Copyright Pearson Prentice Hall How Populations Grow Photo Credit: © Frans Lanting/Minden Pictures, Inc. Copyright Pearson Prentice Hall

Characteristics of Populations A population is a group of the same organisms living in the same place at the same time.? Copyright Pearson Prentice Hall

Characteristics of Populations -The increase OR decrease of the population size is its growth rate. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Population Growth Population Growth 3 factors can affect population size: # of births # of deaths Immigration/Emigration Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall # Births = population # Deaths = population Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Population Growth Immigration- the movement of individuals into an area, (I=into=immigration) Animals Immigrate in search of mates/food. Population= Emigration- the movement of individuals out of an area (E=Exit=Emigration) Caused by: leaving to find mate, food Population = Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall B D A C Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall A=increase B=decrease C=stay the same A B C Immigration Greater than emigration A B C Emigration greater than immigration A B C A B C #Births=#deaths # Immigration= # emigration A B C A B C # births greater than # deaths #deaths greater than # births Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall http://player.discoveryeducation.com/index.cfm?guidAssetId=E86B71B6-066F-49D2-8F91-43AC8D34E1AB&blnFromSearch=1 Africa: World’s best series: amazing swarms Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Exponential Growth What are exponential growth and logistic growth? Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 2 Types of Growth Rates Types of Growth Rates 1.Exponential growth- occurs when the population grows at a constant rate Required Conditions: Unlimited resources Ideal conditions- Plenty of food, water, land, mates Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Exponential Growth Exponential Growth In the presence of unlimited resources and in the absence of predation and disease, a population will grow exponentially. Both hypothetical graphs show the characteristic J-shape of exponential population growth. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Logistic Growth Types of Growth Rates 2.Logistics growth – occurs when a population’s growth slows or stops due to limited resources because of increased competition. (With shoulder partner, find 3 things that can stop Exponential Growth) Required Conditions: Resources become less available Increased competition Carrying Capacity is reached Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Logistic Growth Carrying Capacity of the environment is -the maximum # of individuals an environment can support over a long period of time. When a population reaches the carrying capacity of its environment, growth levels off. (The average growth rate is zero.) This graph shows the S-shaped curve of logistic growth. As resources become less available, the population growth rate slows or stops. The growth of this population has leveled off at its carrying capacity. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Limits to Growth Limits to Growth Limiting Factor- ANYTHING that causes population growth to decrease (face partners list-try to get 10 limiting factors in 2 minutes) Share your list w/your whole team and add their items to your list (T-chart) Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Limits to Growth A Density-dependant limiting factor is based on the size of the population. The size of the population determines if the factor causes the population to grow or decrease. (EX: Disease-The more dense the population is the close they are and the more chance of spreading) With your team come up with an example for each one below. Competition, Predation, Parasitism, Competition Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall A Density Independent Factor affect all populations the same(equally) regardless of their size. Their population is reduced by the same proportion (Ex: if a dam stops flow of river water, population of fish downstream will die regardless of 1 or 1000 fish). Natural disasters Unusual weather Human activities – clear cutting; damming rivers Copyright Pearson Prentice Hall

Density Independent or Dependent? Will small and large populations be affected the same way? Yes/No…….Dependent/Independent Examples: Competition Food shortage Disease Human activities Parasitism Predation Natural Disasters (fire, flood, hurricane) Copyright Pearson Prentice Hall 19

Copyright Pearson Prentice Hall Community A community is a group of populations living in the same place at the same time. Copyright Pearson Prentice Hall

Community Interactions Predator/Prey) -Predation is when one organism captures and feeds on another organism Predator-does the killing/eating Prey-killed/eaten #Predators __ then #Prey _____ #Predators ___ then #Prey _____ Competition is when 2 or more members of the same or different populations fight over the same limited resources such as Land, food, and mates Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall http://www.phschool.com/webcodes10/index.cfm?wcprefix=cbe&wcsuffix=2059&area=view&x=16&y=13 Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Limited mates Loss of land to human activity Limited water due to drought Increased death rate caused by disease Increased birth rate due to lack of predators Which can cause a change in Carrying Capacity B D A C Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Killer whales fighting over a sea lion Hurricane Katrina flooding Louisiana A great white hunting seals Tapeworms in the intestines of a wolf population The bird flu killing dense populations of birds Density dependent vs Density Independent B D A C Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall B D A Copyright Pearson Prentice Hall

