Biodiversity and
Evolution
UNIT 1: MODULE 3
Francis Nathan Acosta
IN THIS MODULE YOU ARE EXPECTED TO:
1.Relate species extinction to the failure of population of organism to adapt to
abrupt changes in the environment and;
-Explain the importance of biological diversity
-Find out how changes in the environment can affect species extinction
-Distinguish environmental changes that may result in the loss of the species
2.Make a multimedia presentation of an timeline of extinction of representative
micro organism, plant and animals.
POPULATION
Is a group of living things within a
certain area that are all of the same
species
Pertains to the number of organisms of
the same species living in a certain
place
A population of one kind may affect a
population of another kind within the
community
COMMUNITIES
Several different populations may be
found in the community
Communities with many different
species (A high index of diversity) will
be able to withstand environmental
changes better tan communities with
only a few species (A low index of
Diversity).
WHAT HAPPENS TO COMMUNITY WHEN ITS
SPECIES DIVERSITY IS REDUCED?
The overall biodiversity loss can speed up extinction, more
and more animals and plants are facing an uncertain future
Loss of biodiversity undermines the ability of ecosystems
to function effectively and efficiently.
BIODIVERSITY
Refers to the variety of life in the area
Ex. Animals, plants, fungi, and bacterias
This changes overtime as extinction occurs and
new species evolve
Examples
PLANTS ANIMALS FUNGI
IMPORTANCE OF BIODIVERSITY
Biodiversity is essential for the processes that support all life on
earth, including humans.
Without a wide range of animals, plants and micro organisms,
we cannot have the healthy ecosystems we rely on to provide
us with the air we breathe and the food we eat
It plays a major role in maintaining the balance of the earth,
everything depends upon the biological diversity of different
plants and animals.
DENSITY
Population can be of the same size, When we
consider the number of individuals per unit area,
we are referring to the density of the population
DENSITY
Differences in population density in any community
may be attributed to many factors when:
-New members move into the ecosystem
-Members move out of the ecosystem and
-Birth and Death rates in the ecosystem
LIMITING FACTORS
Anything that limits the size of a population like
certain environmental condition
This keep a population from increasing in size and
help balance an ecosystem
Examples
FOOD WATER LIGHT
Examples
TEMPERATURE SOIL NUTRIENTS LIVING NUTRIENTS
HOW ARE LIMITING FACTORS RELATED TO
DENSITY?
Density is a dependent limiting factor that causes a
population’s per capita growth rate to change typically to
drop with increasing population density.
HOW ARE LIMITING FACTORS RELATED TO
DENSITY?
The numerous types of density dependent limiting factors
include availability of food, predation, disease, and
migration. But the predominant factor is the availability of
food
CARRYING CAPACITY
Maximum population size an environment can
support
If the population size rises above the carrying
capacity, organisms die because not all their needs
can be met
These are affected by changes in the environment
ENDANGERED
When a specie population become so
low that only a few remain, the species
are considered ENDANGERED and will
possibly become extinct.
Ex. Tamaraw in Mindoro, Mouse deer in
Palawan, Philippine deer, Monkey-eating
eagle, Dugong in negros, Batangas and
Leyte are in danger of extinction.
Examples
TAMARAW DUGONG MOUSE DEER
THREATENED
There is a particular species that decline
so fast that is becomes endangered and
is said to be THREATENED.
An endangered species is any species
that is at risk of extinction because of a
rapid decrease in its population or a loss
of its critical habitat.
Examples
KOALA RHINO TARSIER
EXTINCT
Is the disappearance of a species when
the last of its member die, changes to
habitat can threaten organism with
extinction
As population of people increase, the
impact of their growth and development
is altering the face of the earth and
pushing many other species to the brink
of extinction
Examples
SABER TOOTH DODO BIRD TASMANIAN
TIGER TIGER
WHAT CAUSES SPECIES
EXTINCTION?
Habitat loss is the primary cause of higher extinction rates.
Over exploitation of wildlife for commercial purposes, the
introduction of harmful nonnative species, pollution, and
the spread of diseases
THANK
You
