Transcript Document

APES Semester 1 in
review
2014, The
year
everyone
gets a 5!
Who Lives Where and
Why?
Evolutionary response…
Resource Partitioning - Whenever there
is competition for the same resources,
someone loses out!
Evolution
Speciation (Galapagos
Finches)
Geological Context
(space and time for evolution)
•
•
•
•
•
•
Plate tectonics
Geological time scale (fig. 5-21)
Cambrian explosion
Selective breeding
Artificial selection
Natural selection
Island biogeography…. Founder effec
The Green Revolution
• To eliminate hunger by improving crop performance
• Movement to increase yields by using:
–
–
–
–
–
New crop cultivars
Irrigation
Fertilizers
Pesticides
Mechanization
Results:
•
•
•
•
•
Did not eliminate famine
Population still increasing
Increase cost of production
An increased negative environmental impact
Didn’t work for everyone
Chapter 13: Fossil
Fuels
Exxon Valdez, Drilling in ANWR
Coal-several (400) hundred
years
Natural Gas – at least a 50
year supply in the United
States
Oil- Peak Oil passed
More Energy Facts
• We get 50% of our crude oil from foreign
sources
• Alaska pipeline built to help increase
production of domestic crude oil
• Types of coal:
• Peat (not coal)  Lignite (brown coal) 
Bituminous coal (soft coal with high sulfur) 
Anthracite (hard coal with low sulfur)
K- Selected Species
populations of a roughly constant size
have low reproductive rates.
offspring require extensive postnatal care until they have sufficiently matured.
They are very limited in resourses therefore they are a very competitive species.
Elephants, Rhinos and long lived plants are examples of a k-selected species.
R-Selected Species
populations that experience rapid growth of the J-curve variety.
offspring produced are numerous, mature quite rapidly, and require very little
postnatal care.
this population grows fast, reproduces quickly, and dies quickly.
Bacteria and mice are examples of r- selected species.
Carrying capacity
changes…
Carrying Capacity-------------------------------------------------K-species
exponential
r-species
Carrying Capacity
-------------------------------------------------K-species
exponential
r-species
Ch 6 and 7: The Human
Population
Chapter 6
•World population trends
•Calculations
•Demographic transition
•Age structure diagrams
•Developed vs. developing
countries
Chapter 7
•Fertility rates
•World bank
•1994 UN conference in
Cairo- program of action
Population Density
• Population Density (or ecological population
density) is the amount of individuals in a
population per unit habitat area
– Some species exist in high densities - Mice
– Some species exist in low densities - Mountain
lions
• Density depends upon
– social/population structure
– mating relationships
– time of year
Population Dispersion
Population dispersion is the spatial pattern
of distribution
There are three main classifications
Clumped: individuals are
lumped into groups
ex. Flocking birds or
herbivore herds due to
resources that are clumped
or social interactions
most common
http://www.johndarm.clara.net/galleryphots/
Population
Dispersion
Uniform: Individuals are regularly
http://www.calflora.net/bloomingplants/creosotebush2.html
spaced in the environment - ex.
Creosote bush due to antagonism
between individuals, or do to regular
spacing of resources rare because
resources are rarely evenly spaced
Random: Individuals are randomly
dispersed in the environment ex.
Dandelions due to random
distribution of resources in the
environment, and neither positive nor
negative interaction between
individuals rare because these
conditions are rarely met
www.agry.purdue.edu/turf/ tips/2002/clover611.htm
Age Structure
• The age structure of a population is
usually shown graphically
• The population is usually divided up into
prereproductives, reproductives and
postreproductives
• The age structure of a population
dictates whether is will grow, shrink, or
stay the same size
Age Structure Diagrams
Positive Growth
Pyramid Shape
Zero Growth
(ZPG)
Vertical Edges
Negative Growth
Inverted Pyramid
Population Dynamics
Outline
• Characteristics of a Population
• Population Dynamics and
Carrying Capacity
•
•
•
•
Reproductive Strategies
Conservation Biology
Human Impacts
Working with Nature
• Biotic Potential
–factors allow a population to
increase under ideal conditions,
potentially leading to exponential
growth
• Environmental Resistance
–affect the young more than the
elderly in a population, thereby
affecting recruitment (survival to
reproductive age)
(b) crude birth rate= number birth per 1000 individuals
(d) crude death rate= number death per 1000 individuals
(r) growth rate = natural increase in population expressed as percent
per years (If this number is negative, the population is shrinking.)
equation:
rate = birth – death
But other factors affect population growth in a certain area…
Population growth rates
increase population
births

