This document provides an outline of key topics from Chapter 36 on population ecology. It discusses how ecology can be studied at different levels from organisms to ecosystems. It also covers concepts such as population density and distribution, factors that influence population growth rates, survivorship curves, exponential and logistic growth models, and density-dependent and density-independent limiting factors. The chapter utilizes figures and diagrams to illustrate these ecological principles.
This document is an outline for Chapter 38 of an ecology textbook. It covers several key topics:
1) Competition can lead to resource partitioning between species to decrease competition. Predator-prey interactions also affect population numbers of both species.
2) Antipredator defenses in prey include camouflage, warning coloration, and mimicry. Parasitism involves a parasite infecting a host, while commensalism benefits one species without affecting the other.
3) Mutualism benefits both participant species, like the relationship between plants and pollinators. Ecological succession is the replacement of species over time after a disturbance.
1. Aquatic ecosystems provide important ecological and economic services but are poorly understood. Further scientific study could lead to benefits.
2. Human activities like pollution, development, and overfishing are severely degrading aquatic habitats and reducing biodiversity.
3. We can sustain aquatic life by creating protected areas, managing development, reducing pollution, and preventing overfishing.
This chapter outline discusses key topics in conservation biology including:
1) The goals of conservation biology are to conserve natural resources for current and future generations and support biodiversity by reducing species extinctions.
2) There is high biodiversity on Earth between 10-50 million species, but nearly 1,200 in the US and 40,000 worldwide are endangered.
3) Conserving genetic, ecosystem, and landscape diversity helps preserve species and ecosystems.
Organic agriculture is growing in popularity worldwide as a more sustainable alternative to industrial agriculture. However, many people still suffer from malnutrition due to lack of access to sufficient nutritious food. Soil erosion, overuse of water, and pesticide pollution threaten global food security. More sustainable practices like organic farming, conservation tillage, integrated pest management, and restoring degraded lands can help address these challenges.
This document discusses trends in urbanization and sustainability issues facing cities. It notes that half the world's population now lives in urban areas, with migration from rural to urban areas driven by factors like poverty and lack of opportunity. As urban populations grow, issues around sprawl, pollution, poverty, and transportation have emerged. The document examines strategies some cities are using to promote compact growth, reduce car dependence, preserve open space, and generally enhance sustainability.
The document outlines different ecosystems of the biosphere, including how solar radiation, winds, and topography influence climate. It discusses various land ecosystems like tundra, forests, grasslands, deserts that exist in different regions due to climate factors. Freshwater ecosystems like streams and lakes are described along with coastal ecosystems. Finally, marine ecosystems are covered, including ocean zones and coral reefs.
This chapter discusses economics, the environment, and sustainability. It covers the following key points in 3 sentences:
Economic systems depend on natural, human, and manufactured capital. Markets fail to fully account for environmental costs, so governments intervene through various policies. Moving to a more sustainable economy will require shifting subsidies from polluting to green industries, taxing pollution over profits, and creating new green jobs in renewable energy and recycling.
The document provides an outline of key topics in evolution of animals, including:
1) Animals have distinctive characteristics like being multicellular, heterotrophic, and often sexually reproducing. They have muscles, nerves, and various types of symmetry.
2) Early animal phyla include sponges, cnidarians, flatworms, roundworms, and molluscs which have features like radial or bilateral symmetry and the presence or absence of tissues and body cavities.
3) More complex animals include segmented worms, arthropods like insects and crustaceans, echinoderms, and chordates including vertebrates. These groups show increasing complexity in anatomy, tissues, and organ systems.
This document is an outline for Chapter 38 of an ecology textbook. It covers several key topics:
1) Competition can lead to resource partitioning between species to decrease competition. Predator-prey interactions also affect population numbers of both species.
2) Antipredator defenses in prey include camouflage, warning coloration, and mimicry. Parasitism involves a parasite infecting a host, while commensalism benefits one species without affecting the other.
3) Mutualism benefits both participant species, like the relationship between plants and pollinators. Ecological succession is the replacement of species over time after a disturbance.
