LECTURE 4 - LIFE CYCLES AND POPULATION

Question 1

Population

Answer 1

A group of individuals in from one species

->boundries determined geographically or purposely for simplification

Question 2

What drives population change?

Answer 2

Birth, death, migration, immigration and emigration

Question 3

Individuals

Answer 3

Unitary individual -> have a set predictable look and development (ex// us)
Modular -> Have set parts or modules that will develop, but not perfectly predictable (ex// a tree)

Question 4

How can you tell a modular individual?

Answer 4

Check the RENET (off branches that could look like a different individual ) if its GENET (genetically the same)

Question 5

How to calculate a population?

Answer 5

Capture, recapture method
marked/total pop = recap. marked/ total recap.
if random density, count a sub-area then multiply by total area

Question 6

Iteroparous Species

Answer 6

breeds repeatedly ex// humans

Question 7

semelparous species

Answer 7

expends all energy into a single reproductive moment ex// some flowering plants

Question 8

Seed banks

Answer 8

After plant releases their seeds, they form a seed bank. Often these do not begin to grow till conditions are favourable (avoider species)

Question 9

Anual life cycles

Answer 9

One full generation per year, from birth to death ex//trillium

Question 10

perennial life cycles

Answer 10

individuals have generations that cross over each other

-> life cycle lasts a while

Question 11

biennial life cycles

Answer 11

takes two years to go through an entire life cycle

ex// Salmon with their long reproductive cycle

Question 12

cohort life table

Answer 12

Looks at the survivorship and fecundity of a cohort as they grow from birth to death

Question 13

Static life table

Answer 13

looks at individuals at different ages to determined fecundity and survivorship

Question 14

Survival rate

Answer 14

Determines if the population will inc or dec

• > Ro > 1, pop inc
• > Ro < 1, pop dec
• > Ro = 1, rate of basic growth (just replaces itself)

Question 15

measure the survival rate?

Answer 15

E lx * Mx(reproduction of individuals) = Ro

lx (survival of individuals)= ax/total pop

Question 16

Types of survivorship curves

Answer 16

type 1 -> Mortality inc as the individual gets older
ex//humans
type 2 -> morality constant throughout live ex// birds
type 3 -> morality highest at birth ex//plants

Question 17

Dispersal patterns

Answer 17

can be random, regular (uniformed) or argrigated (in groups)

Question 18

Calculate density

Answer 18

total pop/ total area of habitat

Question 19

What determines abuncance?

Answer 19

If density high then resources decrease (& vice versa)

Then it’s determined by intraspecific competition

Question 20

The carrying capacity (k)

Answer 20

determined when the birth and death rates become equal

-> max population that can be supported by their recourses

Question 21

Types of population growth

Answer 21

rate of natural inc (r) -> shows exponential growth (tends to dec as k is approached)
Logistic growth (k) -> shows an s curve as it chills by carrying capacity

Question 22

r vs k species

Answer 22

r -> Reproduce fast with many offsprings. Good for changing env. lives in the “r” phase
k -> few large offsprings. intense competition for resources. Likes in the “k” phase

Question 23

Cohort

Answer 23

Individuals in a population born in a certain period