Sponge: Set up Cornell Notes on pg. 19

Topic: G5 Population Ecology

Essential Question: Describe the major differences between r-strategists and K-strategists. Include examples.

BIOZONE: 232-236 due Thurs

G5 Population Ecology

BIOZONE: 232-236

Describe the major differences between r-strategists and K-strategists. Include examples.

Key Vocabulary:r-strategyK-strategy

Which of these two organisms is most likely to survive an ecological disaster which caused extreme changes in both terrestrial (land) and aquatic ecosystems?

Zebra Mussel Zebra

Which of these two organisms is most likely to survive an ecological disaster which caused extreme changes in both terrestrial (land) and aquatic ecosystems?

Zebra Mussel Zebra

• In order to answer this question properly, we need to understand some background information about the animals in question:

• With your table, make a list (whiteboards- 2 per table) of everything you know about the habitat (environment), reproduction (offspring #/parenting styles/reproduction rate), growth rate, food habits, life span, size…. of the zebra mussel or zebra (feel free to use internet on phone)

P. 18

Zebra Mussel Zebra

• Live 4-5 years• Unstable environment• Lays thousands of eggs which

hatch into free swimming larvae• Most of the eggs will die (eaten)• Hundreds will survive • No parental care• In the event of an ecological

disaster: A few would be likely to survive

• Known as r-strategy

• Live up to 40 years• Requires a stable environment • Long gestation period (pregnancy)

during which the mother needs good nutrition

• Baby zebra need maternal care• Savannah must have enough food• In the event of an ecological disaster:

The few offspring produced would NOT survive

•Known as K-strategy

Assessment Statement

• G.5.1 Distinguish between r-strategies and K-strategies

r-strategist (rate) K-strategist (K=carrying capacity)P. 19

• Organisms that live in stable environments tend to make few, "expensive" offspring.

• K-selected species— species whose population sizes fluctuate at or near their carrying capacity (K)

• Organisms that live in unstable environments tend to make many, "cheap" offspring

• r-selected species, also called r-strategist, species whose populations are governed by their biotic potential (maximum reproductive capacity, r, or rate)

K-strategists

r-strategists

Assessment Statement• G.5.2 Discuss environmental conditions that favor either r-strategies

or K-strategies

• Use whiteboards to brainstorm:• Life span:• Size:• Reproduction rate: • Offspring #s:• Parental care:• Growth rate:• Type of environment they live in:• Includes examples of animals

r- Strategy• “disposable offspring”• Mostly insects• Life span short• Many offspring- most are

lost• Early maturity-grow quickly• Small body size• Usually only reproduce once

during lifetime• No parental care• Unstable environments

K- Strategy• Nurturing• Larger animals- almost all

mammals• Long life span• Few offspring• Later maturity-grow slowly• Large body size• Produce offspring more than

once during life span• Parental care likely• Stable environment

Ecological Disruption:

• Favors r-Strategists!!!!!• If you call something a “pest”, its likely an r-strategist• It is adapted to become established quickly before its competitors get

a foothold • In a balance ecosystem, the r-strategists have interactions with other

species that control their numbers (they get eaten)

Sponge: Set up Cornell Notes on pg. 21

Topic: The Population Explosion

Essential Question: None.

BIOZONE: 232-236 due Thurs

The Population Explosion

BIOZONE: 232-236

The Population Explosion

Overpopulation• It took the ENTIRE history of humankind for the population to reach 1

billion in 1810• Just 120 years later, it was 2 billion (1930)• 4 billion (1975)• 7.2 billion (2014)

• 9.7 billion (2050)?

Current and Projected World Population by 2050

North America- United States

Africa- Congo

The World

The Causes….• Until recently, birth and death rates were equal• People had a lot of children, but many of them died before the age of 5-6

• During the Industrial Revolution:• Increases in food production/distribution• Improvement in public health (water/sanitation)• Medical technology (vaccines/antibiotics)

The Consequences…• Population grows fastest in the world’s poorest countries• High poverty usually equals high fertility and high infant mortality• But infant mortality rates are dropping due to improved standards of living• That leaves a huge % of the world’s population as young people in child bearing

years

• Which means we need to…• Meet food/water needs• Health care/education• Try and control poverty levels

Any real advances in well being are negated by further population growth!

Population Reference Bureau (3m35s)• https://www.youtube.com/watch?v=d1dIAtvSFLM

Solutions….

Table Discussion: 2014 Population Reference Bureau

1. Current country with top population?2. Projected 2050 country with top population?3. What is the average children, per female, in a Nigerian family?4. What country is having the least amount of children per family?5. Why might less developed countries have a higher birth rate than more developed countries?6. What is the World percentage of infant deaths per year vs. births per year? (death#/birth# x 100)7. What is the difference in percentage of infant deaths in less developed countries to more developed countries? (find % for more and less developed then subtract)8. Worldwide how many infants die per minute?9. How many people worldwide live on less that $1.25 a day? Where?10. Take a look at the world population pyramids. What might explain Africa’s almost perfect pyramid shape vs. Europe’s “bush” shaped pyramid?11. What might explain the drastic difference in maternal mortality in undeveloped countries vs. developed countries?

Homework/Classwork• Please read “The Population Explosion: Causes and Consequences”• Highlight important details

Sponge: Set up Cornell Notes on pg. 23

• Topic: Population Decline Case Study: Why Have all the Sea Lions Gone?

Essential Question: None.

BIOZONE: 232-236 due Today!!!

Population Decline Case Study:Why Have all the Sea Lions Gone?

BIOZONE: 232-236Please open them to pg. 226 and turn in to Mrs. McC

“Mystery in Alaska: Why Have All The Sea Lions Gone?”

Background Information: Steller Sea Lions• Please read/highlight the Steller Sea Lion information sheet• Note key details on their diet (food habits), population size, and

predators/hunting

“A Mystery in Alaska”- Clip • https://www.youtube.com/watch?v=_fBneJlJwZU

• Please take 5-10 bullets on the video on pg. 22

Mystery in AlaskaWith a Partner please read and answer the questions in the case study• Part I

• Part II

• Part III• Make sure you do the calculations properly!

Discussion to Follow

Discussion Questions• What were several possible reasons for the decline of the Steller Sea Lion population?• How would the shift in fish populations affect the diets of the Western and Eastern

stocks of sea lions? (decrease Herring, increase Pollock)• Describe an experiment that could be used to test your hypothesis for why the

Western stock #s were decreasing, but the Eastern stock #s were slowing increasing. Make sure to include your hypothesis.• What experiment was conducted at the Vancouver Aquarium to compare the effects

of eating Pollock and herring?• Based on your calculations, which fish better meets the energy needs of the Steller

sea lions?• Why do you think the sea lions lost weight when they were aloud to eat unlimited

amounts of Pollock in the experiment? • What is the significance that sea lion pups were affected more than adults? Why were

they especially impacted?

Steller Sea Lion Population Decline and Increase

The Good News…