Ecological Succession Ecological succession is the gradual and sequential regrowth of a community in an area . Copyright Pearson Prentice Hall

Ecological Succession Ecological Succession (READ ONLY-IMPORTANT) Ecosystems are constantly changing in response to natural and human disturbances. As an ecosystem changes, older inhabitants gradually die out and new organisms move in, causing further changes in the community. Copyright Pearson Prentice Hall

Ecological Succession Primary succession is when a community develops in an area where no life had been before. EX: Hardened lava, sand dunes, bare rock ORDER OF SUCCESSION: Lichens, grasses, shrubs, trees Copyright Pearson Prentice Hall

Draw/Label Primary Succession and be ready to present Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Pioneer species----- -The first species to populate a new area where there was no life before are lichens. (fungus/alga-break apart rock and become soil as they die) Copyright Pearson Prentice Hall

Ecological Succession In this example, a volcanic eruption has destroyed the previous ecosystem. Primary succession occurs on newly exposed surfaces, such as this newly deposited volcanic rock and ash. Copyright Pearson Prentice Hall

Ecological Succession The first organisms to appear are lichens. Primary succession occurs on newly exposed surfaces, such as this newly deposited volcanic rock and ash. Copyright Pearson Prentice Hall

Ecological Succession Mosses soon appear, and grasses take root in the thin layer of soil. Primary succession occurs on newly exposed surfaces, such as this newly deposited volcanic rock and ash. Copyright Pearson Prentice Hall

Ecological Succession Eventually, tree seedlings and shrubs sprout among the plant community. Primary succession occurs on newly exposed surfaces, such as this newly deposited volcanic rock and ash. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall In your notes (w/shoulder partner) explain why the population of predators will increase/decrease along with the population of its prey. P. 388. Does this make the predator/prey relationship a good method of population control? Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall B D A C Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 5-1 Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 5-1 Population density is the number of individuals that are born each year. per unit area. that immigrate. that emigrate. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 5-1 When the birthrate of a population exceeds its death rate, the population decreases. increases. stays the same. increases then decreases. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 5-1 An S-shaped curve on a graph of population growth is characteristic of exponential growth. logistic growth. carrying capacity. delayed growth. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 5-1 Exponential growth in a population slows down or stops as resources become limited. rate of immigration increases. rate of emigration decreases. birth rate increases. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 5-1 Exponential growth rate means that each new generation of a population adds the same number of new individuals as the previous generation did. increases at the same rate as the previous generation. is the same size as the generation before. increases by a varying amount. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Exponential Growth Exponential Growth Ideal conditions/unlimited resources, a population will grow exponentially. Individuals in a population reproduce at a constant/non-stop rate. The population becomes larger and larger until it approaches an infinitely large size. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Logistic Growth Logistic Growth In nature, exponential growth does not continue in a population for very long. -W/shoulder partner, find 3 things that can stop Exponential Growth As resources become less available, the growth of a population slows or stops. Logistic growth occurs when a population's growth slows or stops following a period of exponential growth Copyright Pearson Prentice Hall

“I Want to be a billionaire so freakin bad!” Would you take a job where they paid you .01/day? What if they doubled it each day? W/your shoulder partner try to figure out what the pay would be at the end of each week and graph it. (Use a a line graph like the one you just saw-units of time will go on horizontal axis, amount of money/pay will go on vertical axis) Copyright Pearson Prentice Hall

Ecological Succession -Series of predictable changes that occur in a community -Ecosystems can change due to natural disasters, or human disasters -Can be sudden, or gradual ecological succession--- Copyright Pearson Prentice Hall

END OF SECTION