NSCI 115

• 1. Some see only economic
• 2. Some
• 3. Some

• 1. Renewable VS. Non-Renewable
• 2. Reserves

• Depends on rates of formations and usage
• *get energy from coal and gas, coal and natural gas is nonrenewable
• *will use up coal and gas faster than it is forming
• -some resources depend on how we use it and can go both ways

Ex: water, hydro-electric is renewable

• Located resources that can be profitable extracted
• *only when you can drill extract and money
• EX: oil

• 1. Reduce: efficiency improvements
• 2. Reuse & Recycle: repeated usage in one form or another
• -plastic made from petroleum
• 3. Substitution: one resources used in place of another

Study of size, growth, distribution, & characteristics of human population

• - 6.6 billion peoplein the world
• - population levels affect resource use and pollution/waste

• 1. Resource depletion
• 2. Pollution

natural population exhibit an S-shaped curve

• 1. Lag phase: slow growth
• 2. Exponential phase: increasingly rapid growth
• 3. growth slows down and levels out or slightly decreases

• maximum popultion size that can be sustained by an environment for a "long time"
• --some animals go extinct

• We dont know.
• --estimates carry widely - vary by orders of magnitude

• Passing carrying capacity may lead to population crash by disease, famine, drought, etc.
• --can happen locally or globally
• --is being modified by tech through doctors and nurses, etc.

From ~125,000 human ancestors (~1Ma) to 5-10 million (by ~8000BCE)

Went from hunter to gather to agricultural revolution

Increase attributed to tool use, migration, use of fire

During American immigration

Agricutural (Neolithic) Revolution (start of expontential growth)

Spread of agriculture & demestication 8,000-5,000 years ago

By AD 1: ~ 300 million people

Cheap advances in mass production, germ theory, good improvements

by AD 1800: ~1 billion people

Agricultural Industrialization

Farm

Not evenly distributed and changes over time

Growth Rate: expressed as % annual growth

# of children a woman will have on average during her child bearing years

~2.1 is replacement level

• North America
• Europe
• Japan
• Australia
• Former Soviet Union

• South America
• Africa
• Rest of Asia

Uniform age profile: about same 3 of people in each age group until 50's

Profile is strongly skewed toward younger age groups

Even if TFR drops to replacement level, population will continue to grow

2002 resembles LDC profiles, 2050 projections resembles MDC profiles

Population will continue to increase until TFR is below replacement level AND world age profile is no longer skewed

Consequences? Population is a factor of the impace we have on the plant

~300 million people (4.6 % of the world's population)

TFR~ 2.08 & MDC profile, but not population is still growing due to immigration

Has very high per capita consumption

Population skewed towards Baby Boomers (dont count on social security)

• Education
• Contraceptive use
• Family Planning
• Moral Restraint
• Economic Incentives
• Government Regulations

They want a boy first, if girl then the child is either abandoned or given up

Population have inherent variability

Traits (expression of genes) might provide advantages and disadvantages for survival and reproduction

Heredity provides a pathway for favorable traits to be passed on

Repeat several million times

May be local, regional, or global

Can lose a habitat in one place but is somehwere else would be protected

Some events are horrific, sheer luck might be the best survival traits (astro hit earth, small reptile with slow metabolism survived, big water reptile didnt but small fishes did

• Environmental
• Catastrophic
• Man-Made

Might have advantages over specialists

Have narrow range under conditions, depend on habitat, and if they depend only on one food and there is no more there are problems

It opens up the niches for the radiation of survivng groups

• Habitat disruption
• Fragmentation
• Introduced species
• Overhunting

Humans might be 6th Mass Extinction

the variety of living things in an area

can be expressed at genetic level

# of species or other classification level

An increasingly diverse biosphere

Background extinction rate is not so fast (at the rate at which new species evolve)

Mass extinctions causes setbacks in total biodiversity (extinction leads to open niches, survivors multiple in new niches, new species are created

• 1. Precambrain
• 2. Paleozoic Era
• 3. Mesozoic Era
• 4. Cenozoic Era

• 1st Life (Prokaryotes)
• 1st Eukaryotes
• 1st Multicellular Life
• Every life on Earth was soft

Simple organism, single cell, does not have nuclei

Single cell organism, have nucleus

Development of Eukaryotes

• Cambrian explosion of life (1st hard parts)
• 1st vertebrates (fishes)
• Invasion of land (plants, Arthropods - joints appendix with exoskeleton, amphibians)
• 1st seed plant (freedom from water)
• 1st reptiles

• Diversification of reptiles (Dinosaurs, flying reptiles, marine reptiles)
• 1st Mammals
• 1st Birds
• 1st Flowering plants

Diversification of mammals

We are not sure

Ranges from 5 million to 100 million

• 1. Ratios
• 2. Species Area Curves

Count known species, project total based on ratios

• Start counting species
• Project the slowing rate of new discoveries

We live in a time when diversity is at or near its peak

Many scientist are concerned that human impacts are causing extinctions at an unprecedented rate

6th Mass Extinction?

Physical Environment: Lithosphere (land), Hydrosphere (water), Atmosphere (air)

Biological Environment: Biosphere

The flow from one "sphere" to another

Described by biogeochemical cycles

• Ecosystems
• Organisms

Energy from the sun

Study of organism; their relationships to each other & surrounding environment

Group of organisms that interbreed and producce viable offsprings

Group of individuals of the same species living in the same area

Regulation of growth by limiting factors

Growth is controlled by resources in shortest supplies

If control is changed

All of the populations in an area

Community plus its surrounding environment

• 1. Physical Environment: resources avaliability
• 2. Biological Environment: organism interactions
• 3. Niche: how an organism makes its' living

Where an organism lives

• 1. Competition: predator against each other for resources
• 2. Mutualism: both benefit
• 3. Commensalism: helps one and dont harm the other
• 4. Parasitism: helps one, harms the other

Only live in one area & one area only

EX: Verreaux's sifaka: only in Madagascar

When one species comes from another inhabit to invade other species

EX: Starlings from London affects Blue Birds in America

• Central maximum
• Zone of Physiological Stress
• Zone of Intolerance

Sharp boundary between seperate communites

Changes :Follow latitude, Elevation, Water Depth, etc.

Change overtime tracked with succession

Pioneer Community--Intermediate--Climax Community

Relate to amount of energy available to an ecosystem

Rate that producer biomass is formed in a community (photosynthesis)

Energy transfer tracked with food chains & food webs

Study of the Origin of Life

Origin of Life: first evidence of life (3.5Ba) soon after conditions for life were favorable (4.0Ba)

-Miller's & Urey's experiment

Fossil Succession: vertical order of fossils is the same in different places

Concept of extinction

Change through time

Natural Selection

Survival through superior adaptation

Envisioned species arising from natural selection

Adaptation to niche to survive

How traits are passed through herdity (genetics)

• Variability
• Reproduction
• Heredity
• Repeat