Unit 4 Flashcards

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1
Q

Sea Otter Case Study

A
  • Live in giant kelp forests on Pacific coast
  • Hunted almost to extinction by early 1900s
  • Partial recovery since listed as endangered in 1977

Reasons to care about sea otters:
- Keystone species
- Ethics
- Tourism dollars

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2
Q

Five Types of Species interactions

A
  • Competition
  • Predation
  • Parasitism
  • Mutualism
  • Commensalism
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3
Q

Competition

A
  • Most common interaction is competition

Interspecific competition
- Competition between different species to use the same limited resources

Resource partitioning
- Occurs when different species evolve specialized traits that allow them to share the same resources
- Species may use only parts of resource
- At different times
In different ways

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4
Q

Interspecific competition

A
  • Competition between different species to use the same limited resources
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5
Q

Resource partitioning

A
  • Occurs when different species evolve specialized traits that allow them to share the same resources
  • Species may use only parts of resource
  • At different times
    In different ways
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6
Q

Predation

A
  • Predator feeds directly on all or part of a member of another species (prey)
  • Strong effect on population sizes and other factors in ecosystems
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7
Q

Methods of Predation

A
  • Walk, swim, or fly
  • Camouflage
  • Chemical warfare
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8
Q

Ways that prey avoid predators

A
  • Camouflage
  • Chemical warfare
  • Warning coloration
  • Mimicry
  • Behavioral strategies
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9
Q

Coevolution

A
  • Changes in the gene pool of one species can cause changes in the gene pool of the other
  • Example: bats and moths
  • Echolocation of bats and sensitive hearing of moths
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10
Q

Predation + Natural Selection

A

Animals with better defenses against predation tend to leave more offspring

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11
Q

Parasitism

A
  • One species (parasite) lives on another organism
  • Parasites harm but rarely kill the host
  • Examples: tapeworms, sea lampreys, fleas, and ticks
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12
Q

Mutualism

A
  • Interaction that benefits both species
  • Nutrition and protective relationship
  • Not cooperation—mutual exploitation
  • Example: clownfish live within sea anemones
  • Gain protection and feed on waste matter left by anemones’ meals
    Clownfish protect anemones from some predators and parasites
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13
Q

Commensalism

A
  • Benefits one species and has little effect on the other
  • Examples:
  • Epiphytes (air plants) attach themselves to trees
  • Birds nest in trees
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14
Q

Ecological succession

A
  • Normally gradual change in structure and species composition in a given system
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15
Q

Primary ecological succession

A
  • Involves gradual establishment of communities in lifeless areas
  • Need to build up fertile soil or aquatic sediments to support plant community
  • Pioneer species such as lichens or mosses
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16
Q

Secondary ecological succession

A
  • Series of terrestrial communities or ecosystems develop in places with soil or sediment
  • Examples: abandoned farmland, burned or cut forests, and flooded land
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17
Q

Factors affecting secondary ecological succession rate

A

Facilitation of area by one species for another
Inhibition hinders growth

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18
Q

Intertia

A

Ability of a living system to survive moderate disturbances

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19
Q

Resilience

A

Ability of a living system to be restored through secondary succession after a moderate disturbance

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20
Q

Population

A

Group of interbreeding individuals of the same species

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21
Q

Population size

A
  • May increase, decrease, or remain the same in response to changing environmental conditions
  • Scientists use sampling techniques to estimate

Variables that govern changes in population size:
- Births, deaths, immigration, and emigration

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22
Q

Population distribution

A
  • Most populations live together in clumps or groups
  • Organisms cluster for resources
  • Protection from predators
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23
Q

Age structure

A
  • Distribution of individuals among various age groups
  • Pre-reproductive, reproductive, and post-reproductive stages
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24
Q

Quadrant Sampling

A

can be used to determine abundance, density, and distribution of species

25
Q

Mark and Recapture Sampling

A

used to estimate the size of an animal population in a defined area

26
Q

Lincoln Index

A

mathematical formula to estimate the size of animal populations.

27
Q

Range of Tolerance

A

Variation in physical and chemical environment under which it can survive

28
Q

Limiting Factors

A
  • Terrestrial ecosystems - Precipitation, temperature, insolation, soil type
  • Aquatic Ecosystems - Water temperature, depth, clarity, salinity, dissolved oxygen
  • Population density
  • Density-dependent factors
29
Q

J - Curves (r)

A
  • Some species can reproduce exponentially (r)
  • Produces J-shaped curve of growth if there are no limiting factors
  • Reproduce at an early age
  • Have many offspring each time they reproduce
  • Short intervals in between reproductive cycles
    Examples: bacteria and many insect species
30
Q

Environmental Resistance

A

Sum of all factors that limit population growth

31
Q

Carrying Capacity

A
  • Maximum population of a given species that a particular habitat can sustain indefinitely
  • Overshoot results in population crash
32
Q

r-Selected Species

A
  • Species with capacity for a high rate of population growth
  • Produce many offspring at one time
  • Do not care for their offspring
  • May go through irregular and unstable cycles in population sizes
  • Examples: algae, bacteria, frogs, most insects, and many fish
  • have J-curves
33
Q
A
34
Q

k-Selected Species

A
  • Species that reproduce later in life
  • Have few offspring
  • Tend to care or nurture offspring
  • Have long life spans
  • Can be vulnerable to extinction
    -Examples: large mammals, whales, humans, birds of prey, and long-lived plants
  • Have k-curves
35
Q

Survivorship Curves

A
  • Shows the percentages of members of population surviving at different ages
  • Late loss (K-selected species) (TYPE ONE)
  • Early loss (r-selected species) (TYPE THREE)
  • Constant loss (many songbirds) (TYPE TWO)
36
Q

