COMPENDIUM REVIEW #2 FOR UNIT #4

TABLE OF CONTENTS

CHAPTER 22 - HUMAN EVOLUTION
1. ORIGIN OF LIFE
a. Primitive earth
b. Small organic molecules
c. Macromolecules
d. Protocell
e. True cell
2. BIOLOGICAL EVOLUTION
a. Common descent
b. Intelligent design
c. Natural selection
3. CLASSIFICATION OF HUMANS
a. DNA data and human evolution
b. Humans are primates
c. Comparison
4. EVOLUTION OF HOMINIDS
a. First hominids
b. Features
c. Earliest fossil
d. Australopithercines
e. Southern Africa
f. Eastern Africa
5. EVOLUTION OF HUMANS
a. Early homo
b. Modern humans
c. Neandertals
d. Cro-magnons
e. Human variation

CHAPTER 23 - GLOBAL ECOLOGY AND HUMAN INTERFERENCES
6. THE NATURE OF ECOSYSTEMS
a. Ecosystems
b. Biotic components
c. Energy flow and chemical cycling
7. ENERGY FLOW
a. Trophic levels
b. Ecological pyramids
8. GLOBAL BIOGEOCHEMICAL CYCLES
a. Water
b. Carbon
c. Nitrogen
d. Phosphorus

CHAPTER 24 - HUMAN POPULATION, PLANETARY RESOURCES AND CONSERVATION

9. HUMAN POPULATION GROWTH
a. MDC's versus LDC's
10. HUMAN USE OF RESOURCES AND POLLUTION
a. Land
b. Water
c. Food
d. Energy
e. Minerals
11. BIODIVERSITY
a. Loss
b. Direct value
c. Indirect value
12. WORKING TOWARD SUSTAINABLE SOCIETY
a. Today's unsustainable
b. Characteristics of sustainable
c. Assessing economic well being and quality of life

CHAPTER 22 - HUMAN EVOLUTION
Origin of Life

A fundamental principle of biology states that all living things are made of cells and that every cell comes from a preexisting cell. Could chemical evolution have produced that first cell?

Using outside energy source, small organic molecules were produced by reactions between early Earth's atmospheric gases. See illustration.*
Macromolecules evolved and interacted.

The RNA-first hypothesis was only macromolecule RNA was needed for the first cell.
The protein-first hypothesis was amino acids join to form polypeptides when exposed to dry heat.
The protocell lived on preformed organic molecules in the ocean. The protocell eventually became a true cell once it had genes composed of DNA and could reproduce.

BIOLOGICAL EVOLUTION

Biological evolution explains both the unity and diversity of life.

Descent from a common ancestor explains the unity of living things.

Adaptation to different environments explains the great diversity of living things.

The fossil record gives us the history of life in general and allows us to trace the descent of a particular group. This indeed says that fossil evidence supports evolution. See illustration.*

Darwin discovered evidence for common descent.

The distribution of organisms on Earth is explainable by assuming that organisms evolved in one locale. This is biogeographical evidence.
The common anatomies and development of a group of organisms are explainable by descent from a common ancestor. This is anatomical evidence.

All organisms have similar biochemical molecules. This is biochemical evidence.

Darwin also developed a mechanism for adaptation known as natural selection.

The result of natural selection is a population adapted to its local environment.

See illustration.*





CHAPTER 23 - GLOBAL ECOLOGY AND HUMAN INTERFERENCES

The Nature of Ecosystems

The study of the interactions of organisms with each other and with the physical environment is ecology. An ecosystem is organisms interacting with chemical and physical environment.



Forests, grasslands, and deserts, which include the tundra are all part of terrestrial ecosystems. See illustration.*

Aquatic ecosystems include either fresh or salt water. See illustration.*

Biotic components of an ecosystem. See illustration.*

In a community, each population has a habitat and a niche(role in the community).
Autotrophs produce organic nutrients for themselves and others from inorganic nutrients and an outside energy source.
Heterotrophs consume organic nutrients.

Consumers are herbivores, carnivores, and omnivores.

Decomposers feed on detritus, releasing inorganic substances back into the ecosystem.

Ecosystems are characterized by energy flow and chemical cycling.

Energy flows through the populations of an ecosystem and chemicals cycle within and among ecosystems. See illustration.*

ENERGY FLOW
Various interconnecting paths of energy flow are called a food web. A food web shows how various organisms are connecting by eating relationships.

Grazing food webs start with vegetation(for herbivores), that actually become food for a carnivore. Detrital food webs begin with detritus, food for decomposers and food for detritivores. Detrital food webs can be eaten by above ground carnivores, which join the two food groups together. See illustration.*

A trophic level is all organisms that feed at a particular link in a food chain.

An ecological pyramid is when the flow of energy with large losses between successive trophic levels.

GLOBAL BIOGEOCHEMICAL CYCLES

Chemicals circulate through ecosystems via biogeochemical cycles, pathways involving both biotic and geological components.

Biogeochemical cycles can be gaseous, sedimentary, have reservoirs that contain inorganic nutrients available to living things on a limited basis.

