Chapter 14: Population Ecology Flashcards Preview

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Flashcards in Chapter 14: Population Ecology Deck (37)
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1
Q

Ecology

A

The study of the interactions between organisms and their environments

2
Q

Individuals

A

Individual organisms

3
Q

Populations

A

Groups of individual organisms that interbreed with each other

4
Q

Communities

A

Populations of different species that interact with each other within a location

5
Q

Ecosystems

A

All living organisms as well as non living elements that interact in a particular area

6
Q

Population Ecology

A

A sub field of ecology that focuses on populations of organisms of a species and how they interact with the environment

7
Q

Growth Rate

A

The change in the number of individuals in the population in some unit of time

8
Q

Calculating Growth Rate

A

The growth of the population in a year is the growth rate times the number of individuals present to start with

9
Q

r

A

Birth rate minus the death rate

10
Q

N

A

Number of individuals in the population now

11
Q

Exponential Growth

A

The bigger the population the faster it grows

12
Q

As population increases

A

Food supplies are reduced, less places to live, increased disease, and increased predation risk

13
Q

Population Density

A

The number of individuals in a given area

14
Q

Density Dependent Factors

A

Any factor limiting the size of a population whose effect is dependent on the number of individuals in the population. Ex. Disease

15
Q

Carrying Capacity

A

The ceiling of growth. Death rate increases, emigration rate increases, and usually a reduction in birth rate, reduction in fertility

16
Q

Slowing Down Exponential Population Growth

A

(r x N) x [(K - N)/K].

17
Q

Logistic Growth

A

When a population grows exponentially at first but then slows down as the population size approaches the carrying capacity

18
Q

Density Independent Factors

A

Forces like floods, earthquakes, and fires that disrupt growth. Takes time before Growth goes back to logistic Growth

19
Q

Maximum Sustainable Yield

A

The size of a natural population at which it produces a maximum rate of increase, usually about half of the carrying capacity

20
Q

Life History

A

Tells us as much about a species as possible in a small amount of information. Includes vital statistics, age at first reproduction, litter size, frequency, and longevity

21
Q

Reproductive Investment

A

All of the material and energetic contribution that an individual will make to its offspring

22
Q

Big Bang Reproduction

A

Reaches sexual maturity at one year, mates intensely over a 3 week period, males die shortly after mating period, and females usually die after weaning their first litter

23
Q

Fast, Intensive Reproductive Investment

A

Reaches sexual maturity at one month and produces litters of six to ten offspring every month

24
Q

Slow, Gradual Reproductive Investment

A

Reaches sexual maturity at one year and produces about one offspring per year

25
Q

What is the cost of the reproductive Investment during any reproductive episode?

A

Chance of predation and the wear and tear of reproduction on an individuals body takes its toll. Smaller litters are usually preferred because of the possibility of additional litters

26
Q

What is an individuals likelihood of surviving to have future reproductive episodes?

A

Small organisms like mice need to produce multiple offspring per litter while humans only need to produce one offspring per litter

27
Q

Tradeoffs: Reproduction and Survival

A

In Big Bang reproducers investment in reproduction is high. If individuals are physically prevented from reproducing they can live many more years

28
Q

Tradeoffs: Reproduction and Growth

A

Growth can sometimes be stunted when organisms spend time reproducing

29
Q

Tradeoffs: Number and Size of Offspring

A

Some lizards can lay more eggs if they are smaller but a higher proportion of the offspring survive if the eggs are larger

30
Q

Life Table

A

Tallies the number of people in a population within a certain age and the number of individuals within that age range that die

31
Q

Survivorship Curves

A

Graphs showing the proportion of individuals of a particular age that are now alive in a population

32
Q

Type I Survivorship Curve

A

High survivorship until old age, then rapidly decreasing survivorship

33
Q

Type II Survivorship Curve

A

Survivorship decreases at a steady pace

34
Q

Type III Survivorship Curve

A

High mortality early in life but those that survive the early years live long lives

35
Q

Aging

A

Emerges as a definitive and measurable feature. It is an increased risk of dying with increasing age after reaching the age of maturity

36
Q

Hazard Factor

A

Includes the risk of death from all types of external forces

37
Q

Demographic Transition

A

Refers to the transition from high birth and death rates to lower birth and death rates as a country develops into an industrialized economic system