Population properties

Question 1

Who is Thomas Malthus?

Answer 1

Malthesian Model in population growth.

Question 2

What is the REDLIST?

Answer 2

international coloboration of endangered species.
comes down to the population size and variance.

Question 3

African Penguin

Answer 3

Breeds in 28 places.
only the breeding sites on land masses (africa) are the protected ones.
Considered as a endangered Animals - why the decrease in he population?
egg and guano harvesting and food competition with humans.

Question 4

What is a population?

Answer 4

a group of potentially interbreeding individuals of the same species occupying a defined area.

Question 5

What are characteristics that result from being in aggregation of interacting individuals?

Answer 5

Structure - number, age distribution density, spacing
Dynamics - continuous changw ethrough time; births; deaths; maturation

in populations these variables can determine how “successful” it will be.

Question 6

What is a modular / clonar individual?

Answer 6

Individuals that have more than one copy.
- one tree can be a clone of another and is connected via roots.
dont take whatever info you are given at face value

Question 7

What is an unitary individual?

Answer 7

organism that has its own genes.

Question 8

What is population distribution?

Answer 8

The area that a population occupy’s. - not constant in time.

Question 9

What is a climate change sentinel?

Answer 9

population is changing due to climate change to some extent.

Question 10

How to calculate population abundance?

Answer 10

density x area = PA

Question 11

What are the different kinds of distribution?

Answer 11

• normal distribution
• clumped distribtution
• random distribution

arrangement and distribution is important to calculate the entire distribution of a population.

Question 12

What eeds to be considerd when trying to measure the distribution of a population?

Answer 12

Different considerations need to be taken into account:
- plot counts
- line transects
- belt transects

Question 13

What are some challenges with sampling density of a population?

Answer 13

crude density - density per total habitat area
ecological density - density per unit habitable area
relative density - not actual density but comparative.

Question 14

How can we deal with these challenges?

Answer 14

Removeal sampling:
Catch per unit effort - measure the catch per certain amount of time compare it later in time.

calculating a relative measure of what the population is doing over time.
fisheries.

Standardised sampling:

Mark-recapture methods:
N (estimate population size) =M(total # animals captured and marked first) C(total # animals captured on second mark) /R (# aniamls recaptured on 1 and 2 time)
problem = tag shedding and lack of mixing

Question 15

What is a population structure?

Answer 15

Largely controlled by mortality; natality; maturation.
Strong differences btw short & long-lived species.
Strong differences between populations with discreet non-overlapping generations and continuous or annual reproductive behaviour

Question 16

What is an age structure?

Answer 16

They are often depicted as age pyramids.
Developing have high ratios of young people to old people.
The ratios between young and old people are more equal in developed countries.

Question 17

Gender ratios

Question 18

Population dynamics are determined by?

Answer 18

Births added
Deaths subtracted
- just looking at births and deaths known as a closed population

Immigration - entering a population
Emigration - leaving a population
- An open population can move between groups.

Question 19

What are the population dynamic features?

Answer 19

Largely controlled by mortality, natality; maturation
Strong differences btw short & long-lived species
Strong differences between populations with discreet, non-overlapping generations and continuous or annual reproductive behavior.

Question 20

Calculations

Answer 20

N(t) = N(t-1) + births - deaths

Model of exponential growth:
dN/dt= rN

To calculate population size:
N(t) = N(0) e^rt

Question 21

What is the model of population growth?

Answer 21

The change in population size over time is equal to the rate of population growth multiplied by the population.

Question 22

Variance in a population data series.

Answer 22

process variation:
- Demographic: population growth rate
- environmental: temporal and saptial
- individual: phenotypic and genotypic variations.

Question 23

Deterministic growth model

Answer 23

r>0 population will persist
r<0 population will go extinct
r=0 population will remain at a stable size.

Question 24

Logistic growth model

Answer 24

The logistic (sigmoid) curve of population growth over time. The
carrying capacity (K) and MSY (= K/2) are indicated along with
phases of slow and fast population growth.

• Phase 1: population increases at an exponential rate.
• Phase 2: deceleration towards equilibrium.
• Phase 3: population asymptotes at carrying capacity.

All populations converge on the carrying capacity, the speed at which they approach K is related to growth rate (r)

The Logistic equation is a much more reasonable model than the exponential growth equation because we know that populations must have an upper limit to growth. there is not enough matter in the universe to support exponential populations forever.

Question 25

population overshoot

Answer 25

when there is longterm sustained degradation to an environment the carrying capacity starts to degrade.