1. Aquatic ecosystems provide important ecological and economic services but are poorly understood. Further scientific study could lead to benefits.
2. Human activities like pollution, development, and overfishing are severely degrading aquatic habitats and reducing biodiversity.
3. We can sustain aquatic life by creating protected areas, managing development, reducing pollution, and preventing overfishing.
This chapter outline discusses key topics in conservation biology including:
1) The goals of conservation biology are to conserve natural resources for current and future generations and support biodiversity by reducing species extinctions.
2) There is high biodiversity on Earth between 10-50 million species, but nearly 1,200 in the US and 40,000 worldwide are endangered.
3) Conserving genetic, ecosystem, and landscape diversity helps preserve species and ecosystems.
Organic agriculture is growing in popularity worldwide as a more sustainable alternative to industrial agriculture. However, many people still suffer from malnutrition due to lack of access to sufficient nutritious food. Soil erosion, overuse of water, and pesticide pollution threaten global food security. More sustainable practices like organic farming, conservation tillage, integrated pest management, and restoring degraded lands can help address these challenges.
This document discusses trends in urbanization and sustainability issues facing cities. It notes that half the world's population now lives in urban areas, with migration from rural to urban areas driven by factors like poverty and lack of opportunity. As urban populations grow, issues around sprawl, pollution, poverty, and transportation have emerged. The document examines strategies some cities are using to promote compact growth, reduce car dependence, preserve open space, and generally enhance sustainability.
The document outlines different ecosystems of the biosphere, including how solar radiation, winds, and topography influence climate. It discusses various land ecosystems like tundra, forests, grasslands, deserts that exist in different regions due to climate factors. Freshwater ecosystems like streams and lakes are described along with coastal ecosystems. Finally, marine ecosystems are covered, including ocean zones and coral reefs.
This chapter discusses economics, the environment, and sustainability. It covers the following key points in 3 sentences:
Economic systems depend on natural, human, and manufactured capital. Markets fail to fully account for environmental costs, so governments intervene through various policies. Moving to a more sustainable economy will require shifting subsidies from polluting to green industries, taxing pollution over profits, and creating new green jobs in renewable energy and recycling.
The document provides an outline of key topics in evolution of animals, including:
1) Animals have distinctive characteristics like being multicellular, heterotrophic, and often sexually reproducing. They have muscles, nerves, and various types of symmetry.
2) Early animal phyla include sponges, cnidarians, flatworms, roundworms, and molluscs which have features like radial or bilateral symmetry and the presence or absence of tissues and body cavities.
3) More complex animals include segmented worms, arthropods like insects and crustaceans, echinoderms, and chordates including vertebrates. These groups show increasing complexity in anatomy, tissues, and organ systems.
The document outlines the life cycle and reproductive processes in flowering plants. It describes the alternation of generations between diploid sporophytes and haploid gametophytes. The sporophyte produces spores via meiosis and the gametophyte generates gametes. Fertilization occurs when sperm fertilizes an egg, forming a zygote that develops into a seed containing an embryo. The ovary becomes a fruit, dispersing seeds that can germinate to form new sporophytes, completing the cycle. Flowers are adaptations that produce and protect gametophytes and attract pollinators like insects and birds to facilitate fertilization.
Plants transport water and nutrients throughout their systems using two transport tissues: xylem and phloem. Xylem transports water and minerals absorbed by the roots up to the leaves, relying on the cohesion-tension model. Transpiration through leaf stomata creates a pulling force that draws the water column through the xylem. Phloem transports sugars made in leaves to all parts of the plant using pressure flow, with a concentration gradient driving the movement of sugars from sources to sinks. Guard cells regulate stomatal openings to control water loss through transpiration. Plants require certain essential nutrients obtained from the soil to complete their life cycles.
This document discusses solid and hazardous waste. It notes that developed countries produce the majority of hazardous waste. Various methods for managing solid and hazardous waste are discussed, including reducing waste production, reuse, recycling, composting, burning, burying, and long-term storage. Integrated waste management is presented as using a variety of these strategies together. Citizen action and policy changes are needed to further encourage waste reduction and sustainable management.
