APES Ch. 3-4

Nutrient Cycles (Biogeochemical cycles)

(life-earth-cycles). The elements and compounds that make nutrients constantly move through the air,water,soil,rock, and living organisms within ecosystems as well as the biosphere in cycles. (In keeping with chemical cycling - principle of sustainability). Cycles are driven directly and indirectly by solar energy and earths gravity.

3 Misconceptions of Evolution through Natural Selection

1. "Survival of the fittest" = "Survival of the strongest" NOT true. It means the fittest individuals = those who leave mose descendants. 2. Organisms develop certain traits because they need them. NOT true. It develops an advantage over other organisms which were inherited and their populations grew and continued to evolve this way. 3. Evolution by natural selection involves some grand plan of nature in which species become more perfectly adapted. NOT true. No plan or goal for genetic perfection.

3 Possible Futures for Species when Environments change

1. Adapt - through natural selection 2. Move - to an area with favorable condition 3. Become extinct

Steps in Biological Evolution

1. Genetic Variability 2. Natural Selection

How Sulfur enters the atmosphere

1. Hydrogen sulfide: colorless, poisonous gas with a rotten egg smell. It's released from active volcanoes and from organic matter broken down by anaerobic decomposers in flooded swamps, bogs, and tidal flats. 2. Sulfur dioxide: a colorless and suffocating gas. Comes from volcanoes. Particles of sulfate salts (ammonium sulfate) enter the atmosphere from sea spray, dust storms, and forest fires. Plant roots absorb sulfate ions and incorporate the sulfur as an essential component of many proteins.

Lack of Phosphorus

1. Most soils contain little phosphate, the lack of it often limits plant growth on land unless phosphorus is applied to the soil as a fertilizer (phosphate slats mined from the earth). 2. Also limits the growth of producer populations in many freshwater streams and lakes because phosphate salts are only slightly soluble in water and thus do not release many phosphate ions that producers need as nutrients.

Human Impacts on the Phosphorus Cycle

1. Removing large amounts of phosphate from the earth to make fertilizer and reducing phosphate from the tropical soils by clearing forests. 2. Phosphate rich runoff from land can produce huge populations of algae which can upset the chemical cycling and other processes in lakes (topsoil that's eroded from fertilized crop fields, lawns, and golf courses carries large quantities of phosphate ions into streams, lakes and oceans).

4 Components of Biodiversity

1. Species Diversity 2. Genetic Diversity 3. Ecosystem Diversity (the storehouse) 4. Functional Diversity

Human Impacts on Carbon Cycle

1. We have extracted and burned large amounts of fossil fuels that took millions of years to form (why fossil fuels are nonrenewable). 2. Adding large amounts of carbon dioxide to the atmosphere when we burn fossil fuels and clear carbon-absorbing vegetation faster than it can grow back. 3. Increased concentrations of atmospheric CO2 and other greenhouse gasses such as methane (CH4) are likely to warm the atmosphere by enhancing planets greenhouse effect.

Human Impacts on the Hydrologic Cycle

1. Withdraw large quantities of freshwater from streams. lakes, and aquifers sometimes at rates faster than nature can replace it. Result: some aquifers are being depleted and some rivers no longer flow to the ocean. 2. Clear vegetation for agriculture, mining, road building and other activities. Cover much of the land with buildings, concrete, and asphalt. Result: increases runoff and reduces infiltration that would normally recharge groundwater supplies. 3. Drain and fill wetlands for farming and urban development. Result: interferes with the flood control provided by the wetlands that act like sponges to absorb and hold overflows of the water from heavy rains and melting snow.

Species

A set of individuals that can mate and produce fertile offspring.

Genetic Resistance

Ability of an organism in a population to tolerate a chemical designed to kill a population.

Nitrofication

Ammonia not taken up by plants. Specialized soil bacteria convert most of the ammonia (NH3) and ammonium ion (NH4+) in the soil to nitrate ions (NO3-) which are easily taken up by the roots of plants. The plants then use these forms of nitrogen to produce various amino acids, proteins, nucleic acids, and vitamins. Animals that eat these plants consume these nitrogen-containing compounds (as do detritus feeders and decomposers).

Adaptation/ Adaptive trait

Any heritable trait that improves the ability of an individual organism to survive and produce at a higher rate than others under current environmental conditions.

Reservoirs

As nutrients move through their biogeochemical cycles, the nutrients accumulate in certain portions of the cycles and remain their for different periods of time. EX: atmosphere, oceans, and other bodies of water

Carbon Cycle

Based on carbon dioxide (CO2) gas. CO2 and water vapor (in the water cycle), are key components of the atmosphere's thermostat. If the carbon cycles removes too much CO2 from the atmosphere, the atmosphere will cool. If it generates too much CO2, the atmosphere will get warmer. Slight changes in the cycle (natural or human) can affect the earth's climate and determine the types of life that can exist in various places.

