This document discusses the causes of species extinction, including deforestation, pollution, habitat destruction, and overpopulation. It defines key terms like biodiversity, extinction, and species. Several human activities are highlighted as contributing to extinction, such as illegal logging, kaingin farming, water pollution from domestic waste and factories, air pollution from vehicles, and destruction of coastal ecosystems through dynamite fishing and development. The greenhouse effect and climate change are also discussed as global issues exacerbating extinction. In summary, the document outlines the biological concepts of extinction and biodiversity before examining various human-caused threats driving increased species loss.

1. BIODIVERSITY AND
EVOLUTION
Causes of Species Extinction
By:
Janet Brigida A. Catipon

2. Important Terms
• Biodiversity or Biological Diversity
sum of all the different species of animals, plants,
fungi, and microbial organisms living on Earth, and
the variety of habitats in which they live.
• Extinction
the end of existence of a group of organism,
caused by their inability to adapt to changing
environmental conditions.

3. • Species
Basic concepts in the classification of organism.
In simple term, a single species is a distinct kind of
organism with a characteristic, shape, size, behavior,
and habitat that remains constant from year to year.
• An ecosystem
 is a community of living organisms in conjunction
with the nonliving components of their environment,
interacting as a system. These biotic and abiotic
components are regarded as linked together through
nutrient cycles and energy flows.

4. Causes of Species Extinction
• Deforestation
• Taking Animals for Profit
• Hunting and Trapping
• Overharvesting
• Destruction of Habitat
• Pollution

5. Population
• is a group of living things within a certain area that are all of the same
species
Several Different Populations may be found in the community:
example: A Jungle Community - has a greater amount of biological
diversity than a cornfield.
Some Populations may be found in jungle community
can be very large
in number
Have fewer
members
Why do you think population sizes vary among organisms?
1. Population of Ants
2. Population of
Fungi
3. Population of
Ferns
1. Population of Tigers
2. Population of
Snakes

6. Communities
• Communities with many different species (a high
index of diversity) will be able to withstand
environmental changes better than communities
with only few species (a low index of diversity)
Vacant lots would have low I.D, since there are fewer species
distribution.
Grass lawn also would have low I.D,
Tree would also have low I.D.
Communities with many different species have a high I.D
Index of Diversity = Number of species x number of runs
Number of Trees

7. Measuring Population Density
• Population Density - is a measurement of population per unit area or
unit volume; It is frequently applied to living organisms, and
particularly to humans.
• Population can be of the same size, but they may have different
densities.
Differences in population density may be attributed to many factors:
1. When new members move in or out in an ecosystem
2. The Birth Rate and Death Rate
Population Density = number of individuals
Size of Area

8. LIMITING FACTORS
• Anything that limits the size of a population like certain
environmental conditions.
Limiting Factors keep population from:
 Increasing in size and
Help balance an ecosystem
Examples of Limiting Factors:
1. Availability of food 4. Light Temperature
2. Water and 5. Soil Nutrients
3. Living conditions

9. Carrying Capacity
The maximum population size an
environment can support is called
CARRYING CAPACITY
 If the population size rises above the
carrying capacity, organism die because
they cannot meet all their needs.

10. Endangered but not Extinct
• When species, population becomes so low that only few remain, the
species is considered ENDANGERED will possibly extinct.
• In the Philippines, some Terrestrial species like:
1. Tamaraw in Mondoro

11. 2. Mouse Deer in Palawan

12. 3. Philippine Deer

13. 4. Monkey-eating eagle, and some

15. Aquatic species like;
1. Dugong(manatee) found in Negros, Batangas, and Leyte are in danger
of EXTINCTION

16. Dugong(Mantee)

17. Threatened
• There`s a particular species that declines so fast that it becomes
endangered and it is said to be threatened.
• Ex. A study conducted by field biologists on population size and
distribution of Philippine fauna, they reported that as of 1991,
89 species of birds
44 species of mammals &
8 species of reptiles
These include also the Philippine Eagle or Monkey-eating Eagle
Are internationally
threatened

19. EXTINCTION
• Is the disappearance of a species when the
last of its members die.
Cause: Changes to habitats, due to
increasing population
Natural vegetation in the area has been
cleared.
Concrete structures and other organisms
gradually take over the area.
Some areas were destroyed by natural
disasters or by human activities.