This document provides an outline of Chapter 21 from a biology textbook. It discusses plant organization and homeostasis. It begins by describing the basic shoot and root systems of flowering plants, including stems, leaves, branches, and roots. It then explains how plants are categorized as monocots or eudicots based on structural differences. The document outlines the three main tissue types found in plants - epidermal, ground, and vascular tissue - and how they are arranged and function in leaves, stems, and roots. It concludes by describing primary growth and how it causes lengthening of the root and shoot systems through cell division in the meristems located at the tips.
This document provides an outline on the evolution of plants and fungi. It discusses how plants evolved from green algae around 500 million years ago, sharing characteristics like chlorophyll and starch storage. It then describes the alternation of generations life cycle, with multicellular sporophyte and gametophyte stages that alternate. Having a dominant sporophyte generation allowed plants to grow larger and adapt to dry land by developing vascular tissue for water transport. Seed plants further enhanced reproduction in dry conditions by protecting eggs in ovules.
The document discusses various sources and impacts of water pollution. It describes point sources like industrial facilities that pollute water at specific locations, and nonpoint sources like agricultural runoff that are diffuse and hard to regulate. Major causes of water pollution include agriculture, industry, and mining. Water pollutants can harm human health and aquatic ecosystems. Solutions discussed include better regulation, pollution prevention, water treatment and protecting watersheds.
This document discusses climate change and ozone depletion. It describes the difference between weather and climate, and how the climate has changed naturally over billions of years due to various factors. However, the climate is now changing faster due to human emissions of greenhouse gases from burning fossil fuels and deforestation. This is causing the atmosphere and oceans to warm, glaciers and ice sheets to melt, and sea levels to rise. Unless emissions are reduced, the consequences could be severe, including more extreme weather, worsening droughts and wildfires, flooded coastlines, and disrupted ecosystems. The document also discusses efforts to mitigate and adapt to climate change through reducing emissions and preparing for impacts. Finally, it covers the issue of ozone depletion from
This document discusses air pollution, its sources, impacts, and solutions. It covers outdoor pollution from industrial activities and vehicles, as well as indoor pollution from burning biomass. Key points are that air pollution causes over 2 million premature deaths annually, with indoor pollution responsible for about two-thirds of deaths, primarily in developing countries. Solutions discussed include pollution prevention and regulations in developed countries, as well as cleaner cooking technologies in developing world contexts.
1. Humans face health risks from infectious diseases, chemicals that cause cancer and birth defects, and chemicals that disrupt human systems.
2. It is difficult to evaluate harm from chemical exposure, so some experts advocate pollution prevention.
3. Being informed, thinking critically about risks, and making careful choices can reduce major health risks.
This document discusses various methods for improving energy efficiency and increasing the use of renewable energy sources. It begins by explaining how much energy is wasted through inefficient devices like incandescent light bulbs and internal combustion engines. It then outlines strategies for saving energy in industry, transportation, buildings, and individuals' daily lives. The document dedicates several sections to different renewable energy sources like solar, wind, hydropower, biomass and biofuels. It discusses the advantages and challenges of each approach while providing examples of existing technologies and projects around the world. The overall message is that transitioning to more efficient use of energy and greater renewable sources can provide economic, environmental and national security benefits.
1. Net energy yield is an important factor in evaluating energy resources, as it accounts for the energy needed to extract and produce the resource.
2. While fossil fuels like oil, natural gas, and coal are plentiful, they have high environmental impacts, especially coal which is a major contributor to air pollution and carbon emissions.
3. Nuclear power has low carbon emissions but produces long-lived radioactive waste and has high costs, low net energy yield, and safety concerns that have limited its expansion.
This document provides an outline of Chapter 16 from a textbook on microbial life and evolution. It discusses the basic structure and classification of viruses. It describes how some viruses reproduce inside bacteria through lytic and lysogenic cycles. Examples of plant diseases caused by viruses are given. Emergent viral diseases in humans are discussed, including influenza, SARS, Ebola, and avian influenza. The life cycle of an animal DNA virus is outlined, from attachment to a host cell through biosynthesis, maturation and release of new viral particles.