Factors impacting rapid rise of human population

A
  • Emergence of agriculture increased food production
  • Technologies help humans expand into almost all the planet’s climates and habitats
  • Drop in death rates with improved sanitation and health care
37
Q

Top three countries in terms of population

A

China - 1,425,671,352 people
India - 1,425,775,850 people
USA - 339,996,563 people

38
Q

Rate of human population growth

A
  • Rate of population growth has slowed since 1960 to 1.1% (If this continues, the world’s population will double in 64 years)
  • World’s population is still growing
39
Q

Human population geographically

A

Human population growth is unevenly distributed geographically
2% added to more-developed countries
98% added to less-developed countries

40
Q

Cultural Carrying Capacity

A

Maximum number of people who could live in reasonable freedom and comfort indefinitely, without decreasing the ability of the earth to sustain future generations

41
Q

Population change (equation)

A

(Births + Immigration) – (Deaths + Emigration)

42
Q

Crude birth rate

A

Number of live births per 1,000 people in a population per year

43
Q

Crude death rate

A

Number of deaths per 1,000 people in a population per year

44
Q

Total fertility rate

A

Average number of children born to women in a population

45
Q

Replacement-level fertility rate

A
  • Average number of children a couple must bear to replace themselves
  • Approximately 2.1
  • Higher than 2 because some children die before reaching reproductive years
46
Q

Total Fertility Rate (TFR)

A
  • Average number of children born to women of childbearing age in a population
  • Between 1955 and 2012, the global TFR dropped from 5 to 2.5
  • To eventually halt population growth, the global TFR must drop to the fertility replacement level of 2.1
47
Q

Case Study - The US Population - Third Largest and Growing

A
  • Population is still growing
  • 76 million in 1900
  • 322 million in 2015
  • 339 million in 2023 (GROWTH RATE OF .21%)
  • Drop in TFR in the U.S.
  • Rate of population growth has slowed
  • 40% of total U.S. population increase in 2015 came from legal immigration
  • China surpassed Mexico as largest source of new immigrants
48
Q

Factors that affect BIRTH and fertility rates

A
  • Importance of children as part of the labor force
  • Especially in less-developed countries
  • Cost of raising and educating children
  • Availability of pension systems
  • Urbanization
  • Educational and employment opportunities for women
  • Average age at marriage
  • Availability of reliable birth control methods
  • Religious beliefs, traditions, and cultural norms
49
Q

Factors that affect DEATH rates

A
  • Indicators of overall health of people in a country
  • Life expectancy
  • Infant mortality rate
  • Number of babies out of every 1,000 who die before their first birthday
  • Factors that cause high infant mortality
  • Insufficient food, poor nutrition, and infectious disease
50
Q

Migration

A
  • The movement of people into and out of specific geographic areas
      • – Reasons for migration
  • Jobs and economic improvement
  • Religious persecution or ethnic conflict
  • Political oppression or war
  • Environmental refugees - (potato famine, global warming - it can be a Tool in war)
51
Q

Aging Populations can Decline Rapidly

A
  • Slow decline is generally manageable
  • Rapid decline leads to economic problems
  • Proportionally fewer young people working
  • Labor shortages
  • Some countries with rapidly declining populations
    Japan, Germany, Italy, Bulgaria, Hungary, Romania, Cuba, and Portugal
52
Q

How can we slow human population growth?

A
  • Controversy on whether population growth needs to slow
  • Ways to slow human population growth
  • Reducing poverty through economic development
  • Elevating the status of women
  • Encouraging family planning
53
Q
  1. Economic Development (Slowing human population growth)
A
  • —–Demographic transition
  • As countries become industrialized, poverty declines
  • Populations then tend to grow more slowly
  • ——Threats to making a demographic transition
  • Extreme poverty and war
  • Environmental degradation and resource depletion
54
Q
  1. Educating and Empowering Women (Slowing human population growth)
A

Women have fewer children if:
- Educated
- Able to earn an income
- Society does not suppress their rights

55
Q
  1. Family Planning (Slowing human population growth)
A
  • Family planning benefits
  • Reduced unintended pregnancies, births, and abortions
  • Better maternal and child health care
    Reduced rate of infant mortality
  • Financial benefits
    Problems
  • Lack of access to voluntary contraception
  • Child marriage customs
56
Q

Case Study - Population Growth in India

A

Population of 1.31 billion in 2015
- (1.425 billion 2023 + 115 million in 7 years)
growth rate 2020 = .96%, 2022 = .81%
Problems
- Poverty, malnutrition, and environmental degradation
Causes
- Most poor couples want many children
- Bias toward having male children
- Only 47% of couples use modern birth control methods

57
Q

Big Ideas

A
  • The human population is growing rapidly
  • May soon bump up against environmental limits
  • Combination of population growth and increasing rate of resource use per person is expanding human ecological footprint
  • Strains the earth’s natural capital
  • We can slow human population growth by reducing poverty, elevating the status of women, and encouraging family planning
58
Q

Case Study - Slowing population growth in China

A
  • World’s 2nd most populous country
  • Threat of mass starvation in the 1960s
  • Government established strict family planning and birth control program in 1978
  • Reduced number of children born per woman from 3 to 1.7
  • TFR was already declining before 1978 due to increased education and employment opportunities for women
  • Negative effects of one-child policy
  • Preference for male children resulted in skewed population: too few females
  • Average population age increasing at one of the fastest rates ever recorded
  • By 2030, likely too few young workers to support aging population
  • 2015: Chinese government replaced one-child policy with two-child policy. If you were an only child, you can have 2 children.