20. Local and Global Issues that contributedto Species
Extinction
•Deforestation
- one of the country`s environmental problems is the rapid rate
at which trees are cut down.
- in the Philippines, the major causes of deforestation are:
@ Kaingin Farming
@ Illegal Logging
@ Conversion of agricultural lands to housing
projects
@ Forest Fires
@ Typhoons

21. • Kaingin Farming

22. As a consequence of cutting down trees, the
following effects are:
• Soil erosion
• Floods
• Decrease in wildlife resources that will
eventually lead to extinction
• Wildlife Depletion, deforestation is one of
the major causes of the disappearance of
wildlife species.

23. Dugong (manatee)
Philippine Eagle
Tarsier

24. Local andGlobal Issues that contributedto Species
Extinction
Water Pollution
A major problem in lakes, rivers and ponds is
EUTROPHICATION – is the process by which a body of
water becomes enriched in dissolved nutrients (such as
phosphates) that stimulate the growth of aquatic plant,
life usually resulting in the depletion of dissolved oxygen.
- it happens when the concentration of
organic nutrients that comes from domestic garbage and
thrown in bodies of water, increases rapidly.

25. Local andGlobal Issues that contributedto Species Extinction
• Effect on Water Pollution:
@ mass death of fish (fish kill)
- usually happens when there`s an increase in concentration of
organic nutrients in bodies of water – this condition causes algal bloom
and growth of aquatic plants. When the algae die, they sink to the
bottom and the process of decomposition proceeds. This process uses
up oxygen and as a result, aquatic animals die due to lack of oxygen.
PCB (polychlorinated biphenyl)
- one class of dangerous chemicals present in
water,
- toxic waste produced in the making of paints, inks
and electrical insulators
- fish are unable to excrete PCB on their bodies

26. EUTROPHICATION

27. Local andGlobal Issues that contributedto Species Extinction
• PCB(polychlorinated biphenyl)
-through the process of biological magnification, the PCB becomes
concentrated in the body tissues of water organism.
Biological Magnification is the build up of pollutants
in organism at higher trophic levels in the food chain
• Other Pollutants found in water are heavy metals:
lead, mercury, and cadmium – these metals are come from
factories that dump their wastes into rivers or lakes.

28. Local andGlobal Issues that contributedto Species
Extinction
• Air Pollution
cars are the one of the major contributors to air
pollution.
Pollutants can enter the air as gases, liquids or solids.
Cars burn fuel and produce harmful gases:
@ carbon dioxide
@ nitrogen oxides &
@ hydrocarbons

29. Harmful Pollutants found in Air
In Metro Manila where a
great volume of cars travel
each day, smog blankets
the area, nitrogen oxides
and hydrocarbons from car
exhaust react with water
vapour or dust particles
and produce new irritating
chemicals

30. Greenhouse Effect & Global Warming
• Greenhouse Effect – is the natural process of warming the
Earth.
- is a process of trapping of heat by gases in the
Earth`s atmosphere. Carbon dioxide acts like a blanket over the
Earth, holding in the heat that would otherwise radiate back into
space.
- but as carbon dioxide in the atmosphere increases,
greenhouse effect also intensifies this will lead to global warming.
• Global Warming - is an increase in the earth`s temperature
from the rapid buildup of CO2 and other gases. This in turn, could
change the world climate patterns – CLIMATE CHANGE

31. Local andGlobal Issues that contributedto Species Extinction
• Destruction of Coastal Resources
Coral reefs and Coastal mangrove forest in the Philippines serve as
breeding grounds and nurseries of marine fishes.
But due to man`s activities, coastal areas are getting destroyed
these activities include:
@ deforestation, agricultural activities, and mining activities
@ dynamite fishing and muro-ami
@ coastal areas` conversion to beach resorts, and
residential houses
@ overharvesting

32. Destruction of Coral Reefs Dynamite Fishing
Damaged mangrove areas

33. Local and Global Issues that contributedto Species Extinction
• Acid Precipitation - commonly known as acid rain.
Rainwater is normally acidic, because carbon dioxide is
normally present. Other pollutants, mostly sulfur and
nitrogen oxides, make rainwater even more acidic, with pH
of 5.6 or lower
• Acid Rain, can be harmful to living things.
@ It causes yellowing of leaves of trees and cause
leaves to fall.
@ Nutrients can be lost from the soil.

34. Acid Rain

35. Human Activities andOverpopulation
have cost the most of the environmental problems nowadays.
People are beginning to realize that the way they interact with the
environment must change to ensure the survival of all living
things. This is one of the big challenge to maintain resources
needed for survival while ensuring that they will still be available in
the future. This is a practice called SUSTAINABLE DEVELOPMENT –
Means that the rate at which society uses renewable resources
does not exceed the rate at which the resources are generated.

36. THANK YOU!!!!