This document provides an outline of key topics in the evolution of protists. It discusses how protists are a diverse group of mostly unicellular eukaryotes that are not animals, fungi, or plants. They range in size and have various modes of nutrition and reproduction. Examples are provided of different protist groups like flagellates, amoebas, ciliates, and apicomplexans. Aquatic algae examples like diatoms, dinoflagellates, red algae, brown algae, and green algae are also outlined. Diagrams illustrate cellular features and life cycles of select protist species.
This document is a lecture outline on Charles Darwin and the theory of evolution. It covers Darwin's voyage on the HMS Beagle where he made observations of animals in different parts of the world. It discusses how Darwin was influenced by earlier scientists like Cuvier and Lamarck and how he developed the theory of natural selection based on his observations of variations between individuals and how certain traits could provide advantages for survival and reproduction. The document outlines Darwin's key ideas of natural selection and variation within populations. It also notes that Alfred Wallace independently developed a similar theory of natural selection.
This chapter discusses speciation and evolution. It defines speciation as the splitting of one species into two or more new species over time. Speciation occurs through both allopatric speciation, where a geographic barrier causes populations to evolve separately, and sympatric speciation, where speciation occurs without a geographic barrier. The chapter outlines models of gradualistic versus punctuated equilibrium for the pace of speciation and evolution. It also discusses how regulatory genes can bring about changes in body shapes during speciation and that evolution is not goal-oriented.
This document discusses nonrenewable mineral resources and geology. It describes how tectonic plates interact at divergent, convergent, and transform boundaries, causing volcanoes, earthquakes, and tsunamis. Mining has harmful environmental effects like pollution, waste, and land disruption. Supply of minerals depends on reserves, usage rate, and effects of extraction and use. More sustainable practices include reducing waste, recycling, and substituting scarce resources.
1) Freshwater scarcity is a major environmental problem as population grows and climate changes.
2) Water supplies can be increased by reducing overall use and waste through more sustainable practices like cutting irrigation inefficiencies, recycling water, and using pricing to reduce demand.
3) Specifically, conserving forests, wetlands, and aquifers that store and release water can help use limited supplies more sustainably along with other measures to cut residential and industrial water waste.
Slideshare is a platform for sharing PowerPoint presentations that allows users to search for presentations on topics, upload their own presentations, and add video or audio to PowerPoint files.
1. Forests vary in their composition, age, and origins. Old-growth forests preserve biodiversity while second-growth and tree plantations may supply wood.
2. Forests provide important economic and ecological services like supporting nutrient cycles, absorbing water, and providing habitat but unsustainable logging threatens biodiversity.
3. Protecting biodiversity hotspots and rehabilitating damaged ecosystems can help conserve species and restore natural capital around the world.
This document discusses several key concepts in human genetics including Mendel's laws, patterns of inheritance, genetic disorders, and advances in genetic testing. Some key points are:
- Pedigrees can show if a genetic condition is dominant or recessive based on patterns of affected individuals.
- Some common autosomal recessive disorders include Tay-Sachs disease, cystic fibrosis, PKU, and sickle cell disease. Autosomal dominant disorders include neurofibromatosis, Huntington disease, and achondroplasia.
- Genetic testing like amniocentesis and chorionic villi sampling can now detect disorders early in pregnancy. Preimplantation testing can analyze embryos or eggs.
The document outlines the life cycle and reproductive processes in flowering plants. It describes the alternation of generations between diploid sporophytes and haploid gametophytes. The sporophyte produces spores via meiosis and the gametophyte generates gametes. Fertilization occurs when sperm fertilizes an egg, forming a zygote that develops into a seed containing an embryo. The ovary becomes a fruit, dispersing seeds that can germinate to form new sporophytes, completing the cycle. Flowers are adaptations that produce and protect gametophytes and attract pollinators like insects and birds to facilitate fertilization.
Plants transport water and nutrients throughout their systems using two transport tissues: xylem and phloem. Xylem transports water and minerals absorbed by the roots up to the leaves, relying on the cohesion-tension model. Transpiration through leaf stomata creates a pulling force that draws the water column through the xylem. Phloem transports sugars made in leaves to all parts of the plant using pressure flow, with a concentration gradient driving the movement of sugars from sources to sinks. Guard cells regulate stomatal openings to control water loss through transpiration. Plants require certain essential nutrients obtained from the soil to complete their life cycles.
