All living organisms are limited by factors in the environment

All living organisms are limited by factors in the environment

Monday, October 30 POPULATION ECOLOGY

Monday, October 30 POPULATION ECOLOGY

Population Definition Root of the word: The word in another language from Latin populus, meaning people ILLUSTRATE Use in a sentence

All living organisms are limited by factors in their environment. Population is a group of individuals of the same type (or species) Species is a group of organisms that can interbreed and produce fertile offspring

Population growth = an increase in the size of a population over time Birth rate greater than death rate population grows Birth rate equals death rate population stays the same Death rate greater than birthrate population shrinks

Factors that change population size: 1.immigration movement of individuals into a population from another population 2. births causes an increase in population size 3. emigration movement of individuals out of a population and into another population 4. deaths causes a decrease in population size

BIRTH DEATH IMMIGRATION EMIGRATION

Work with your group to write 1 question about Migration (level 3 question) Level 3 words include: APPLY BUILD CHOOSE CONSTRUCT DEMONSTRATE DEVELOP DRAW EXPERIMENT ILLUSTRATE PLAN MAKE USE OF MODEL ORGANIZE SELECT SOLVE UTILIZE

Under ideal conditions with unlimited resources, a population will grow exponentially. Exponential growth = as a population gets larger, it grows faster J curve

EXPONENTIAL GROWTH CURVE Population growth is NOT limited Takes on an J-shape Ideal and doesn t normally occur in most populations What kinds of organisms might have exponential growth and why? Bacteria grown in a lab: Unlimited nutrients and no predators!

Work with your group to write 1 question about Exponential Growth (level 3 question) Level 3 words include: APPLY BUILD CHOOSE CONSTRUCT DEMONSTRATE DEVELOP DRAW EXPERIMENT ILLUSTRATE PLAN MAKE USE OF MODEL ORGANIZE SELECT SOLVE UTILIZE

Limiting factor = Any biotic or abiotic factor that restricts the numbers of organisms Examples: food, water, shelter, etc Two types of Limiting Factors: 1. density-dependent 2. density-independent

1. Density-dependent limiting factors - affected by the number of individuals in a given area competition and the availability of food, water and space predation parasitism and disease Predation occurs more frequently and disease spreads faster because the population is dense.

2. Density-independent limiting factors - limit a population s growth regardless of the density of the population unusual weather natural disasters human activities (pollution)

Work with your group to write 1 question about Limiting Factors (level 3 question) Level 3 words include: APPLY BUILD CHOOSE CONSTRUCT DEMONSTRATE DEVELOP DRAW EXPERIMENT ILLUSTRATE PLAN MAKE USE OF MODEL ORGANIZE SELECT SOLVE UTILIZE

CARRYING CAPACITY The maximum number of individuals that can be supported by the ecosystem. The limit is determined by the availability of resources and by their interactions with other organisms.

LOGISTIC GROWTH CURVE: Occurs when population growth is limited by factors in the environment S curve As resources become less available, the growth of the population slows or stops. carrying capacity Population reaches carrying capacity

J-CURVE VS. S - CURVE All populations will eventually display an S-curve.

Human Population Growth!

Population graphs usually aren t exactly S curves there may be some wiggle around the carrying capacity

Work with your group to write 2 questions about Carrying Capacity (level 4 question) Level 2 words include: ANALYZE CATEGORIZE CLASSIFY DISCOVER DIVIDE EXAMINE GROUP INSPECT SEQUENCE SIMPLIFY DISTINGUISH DISTINCTION RELATIONSHIPS FUNCTION ASSUME CONCLUDE

HOMEWORK Answer questions about graph on the bottom of the back page (Do this NOW) Write a sentence summary of today s notes Make sure all your questions are written! (3 on the front, 2 on the back, appropriate levels (3 or 4)).