Chapter 9

Question 1

What is population growth, and what is it controlled by?

Answer 1

• number of individuals in a population increasing or decreasing over time
  
  • controlled by rate of new individuals added through birth and immigration, and removed through death and emigration

Question 2

What is an open population?

Answer 2

populations in which immigration or emigration occurs

Question 3

What is a closed population?

Answer 3

those with movement into and out does not occur

Question 4

What is the equation for population size at a given time?

Answer 4

population at the start of the experiemnt + birth - death

Question 5

What is the equation for per capita birthrate?

Answer 5

birth/ population size at a given time

Question 6

what is geometric population growth?

Answer 6

population size as a function of time

population change * population size

Question 7

What is exponential population growth?

Answer 7

instantaneous per capita rate of growth

Question 8

what is a life table?

Answer 8

age specific account of mortality

tracks them over a period of time, tracking how much has died

Question 9

What is a cohort?

Answer 9

group of individuals born in the same period

Question 10

What is survivorship?

Answer 10

probability at birth of surviving at any given age (fx)

Question 11

What is dx in a lifetable>

Answer 11

difference between number of individuals alive for any age class (nx) and the next older age class (number that dies)

Question 12

What is age-specific mortality rate?

Answer 12

(qx)- the number of individuals that died during a given time/ number alive at the beginning of the interval

Question 13

What is a dynamic life table?

Answer 13

uses cohorts to determine fate of a group of individuals

Question 14

What is dynamic composite life table?

Answer 14

cohort from individuals born over several time periods instead of just one

Question 15

What is a time-specific life table?

Answer 15

samples population in some manner to obtain a distribution of age classes during a single time period

Question 16

What does time-specific life table assume?

Answer 16

assumes age class was sampled in proportion to its numbers in the populations

Question 17

How are life tables of insects and single breeding seasons tracked?

Answer 17

stages of life is tracked

Question 18

What is studied in plant life tables? (3)

Answer 18

• seedling mortality and survival
• population dynamics of perennial plants marked as seedlings
• life cycles of annual plants

Question 19

What is a type 1 survivorship, and what is it seen in?

Answer 19

• when population survives, survival rate is high through life span follwoed by heavy mortality at the end (type 1)
  
  • humans, mammals, and some plants

Question 20

WHat is type 2 survivorship curve, and what animals exhibits it?

Answer 20

• if survival rates do not vary with age, it can be straight (type 2)
  
  • adult birds, rodents, reptiles, and perennial plants

Question 21

What is type 3 survivorship, and what animals have it?

Answer 21

• early mortality (type 3)
  
  • oysters, fish, invertebrates, and trees

Question 22

What is crude birthrate?

Answer 22

dividing number of births in a period of time by estimated population size by the time period

Question 23

What is age-specific birthrate?

Answer 23

function following mean number of females born to a female in each age group

Question 24

What is gros reproductive rate?

Answer 24

average number of female offspring produced

Question 25

What is facundity table?

Answer 25

uses survivorship column and age-specific birthrates

Question 26

What is net reproductive rate? (3)

Answer 26

- average number of females that are produced during a lifetime by a newborn female - at 1, females will replace themselves (produce one daughter) - if 0, females do not replace themselves

Question 27

What is population projection table?

Answer 27

ollows a given female population at birth

Question 28

What factor other than age can be used to describe life stages?

Answer 28

size

Question 29

What is age distribution?

Answer 29

proportion of individuals in the various age classes for any on year

Question 30

What is a stable age distribution?

Answer 30

- population attains an unchanging number - proportion of each age group stays the same even if population is increasing

Question 31

What is a finite multiplication rate?

Answer 31

- total number of individuals in year t+1/ total number of individuals in the previous year - greater than 1 means growing - equal 1 is stable

Question 32

What is demographic stochasticity?

Answer 32

- random variations in birth and death rates from year to year - causes population deviation from prediction

Question 33

What is environmental stochasticity?

Answer 33

random variations in the environment that influences birth and death rates

Question 34

What factors can lead to population extinction? (4)

Answer 34

- small populations are more susceptible to extinction - extreme environmental events can increase mortality - shortage of supply or overexploitation - invasive species