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

Characteristics of Populations Group of the same organisms living in the same place at the same time. Copyright Pearson Prentice Hall

Characteristics of Populations -The area a population Lives in is called geographic distribution -Population density is the number of individuals in the area. -The increase OR decrease of the population size is its growth rate. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Population Growth Population Growth Four 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 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 (team 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, Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall A Density Independent Factor reduces 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-Dependent Factors The size of a population determines if the factor will cause the population to grow or decrease. An individuals chance of surviving depends on the number of individuals in the same area. Copyright Pearson Prentice Hall 16

Density-Independent Factors Affect all populations in similar ways regardless of size. The population reduces by the same proportions no matter what size the population is. LUCK!!! Copyright Pearson Prentice Hall 17

Density Independent or Dependent? Will small and large populations be affected the same way? independent, Dependent Examples: Competition Food shortage Disease Human activities Parasitism Predation Natural Disasters (fire, flood, hurricane) Copyright Pearson Prentice Hall 18

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 Predator Prey Video http://www.pbs.org/wnet/nature/lessons/survival-of-the-fastest-predators-and-prey-on-the-african-savannah/video-segments/5662/ http://video.nationalgeographic.com/video/hawk_redtailed_rattlesnakemeal http://www.youtube.com/watch?v=hPge_0lea3o​ http://www.pbs.org/wnet/nature/lessons/survival-of-the-fastest-predators-and-prey-on-the-african-savannah/video-segments/5662/​ Copyright Pearson Prentice Hall

Community Interactions Symbiosis is When 2 different organisms/species live in a close/long term relationship (sounds like what?) . Includes: 3 types mutualism commensalism parasitism Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall SYMBIOSIS (CONT) Mutualism- Both species benefit from the relationship Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall SYMBIOSIS (CONT) Commensalism- one organism is helped, the other is not harmed/helped. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Parasitism- relationship where one organism harms another for its own benefit 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 Video https://www.youtube.com/watch?v=V49IovRSJDs Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Video “mini quiz” Explain to your face partner what ecological succession is. Tell you shoulder what the difference is between primary and secondary succession. With your shoulder partner come up with one example of each type of succession Define a pioneer species with your whole team 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

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

Draw/Label Primary Succession and be ready to present 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