Download Living things and the environment

LIVING THINGS AND
THE ENVIRONMENT
Chapter 12
Goodman’s Mouse Lemur
Golden Brown Mouse Lemur
Grey Mouse Lemur
What does an Organism get from its
Environment?
• What is an organism?
• They live in different types of surroundings or environments.
• From their environment they get:
Food
Live
Water
to
Grow
Shelter
Reproduce
Other things
• An environment that provides
these things is called a habitat.
What are two parts of an Organisms Habitat?
•An organism interacts with both living and
non-living parts of its habitat.
• Biotic factors
• Abiotic factors
How is an Ecosystem Organized?
• Most organisms live together in populations and communities that
interact with abiotic factors within their ecosystem.
Organisms
•Species – a group of organisms that can mate with
each other and produce offspring that can also mate
and reproduce.
Populations
•All members of one species living in a particular area.
Communities
•A particular area that contains more than one species
of organisms.
Ecosystem
•The community of organisms that live in a particular
area along with their non-living environment.
• Ecology – the study of how organisms interact with
each other and with their environment.
POPULATIONS
How do Populations Change in Size?
• Populations can change in size when new members join the
population or when members leave the population.
• Most common ways:
• Birth rate
• Death rate
If the birth rate > death rate, population size increases.
If the death rate > birth rate, population size decreases.
Losing Friends
• Indiana bats eat pests that bother both people and crops.
These bats hibernate in large groups during the winter in a few
caves in the Midwest. What does the graph show you about
the bat population in recent years?
Immigration & Emmigration
• The size of a population can also change when individuals move
into or out of the population.
• Immigration – moving into a population
• Emmigration – leaving a population
• Example:
Changes in a Rabbit Population
• This graph shows how the size of a rabbit population changed
over ten years.
What Factors Limit Population Growth?
• Limiting Factor – an environmental factor that causes a population
to stop growing or decrease in size.
• Four examples of limiting factors
1.
2.
3.
4.
Climate/weather
Space
Food
Water
Climate/Weather
• Changes in climate conditions, such as temperature and the
amount of rainfall, can place severe limits on the growth of a
population.
• Examples:
Space
• Examples:
• Gannets
• Plants
Food & Water
• Organisms require food and water to survive.
• When food and water are in limited supply, they can be limiting
factors.
• Example:
• Carrying capacity – the largest population that an area can support.
INTERACTIONS
AMONG LIVING
THINGS
How Do Adaptations Help an Organism Survive?
• Natural Selection
• Individuals unique characteristics are well-suited for an environment tend
to survive and produce more offspring.
• Offspring inherit these characteristics also live to reproduce.
• Poorly suited characteristics may disappear from a species.
• Adaptations
• The result of natural selection
• The behaviors and physical characteristics that allow an organism to live
successfully in their environments.
• If a species cannot adapt to changes in its environment, the entire species
can disappear from Earth and become extinct.
• Example: Arctic hare
How Do Adaptations Help an Organism Survive?
• Niche – A specific role of an organism in its habitat.
• Included in a niche:
• What type of food the organism eats
• How it obtains this food
• What other organisms eat it
• How and when the organism reproduces
• The physical conditions it requires to survive
• Every organism has a variety of adaptations that are suited to
its specific living conditions and help it survive.
Types of Interactions
• Competition – the struggle between organisms to survive as
they attempt to use the same limited resources.
• Examples:
• flycatcher and elf owl
• Weeds in a garden
• In an ecosystem, there are limited amounts of
food, water, and shelter.
• Organisms that share the same habitat often
have adaptations that enable them to reduce
competition.
Types of Interactions
• Predation – an interaction in which one organism kills another
for food of nutrients.
• Predator
• Prey
• Effects on the population size
• Too many predators often result in a decrease in the size of
the prey population.
• A decrease in the number of prey often results in less food for
predators, which can cause the predator population to
decline.
Predator-Prey Interactions
• What variable is plotted on the
horizontal axis? What two
variables are plotted on the
vertical axis?
• How did the moose population
change between 2002 and 2007?
What happened to the wolf
population from 2003 through
2006?
• How might the change in the
moose population have led to the
change in the wolf population?
• What adaptations does a wolf
have that make it a successful
predator?
• How might disease in the wolf
population one year affect the
moose population the next year?
On Isle Royale, an island in Lake
Superior, the populations of wolves (the
predator) and moose (the prey) rise and
fall in cycles.
Types of interactions
• Symbiosis – any relationship in which two species live closely
together and at least one of the species benefits.
• Three main types of symbiotic relationships:
• Mutualism – a relationship in which both species benefit.
• Example
• Commensalism – a relationship in which one species benefits and
the other species is neither helped nor harmed.
• Example
• Parasitism – a relationship that involves one organism living with,
one, or inside another organism and is harming it.
• Example
CHANGES IN
COMMUNITIES
How Do Primary and Secondary Succession
Differ?
• Succession – the series of predictable changes that occur in a
community over time.
• Primary succession – the series of changes that occurs in an
area where no soil or organisms exist.
• Example:
• Pioneer species – the first species to populate
an area.
• Example:
How Do Primary and Secondary Succession
Differ?
• Secondary Succession – the series of changes that occurs in an area
where the ecosystem has been disturbed, but where soil and
organisms still exist.
• Example:
• Unlike primary succession, secondary succession occurs in a place
where an ecosystem currently exists.
• Occurs more rapidly because the soil already exists and seeds from
some plants remain in the soil.
Comparison of Primary and Secondary Succession
Based on the information given, what facts would complete this table?