Transcript The Nature of Science

Population Dynamics
SC.912.L.17.5
Analyze how population
size is determined by
births, deaths,
immigration, emigration,
and limiting factors
(biotic and abiotic) that
determine carrying
capacity.
Source: http://www.stephsnature.com
What do I need to know?
 how population size is determined by
births, deaths, immigration, emigration
and limiting factors
 use data about population dynamics,
abiotic factors, and biotic factors to
explain a change in carrying capacity and
population size in an ecosystem
 that different types of organisms exist
within aquatic systems due to chemistry,
geography, light, depth, salinity, and/or
temperature
 the potential changes in an ecosystem
resulting from seasonal variations,
climate changes and/or succession
 the positive or negative consequences
that result from a reduction in biodiversity
Population Size
 the size of a
population is always
changing
 four factors affect size
immigration
births
emigration
deaths
Population Growth:
Based on Available Resources
 Exponential Growth
 rapid population
increase due to an
abundance of
resources
 Logistic Growth
 population facing
limited resources
Abiotic vs. Biotic
non-living
living
Limiting Factors
Video Guiding Questions:
1. Explain the biological
carrying capacity?
2. What variables
(limiting factors) affect
the carrying capacity
of a population?
3. How can biologists
manage a population
such as sturgeon?
Carrying Capacity
 the maximum number
of individuals in a
population that the
environment can
support
Aquatic Systems
 factors affecting
organism distribution
 geography
 light
 depth
 salinity
 temperature
Source: http://sky.scnu.edu.cn/life/class/ecology/chapter/Chapter3.htm
Ecological Relationships
Competition, Predation & Symbiosis
Video Guiding Questions:
1. Define competition,
predation and
symbiosis.
2. Explain the
ecological niche (role)
of organisms.
Changes in Ecosystems
Succession
Changes in Ecosystems
Climate Change
Source: http://www.intechopen.com
Loss of Biodiversity
Video Guiding Questions:
1. Define biodiversity.
2. Describe the web of
life.
3. How do human
activities cause a loss
of biodiversity?
Show What You Know
The number of pythons found throughout Everglades
National Park has increased in recent years. These
huge snakes are not native to Florida and are believed
to have been released into the wild by pet owners.
Wildlife biologists have initiated attempts to capture
and remove these pythons. Which statement best
explains the biologists’ reason for removing these
pythons from the Everglades?
A. The pythons could upset the territorial
boundaries of native organisms.
B. The pythons could adapt to overcome diseases
common to native snakes.
C. The pythons could prey on native organisms and
cause native populations to decline.
D. The pythons could begin to interbreed with
native snakes and produce a more successful
species.
Show What You Know
The graph below shows a population of pigeons living in a
neighborhood over a ten-year period.
Which of the following statements account for the change in
population seen between years 7 and 8?
A. The birth rate of the pigeons increased.
B. The emigration rate of the pigeons decreased.
C. The death rate of the pigeons exceeded the birth rate.
D. The neighborhood reached its carrying capacity for the
pigeon population
Show What You Know
A new species of snake was introduced to a tropical region.
Scientists then noticed a steady decline in the presence of field
mice and an increase in the number of snakes. Which of these
is the most likely explanation about why the population size of
each animal changed?
A. The snakes introduced to the region dominated the
habitat, forcing the mice to find another place to live.
B. The mice became prey to the introduced snakes,
allowing the snake population to increase but
decreasing the mice population.
C. The snakes introduced to the region competed with the
mice for food, allowing the snake population to
increase but decreasing the mice population.
D. The people in the surrounding area set traps that killed
the mice, allowing the snakes to live without any
predators and therefore to increase in number.
Show What You Know
The highest concentration of life
exists in the top 200 meters of ocean
water. What is the most important
factor that influences the
concentration of life?
A. amount of gases at the surface
B. amount of nutrients in the water
C. large number of predators at
lower depths
D. amount of sunlight
Show What You Know
Rabbits introduced into Australia over 100 years
ago have become a serious pest to farmers.
Rabbit populations increases so much that they
displaced many native species of plant eaters.
What is the most logical explanation for their
increased numbers?
A. Rabbits have a high death rate.
B. There are few effective predators.
C. Additional rabbit species have been
introduced.
D. There is an increase in rabbit
competitors.
Show What You Know
Scientists found, that over a period of 200 years, a
mountain pond was transformed into a meadow.
During that time, several communities of organisms
were replaced by different communities. Which of
these best explains why new communities were able
to replace older communities?
A. The original species became extinct.
B. Species in the older community died from old
age.
C. The abiotic characteristics of the habitat
changed.
D. Diseases that killed the older organisms
disappeared.