This document discusses solid and hazardous waste. It notes that developed countries produce the majority of hazardous waste. Various methods for managing solid and hazardous waste are discussed, including reducing waste production, reuse, recycling, composting, burning, burying, and long-term storage. Integrated waste management is presented as using a variety of these strategies together. Citizen action and policy changes are needed to further encourage waste reduction and sustainable management.
This document provides an outline of Chapter 21 from a biology textbook. It discusses plant organization and homeostasis. It begins by describing the basic shoot and root systems of flowering plants, including stems, leaves, branches, and roots. It then explains how plants are categorized as monocots or eudicots based on structural differences. The document outlines the three main tissue types found in plants - epidermal, ground, and vascular tissue - and how they are arranged and function in leaves, stems, and roots. It concludes by describing primary growth and how it causes lengthening of the root and shoot systems through cell division in the meristems located at the tips.
This document provides an outline on the evolution of plants and fungi. It discusses how plants evolved from green algae around 500 million years ago, sharing characteristics like chlorophyll and starch storage. It then describes the alternation of generations life cycle, with multicellular sporophyte and gametophyte stages that alternate. Having a dominant sporophyte generation allowed plants to grow larger and adapt to dry land by developing vascular tissue for water transport. Seed plants further enhanced reproduction in dry conditions by protecting eggs in ovules.
The document discusses various sources and impacts of water pollution. It describes point sources like industrial facilities that pollute water at specific locations, and nonpoint sources like agricultural runoff that are diffuse and hard to regulate. Major causes of water pollution include agriculture, industry, and mining. Water pollutants can harm human health and aquatic ecosystems. Solutions discussed include better regulation, pollution prevention, water treatment and protecting watersheds.
This document discusses climate change and ozone depletion. It describes the difference between weather and climate, and how the climate has changed naturally over billions of years due to various factors. However, the climate is now changing faster due to human emissions of greenhouse gases from burning fossil fuels and deforestation. This is causing the atmosphere and oceans to warm, glaciers and ice sheets to melt, and sea levels to rise. Unless emissions are reduced, the consequences could be severe, including more extreme weather, worsening droughts and wildfires, flooded coastlines, and disrupted ecosystems. The document also discusses efforts to mitigate and adapt to climate change through reducing emissions and preparing for impacts. Finally, it covers the issue of ozone depletion from
This document discusses air pollution, its sources, impacts, and solutions. It covers outdoor pollution from industrial activities and vehicles, as well as indoor pollution from burning biomass. Key points are that air pollution causes over 2 million premature deaths annually, with indoor pollution responsible for about two-thirds of deaths, primarily in developing countries. Solutions discussed include pollution prevention and regulations in developed countries, as well as cleaner cooking technologies in developing world contexts.
1. Humans face health risks from infectious diseases, chemicals that cause cancer and birth defects, and chemicals that disrupt human systems.
2. It is difficult to evaluate harm from chemical exposure, so some experts advocate pollution prevention.
3. Being informed, thinking critically about risks, and making careful choices can reduce major health risks.
This document discusses various methods for improving energy efficiency and increasing the use of renewable energy sources. It begins by explaining how much energy is wasted through inefficient devices like incandescent light bulbs and internal combustion engines. It then outlines strategies for saving energy in industry, transportation, buildings, and individuals' daily lives. The document dedicates several sections to different renewable energy sources like solar, wind, hydropower, biomass and biofuels. It discusses the advantages and challenges of each approach while providing examples of existing technologies and projects around the world. The overall message is that transitioning to more efficient use of energy and greater renewable sources can provide economic, environmental and national security benefits.
1. Net energy yield is an important factor in evaluating energy resources, as it accounts for the energy needed to extract and produce the resource.
2. While fossil fuels like oil, natural gas, and coal are plentiful, they have high environmental impacts, especially coal which is a major contributor to air pollution and carbon emissions.