Ch. 4

Biodiversity and Evolution

Extinction

Biological extinction: Process in which an entire species ceases to exist Local extinction: population of a species becomes extinct over a large region, but not globally.

Generalist Species

Broad niches. Can live in many different places, eat variety of foods, and often tolerate a wide range of environmental conditions. Ex: Flies, cockroaches, mice, rates, and humans.

Aerobic Respiration (carbon cycle)

Cells in oxygen-consuming producers, consumers, and decomposers break down glucose and other complex organic compounds to produce CO2 in the atmosphere and water for reuse by producers.

Hydrologic Cycle (water cycle)

Collects, purifies, and distributes the earth's fixed supply of water. Powered by energy from the sun. 3 major processes: 1. Evaporation: solar energy causes water from oceans, lakes, rivers, and soil to evaporate. Liquid water → water vapor in atmosphere. 2. Precipitation: gravity draws the water vapor back down to earth's surface as precipitation (rain, snow, sleet, and dew). 3. Transpiration: water that evaporates from the surfaces of plants and soil (about 90% of the water that reaches the atmosphere).

Phosphorous Cycle

Compounds of phosphorus circulate through water, the earth's crust, and living organisms. Most of these compounds contain phosphate ions (PO4^3-) which serve as an important nutrient. Phosphate cycle does not include the atmosphere like the other cycles. Major reservoir for phosphorus is phosphate salts containing PO4^3- in terrestrial rock formations and ocean bottom sediments. Process: Water runs over exposed rocks and it slowly erodes away inorganic compounds that contain phosphate ions. Running water carries these phosphate ions into the soil where they can be absorbed by the roots of plants and by other producers Phosphate compounds are also transferred by food webs from producers to consumers etc.. Phosphates are a component of biologically important molecules like nucleic acids and energy transfer molecules (ADP and ATP). Also major component of vertebrate bones and teeth.

Human Impacts of Nitrogen Cycle

Human activities have more than doubled the release of nitrogen from the land into the rest of the environment (mostly from the increased use of inorganic fertilizers to grow crops) and the amount released is projected to double again by 2050. This contributes to pollution.

Types of Cycles

Hydrologic (water), carbon, nitrogen, phosphorus, and sulfur cycles. Driven directly and indirectly by solar energy and earths gravity.

Oxygen-deficient environments

In flooded soils, freshwater wetlands, and tidal flats, specialized bacteria convert sulfate ions to sulfide ions. The sulfide ions can then react with metal ions to form insoluble metallic sulfides, which are deposited as rock or metal ores (often extracted by mining and converted to various metals), and the cycle continues.

Human role in Speciation

Learned to shuffle genes from one species to another through artificial selection and through genetic engineering.

Fossils

Mineralized or petrified replicas of skeletons, bones, teeth, shells, leaves, and seeds, or impressions of such items found in rocks.

Reproductive isolation

Mutation and change by natural selection operate independently in the gene pools of geographically isolated populations.

Mutagens

Mutations that occur from exposure to external agents such as radioactivity and natural or human made chemicals.

Heritable traits

New genetic trait that's passed down (developing genetic variability)

Nitrogen Cycle: Bacteria in Action

Nitrogen cannot be absorbed as a nutrient by multicellular plants of animals. There are 2 natural processes that convert (or fix) nitrogen (N2) into compounds that can be used as nutrients. 1. Electrical Discharges (lightning): taking place in atmosphere 2. Takes place in aquatic systems, soil, and roots of some plants where nitrogen-fixing bacteria complete this conversion as part of the nitrogen cycle.

Specialist Species

Occupy narrow niches. Able to live in only one type of habitat, use just one or a few types of food, or tolerate a narrow range of climatic and other environmental conditions. Ex: Some shorebirds, coral (GBR)

Geographic isolation

Occurs when different groups of the same population of a species become physically isolated from one another for a long period of time. For instance, part of a population may migrate in search of food and then begin living as a separate population in another area with different environmental condition. OR by a physical barrier (mountain range, stream, or road), a volcanic eruption, tectonic plate movements, or wind or flowing water that carry few individuals to a distant area.

Carbon-Containing Fossil Fuels

Over millions of years. buried deposits of dead plant matter and bacteria are compressed between layers of sediment, where high pressure and heat convert them to carbon-containing fossil fuels (coal, oil, and natural gas) which are not released into atmosphere until they are extracted and burned.

Habitat

Place where species live.

Wastes and Cast-off Particles

Plants and animals return nitrogen-rich organic compounds to the environment as wastes and cast off particles of tissues (leaves, skin, or hair). Also through their bodies when they die and are decomposed or eaten.

Surface Runoff

Precipitation falling on terrestrial ecosystems which flows into streams that lead to oceans and rivers, repeating the cycle. Or, the precipitation is absorbed by the soil and used by the plants or is evaporated by the soil itself.

