Biodiversity and evolution

BIODIVERSITY AND EVOLUTION

Causes of Species ExtinctionBy:

Janet Brigida A. Catipon

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

•SpeciesBasic 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.

Causes of Species Extinction• Deforestation

• Taking Animals for Profit

• Hunting and Trapping

• Overharvesting

• Destruction of Habitat

• Pollution

Population• is a group of living things within a certain area that are all of

the same speciesSeveral 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 largein number

Have fewer members

Why do you think population sizes vary among organisms?

1. Population of Ants2. Population of Fungi3. Population of Ferns

1. Population of Tigers2. Population of Snakes

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

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

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 Temperature2. Water and 5. Soil Nutrients3. Living conditions

Carrying CapacityThe 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.

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

2. