of newborn

Answer 54

1.0

Question 55

lasting pair bonds between mates

Answer 55

- fairly strong selection for males to refer females with high reproductive values - tendency for treats associated with consent reductive age to become associated with sexual attractiveness

Question 56

High Vx values (juveniles driven out of natal territories by dispute with parents)

Answer 56

individuals would have best chance of establishing successful new colony where males more likely to be the lines that disperse

Question 57

Semelparity (animals)

Answer 57

plants and animals, some species are genetically programs to reproduce once in their lifetimes and die

Question 58

iteroparity (animals)

Answer 58

plants and animals, some species are genetically programs to reproduce once in their lifetimes and die

Question 59

Iteroparous (plants) usually called perennials

Answer 59

genetically programs to reproduce once in their lifetimes and die

Question 60

Semelparous (plants) get names depending on how long they live

Answer 60

genetically programs to reproduce once in their lifetimes and die

Question 61

Semelparous (plants) get names depending on how long they live but all called monocarpic (making fruit once)

Answer 61

genetically programs to reproduce once in their lifetimes and die - 1 season live = annuals

Question 62

Biennials

Answer 62

programmes to grow vegetatively for one year and the flower and die in 2nd year (stressful condition, take some extra years fo growth to get enough resources to flower)

Question 63

Monocarpic perennials

Answer 63

live longer than 2 years before flowering and then die

Question 64

Dormancy

Answer 64

small, fast maturing plant that compresses all its active growth into the brief wet season and produce seeds that spend the dry season

Question 65

Weeds

Answer 65

annuals are prominent (adapted for growing in transient habitats that been disturbed by natural phenomena (animal burrowing) or human activities (agriculture) -

Question 66

Fugitive Species

Answer 66

solid disturbance allows a brief period for small annual plants to occur an ungrounded bare site before pushed out by taller perennials (better competitors) - Fugitive species: KEEP DISCOVERING new bare patches

Question 67

Desert and weedy annuals adapted to take advantage of brief windows of time, rapid growth possible by milder conditions

Answer 67

- large proportion of population under soil and have long lasting seed banks in soil Desert: these seeds on germinates only after heavy rains have leached out the inhibitors, plants start growth when water available Weedy: germinated only when stuck by sunlight (get started right after soil disturbance that brings them to surface - most remain in seed bank)

Question 68

Crop plants 1) RIce 2) Maize 3) Wheat

Answer 68

perennials | AI through human to max seed output and allow regular cultivation of soil

Question 69

how long lived semelparous perennially can be an advantageous statergy?

Answer 69

Animal pollinators so such ants may hav been disproportionally striated to visit the plants with largest inflorescences (display) = could confer reproductive advantages on plants that waited longer to flower = store up more resources = produce showier displays

Question 70

how long lived semelparous perennially can be an advantageous statergy?

Answer 70

Animal pollinators of such plants may have been disproportionally attracted to visit the plants with largest inflorescences (display) = could confer reproductive advantages on plants that waited longer to flower = store up more resources = produce showier displays