Aquifers

Precipitation that sinks through soil and permeable rock formations to underground layers of rock, sand, and gravel and is stored as groundwater.

Glaciers

Precipitation that's converted to ice and stored for a long time.

Speciation

Process in which one species splits into two or more different species. For sexually reproducing organisms, a new species forms when one population of a species has evolved to the point where its members can no longer breed and produce fertile offspring with members of another population that did not change or that evolved differently. Common way speciation occurs is when a barrier or distant migration separates two or more populations of a species and prevents the flow of genes between them. Happens in 2 phases: 1. Geographic isolation 2. Reproductive Isolation

Evolution

Process whereby earth's life changes over time through changes in the genes of populations of organisms in succeeding (future) generations.

Photosynthesis (carbon cycle)

Producers remove CO2 from the atmosphere, and aquatic producers remove it from the waters. Use photosynthesis to convert CO2 into complex carbohydrates such as glucose.

Mutations

Random changes in the DNA that can be inherited by offspring ONLY if the mutations occur in the reproductive cell (only way to inherit the mutation), although they can occur in any cell.

Decomposers

Release the carbon stored in the bodies of dead organisms on land back into the air as CO2. In water, they release carbon that can be stored as insoluble carbonates in bottom sediment. Marine sediments are the earth's largest store of carbon.

Human Impacts of the Sulfur Cycle

Releasing large amounts of sulfur dioxide into the atmosphere by three ways: 1. Burn sulfur-containing coal and oil to produce electric power. 2. Refine sulfur-containing oil (petroleum) to make gasoline, heating oil, and other useful products. 3. Extract metals such as copper, lead, zinc, from sulfur-containing compounds in rocks that are mined for these metals. Sulfur dioxide (SO2) → droplets of sulfuric acid (H2SO4) and particles of sulfate (SO4^2-) which return to the earth as acid deposition, which can damage ecosystems.

Theory of Evolution by Natural Selection

Scientific explanation of how the process of evolution takes place.

Mass Extinction

Significant rise in extinction rates above the background level. (about 25-95%)

Nitrogen Fixation

Specialized bacteria in soil as well as blue green algae (cyanobacteria) in aquatic environments combine gaseous nitrogen (N2) with hydrogen to make ammonia (NH3). The bacteria use some of the ammonia they produce as a nutrient and excrete the rest into the soil or water. Some ammonia→ammonium ions that plants use as nutrients.

Dentrification

Specialized bacteria in waterlogged soil and in the bottom sediments of lakes, oceans, swamps, and bogs convert NH3 and NH4+ back into nitrate ions, and then into nitrogen gas (N2) and nitrous oxide gas (N2O) which are released into the atmosphere to begin the nitrogen cycle again.

Ammonification

Specialized decomposer bacteria convert this detritus into simpler nitrogen-containing inorganic compounds such as ammonia (NH3) and water soluble salts containing ammonium ions (NH4+).

Background Extinction

Species have disappeared at a low rate. (About 0.0001% of species per year) = 1 per million years.

Endemic Species

Species that are found in only one area. They are especially vulnerable to extinction because unable to migrate or adapt in rapidly changing environments. Exist on islands and other unique areas (tropical rainforests).

The Sulfur Cycle

Sulfur circulates through the biosphere. Earth's sulfur is stored underground in rocks and minerals and in the form of sulfate salts buried deep under ocean sediments.

Species Diversity

The number and variety o the species present in any biological community.

Ecological Niche or Niche

The role that a species plays in its ecosystem. Species way of life in a community and includes everything that effects its survival and reproduction, such as how much water and sunlight it needs, how much space it requires, what it feeds on, what feed on it, and the temp. and other conditions it can tolerate (pattern of living).

Biomes

The terrestrial (land) portion of the biosphere that have been broken up into large regions such as forests, deserts, and grasslands with distinct climates and certain species (especially vegetation) adapted to them.

Ecosystem Diversity

The variety of earth's deserts, grasslands, forests, mountains, oceans, lakes, rivers, and wetlands. Each of these ecosystems is a storehouse for species and genetic diversity.

Functional Diversity

The variety of processes (like energy flow and matter cycling) that occur within ecosystems as species interact with one another in food chains and webs.

Biodiversity

The variety of the earth's species, the genes they contain, the ecosystem in which they live, and the ecosystem processes such as energy flow and nutrient cycling that sustain all life.

Genetic Diversity

Variety of genes found in a population or in a species.

What Biodiversity Does

Vital part of the natural capital that helps keeps us alive and supports our economies. Biodiversity: -Provides us with food, wood, fibers, energy from wood and biofuels, and medicines. - Preserves the quality of the air and water, maintains the fertility of topsoil, decomposes and recycles waste, and controls the populations of species (that we call pests).

Genetic Variability

variety in genetic makeup of individuals in a population that occurs during mutations.