3. Nuclear power has low carbon emissions but produces long-lived radioactive waste and has high costs, low net energy yield, and safety concerns that have limited its expansion.
This document provides an outline of Chapter 16 from a textbook on microbial life and evolution. It discusses the basic structure and classification of viruses. It describes how some viruses reproduce inside bacteria through lytic and lysogenic cycles. Examples of plant diseases caused by viruses are given. Emergent viral diseases in humans are discussed, including influenza, SARS, Ebola, and avian influenza. The life cycle of an animal DNA virus is outlined, from attachment to a host cell through biosynthesis, maturation and release of new viral particles.
This document provides an outline of key topics in the evolution of protists. It discusses how protists are a diverse group of mostly unicellular eukaryotes that are not animals, fungi, or plants. They range in size and have various modes of nutrition and reproduction. Examples are provided of different protist groups like flagellates, amoebas, ciliates, and apicomplexans. Aquatic algae examples like diatoms, dinoflagellates, red algae, brown algae, and green algae are also outlined. Diagrams illustrate cellular features and life cycles of select protist species.
This document is a lecture outline on Charles Darwin and the theory of evolution. It covers Darwin's voyage on the HMS Beagle where he made observations of animals in different parts of the world. It discusses how Darwin was influenced by earlier scientists like Cuvier and Lamarck and how he developed the theory of natural selection based on his observations of variations between individuals and how certain traits could provide advantages for survival and reproduction. The document outlines Darwin's key ideas of natural selection and variation within populations. It also notes that Alfred Wallace independently developed a similar theory of natural selection.
This chapter discusses speciation and evolution. It defines speciation as the splitting of one species into two or more new species over time. Speciation occurs through both allopatric speciation, where a geographic barrier causes populations to evolve separately, and sympatric speciation, where speciation occurs without a geographic barrier. The chapter outlines models of gradualistic versus punctuated equilibrium for the pace of speciation and evolution. It also discusses how regulatory genes can bring about changes in body shapes during speciation and that evolution is not goal-oriented.
This document discusses nonrenewable mineral resources and geology. It describes how tectonic plates interact at divergent, convergent, and transform boundaries, causing volcanoes, earthquakes, and tsunamis. Mining has harmful environmental effects like pollution, waste, and land disruption. Supply of minerals depends on reserves, usage rate, and effects of extraction and use. More sustainable practices include reducing waste, recycling, and substituting scarce resources.
1) Freshwater scarcity is a major environmental problem as population grows and climate changes.
2) Water supplies can be increased by reducing overall use and waste through more sustainable practices like cutting irrigation inefficiencies, recycling water, and using pricing to reduce demand.
3) Specifically, conserving forests, wetlands, and aquifers that store and release water can help use limited supplies more sustainably along with other measures to cut residential and industrial water waste.
Slideshare is a platform for sharing PowerPoint presentations that allows users to search for presentations on topics, upload their own presentations, and add video or audio to PowerPoint files.
1. Forests vary in their composition, age, and origins. Old-growth forests preserve biodiversity while second-growth and tree plantations may supply wood.
2. Forests provide important economic and ecological services like supporting nutrient cycles, absorbing water, and providing habitat but unsustainable logging threatens biodiversity.
3. Protecting biodiversity hotspots and rehabilitating damaged ecosystems can help conserve species and restore natural capital around the world.
This document discusses several key concepts in human genetics including Mendel's laws, patterns of inheritance, genetic disorders, and advances in genetic testing. Some key points are:
- Pedigrees can show if a genetic condition is dominant or recessive based on patterns of affected individuals.
- Some common autosomal recessive disorders include Tay-Sachs disease, cystic fibrosis, PKU, and sickle cell disease. Autosomal dominant disorders include neurofibromatosis, Huntington disease, and achondroplasia.
- Genetic testing like amniocentesis and chorionic villi sampling can now detect disorders early in pregnancy. Preimplantation testing can analyze embryos or eggs.