Exchange pools are sources of inorganic nutrients.

In biotic communities of an ecosystem, nutrients cycle among them.

Examples being fossil fuels, minerals in rocks, sediment in oceans, the atmosphere, soil and water.

In the water cycle, the reservoir is freshwater that evaporates from the ocean.

Water that falls on land enters the ground, surface water, or aquifers and evaporates again.

All water returns to the ocean. See illustration.*

In the carbon cycle, the reservoirs are organic matter, limestone, and the ocean.

The exchange pool is the atmosphere. Photosynthesis removes carbon dioxide from the atmosphere. Respiration and combustion add carbon dioxide to the atmosphere. See illustration.*

In the nitrogen cycle, the reservoir is the atmosphere. Nitrogen gas must be converted to a form usable by plants.

Nitrogen-fixing bacteria convert nitrogen gas to ammonium, a for plants can use. Nitrifying bacteria convert ammonium to nitrate.

Denitrifying bacteria convert nitrate back to nitrogen gas. See illustration.*



In the phosphorus cycle, the reservoir is the ocean sediments.

Phosphate in ocean sediments become available through geological upheaval, which exposes sedimentary rock to weathering.

Weathering slowly makes phosphate available to the biotic community. Phosphate is a limiting nutrient in ecosystems. See illustration.*

CHAPTER 24 - HUMAN POPULATION, PLANETARY RESOURCES AND CONSERVATION

HUMAN POPULATION GROWTH


Populations have a biotic potential for increase in size. Biotic potential is normally held in check by environmental resistance. Population size usually levels off at carrying capacity. See illustration.*

MDC'S (more-developed countries) have a .1% growth rate since 1950. The LDC (less-developed countries) growth rate is 1.6% after peaking at 2.5% in the 1960s. Age structure diagrams can be used to predict population growth. See illustration.*

MDC's are approaching a stable population size and LDC populations will continue to increase in size.

HUMAN USE OF RESOURCES AND POLLUTION
Land, water, food, energy, and minerals are the 5 resources maximally used by humans.
Some resources are nonrenewable and some are renewable. The nonrenewable resources are not replenished and are limited in quantity, like land, fossil fuels and minerals.
Renewable resources are replenished but still are limited in quantity, like water, solar energy, and food.

For land, human activities contribute to erosion, pollution, desertificaiton, deforestation and loss of biodiversity. These activities include habitation, farming and mining.

For water, industry and agriculture use most of the freshwater supply. Supplies are increased by damming rivers and drawing from aquifers. As aquifers are depleted, subsidence, sinkhole formation and saltwater intrusion can occur. Water conservation methods could cut world water consumption by half, if used by industries. See illustration.*

For food, food comes from growing crops, raising animals, and fishing. Modern farming methods increase the food supply, but some methods harm the land, pollute water, and consume fossil fuels excessively. Genetically engineered plants increase the food supply and reduce the need for chemicals.

Raising livestock contributes to water pollution and uses fossil fuel energy. The increased number and high efficiency of fishing boats have caused the world fish catch to decline.

For Energy, fossil fuels are nonrenewable, like oil, natural gas, and coal. When we burn fossil fuels to clear land for farming, causes pollutants and gases to enter the air.

Greenhouse gases include CO2 and other gases. These gases cause global warming because solar radiation can pass through, but infrared heat cannot escape back into space. Renewable resources include hydropower, geothermal, wind and solar power. See illustration.*

For minerals, they are nonrenewable resources that can be mined. These include, sand, gravel, phosphate, and metals. Mining causes destruction of the land by erosion, loss of vegetation, and toxic runoff into bodies of water. Some metals are dangerous to health.

Billions of tons of solid waste are discarded on land and in water. Heavy metals (lead, arsenic, cadmium, chromium), Synthetic organic chemicals, include CFCs, found in plastics, pesticides, herbicides, and other products. Ozone shield destruction is associated with CFCs. Other synthetic organic chemicals enter the aquatic food chain where the toxins become more concentrated.

BIODIVERSITY

Biodiversity is the variety of life on Earth. The five major causes of biodiversity loss and extinction are, habitat loss, introduction of alien species, pollution, overexploitation of plant and animals, and disease.
There are 2 values of biodiversity: direct and indirect.

Direct values are medicinal value(medicines), agricultural value(crops, biological pest controls and animals pollinators), and consumptive use values(food production).

Indirect values are waste disposal, freshwater provision through the water biogeochemical cycle, prevention of soil erosion, function of biogeochemical cycles, climate regulation, and ecotourism(human enjoyment of a beautiful ecosystem).

WORKING TOWARD A SUSTAINABLE SOCIETY

Here in the illustration* are things not to do to attain a sustainable society.

A sustainable society would use only renewable energy sources, would reuse heat and waste materials, and would recycle almost everything. It would also provide the same goods and services presently provided and would preserve biodiversity.

*http://highered.mcgraw-hill.com/classware/selfstudy.do?isbn=0072986867