immigration 
decrease population

deaths
 emigration (exit)
r = (birth - death)+ (immigration-emigration)
immigration = migration of individuals into a population
from another area or country
emigration = migration of individuals from a population
bound for another country
r = (birth - death)+ (immigration-emigration)
example: population of 10,000 has
100 births (10 per 1000)
50 deaths (5 per 1000)
10 immigration (1 per 1000)
100 emigration (10 per 1000)
You try.
B
D
I
E
r=( 10/1000) – (5/1000) + (1/1000) – (10/1000)
r=(0.01-0.005) + (0.001 – 0.01)
r = 0.005 – 0.009 = -0.004 or –0.4% per year
Know Rule of 70
If the growth rate is 1% and the population size is
10,000, how many years will it take to get to a
population of 40,000?
Population doubling:
70/rate =70/1% =70 years to double
In 70 years the population will be 20,000
1 D.T.  20,000
2 D.T.  40,000
(70 years)(2) =140 years
In 140 years, the population will be 40,000 people.
SHOW YOUR WORK!!!!!!!!!
Bottom Line= as countries develop, first their death rate
drops and then their birth rate drops
Reasons for the phases:
Phase II:
 medical care
 nutrition
(births still high)
 technology
Phase III:
 birth control
 education (of women)
 lower mortality rate of infants
 less child labor
Developed Countries
 Canada, U.S., Australia, Western Europe
(Denmark)
Developing Countries
 Latin America, China, Africa (Kenya)
 1/5 of the world’s pop. Lives in absolute
poverty, illiterate, lack clean H2O and don’t
have enough food
 80% of world’s pop. Lives in developing co.
and growing
• Total fertility= avg. # of children born per
woman
• For developed countries = 2.1
• For developing countries = 2.6
• Fertility of 2.0= replacement level
– Under 2.0 = shrinking population
– Over 2.0 = growing pop.
• For developed countries = 2.1
• For developing countries = 2.6(or higher)
• Special agency of the United Nations
• Receives $$ from developed co. and loans $$ to
developing co.
– Sometimes this backfires by increasing debt
• Oversees all types of issues, not just environmental issues
– Ex. electricity, roads, new modern technology
Toxicology
• Extrapolation from animal to human
•
•
•
•
17 June 2010
Usually physiology of other mammals is like
humans, so rats, mice, dogs, cats, etc. make good
surrogates.
But, CATS CAN NOT take Tylenol, Aspirin;
DOGS can not take chocolate.
Then, what can experimental animals
tolerate that humans can't ??
EnvHealth&Tox.ppt
33
Toxicology
• Expense of laboratory studies
– Drug approval by Food & Drug
Administration (FDA) takes years, $$.
• Safety of medicines
• Effectiveness of medicines
– Studies of environmental chemicals, biological
agents also takes time & money.
17 June 2010
EnvHealth&Tox.ppt
34
•Other factors:
Toxicology
–Bioaccumulation:
increased concentration
in specific tissues over
time.
–Biomagnification:
increased concentration
up a food web.
17 June 2010
EnvHealth&Tox.ppt
35
How Much Exposure to a Particular
Toxic Chemical Causes a Harmful
Response?
50 %
Method:
Measure chemical’s median
lethal dose (LD50); the
amount received in one dose
that kills 50% of the
organisms (usually rats or
mice) in a test population
within a 14 day period.
Threshold Level
0.0001
0.001
0.1
Dose mg/kg
1.0
Biomagnification

Biomagnification- the
increase in a chemical
concentration in
animal tissues as the
chemical moves up
the food chain.
Persistence

Persistence- how long a chemical remains in the
environment
Risk Analysis