3. 36.1 Ecology is studied
at various levels
Ecology is the study of the interactions of organisms with
other organisms and with the physical environment
Ecology is wide-ranging
Habitat – the place where the organism lives
Population – all the organisms within an area belonging to the
same species
Community – all populations interacting at a locale (predation,
competition)
Ecosystem – encompasses a community of populations as well
as abiotic environment (sunlight, temperature, precipitation)
Biosphere – encompasses the zones of the Earth’s land, water,
and air where living organisms are found
36-3
5. 36.2 Population Density & Distribution
Density
Number of individuals per unit area
Distribution
Clumped, Random & Uniform
Limiting factors effect a populations range
36-5
7. Figure 36.2B Nesting colony of Cape gannets off the coast of New Zealand,
uniform distribution
36-7
8.
9. 36.3 The growth rate results in
population size changes
A population’s annual growth rate depends on
Number that are born & die each
Annual immigration (coming in) & emigration (leaving)
Biotic potential of a population is the highest
possible growth rate
Achieved when resources are unlimited
Rare in nature
36-9
10. 3 Types of Survivorship Curves
Three types of survivorship curves
Type I Survivorship: Mammals
They survive well past the midpoint of the life span, and
death does not come until near the end of the life span
Type II Survivorship: Hydras, songbirds, and small
mammals
Survivorship decreases at a constant rate throughout the life
span
Type III Survivorship: Many invertebrates and fishes
Most individuals will probably die very young
36-10
13. Exponential Growth
Exponential Growth
Results in j-shaped curve with 2 phases
Lag phase – Growth is slow because the number of
individuals in the population is small
Exponential growth phase – Growth is accelerating due to
biotic potential
Usually, exponential growth can only continue as long
as resources in the environment are unlimited
Ex: Human Population Growth 36-13
15. Logistic Growth
Logistic Growth – as resources decrease, population
growth levels off
S-shaped curve with 4 phases
Lag phase
Exponential growth phase
Deceleration phase
Stable equilibrium phase
Growth starts slowly, then goes through an exponential phase
Carrying Capacity: the maximum number of organisms an
ecosystem can support.
36-15
17. Density-independent factors
Density-independent factors affect growth
Percentage of individuals killed remains the same regardless
of the population size
Abiotic (or “non-living”) factors
Exs: drought, fire, freezes, hurricanes, floods
Example: A drought on the Galápagos Islands
Caused the population size of finches to decline from 1,400
to 200 individuals
36-17
18. Density-dependent factors a
Biotic (or “living”) factors:
Competition – when members of same species
attempt to use needed resources
Predation – when one living organism, the predator,
eats another, the prey
36-18
20. Figure 36.6B Predation has a density-dependent effect. At left, when
density is low only two mice cannot find a place to hide and the hawk
cannot find them (predation rate = 0%). At right, when density is
high, 100 mice are unable to hide, and the hawk captures say ½ of
them (predation rate = 50%)
36-20
21. Opportunistic populations
Opportunistic populations – live in a
fluctuating and/or unpredictable environments
Exs: dandelions, mice
http://www.youtube.com/watch?v=RTIlOlVT3LI
36-21
23. Equilibrium populations
Equilibrium populations – live in relatively
stable and predictable environments
Logistic population growth, and remains close to , or
at, carrying capacity
Exs: oaks, pines, hawks, eagles, whales, elephants,
bears, gorillas
36-23
25. Extinction
Extinction is the total disappearance of a
species or higher group
Slow to mature, few offspring, specialists,
pretty, valuable to humans
http://www.youtube.com/watch?v=NNmTLLmhxFQ
http://www.youtube.com/watch?v=LaQd7Zfqj7g
36-25
26. 36.8 World population growth is
exponential
World’s population has risen steadily to a
present size of about 6.8 billion people
Doubling time: the length of time it takes for the
population size to double
Currently, the doubling time is about 51 years
In 51 years, the world would need double the amount of food,
jobs, water, energy, and so on just to maintain the present
standard of living
Carrying capacity ?
36-26
29. Connecting the Concepts: Ch. 36
Population density & distribution
3 types of Survivorship Curves
Exponential vs. Logistic Growth
Density-independent & Density-dependent Factors
Human population growth rates worldwide
36-29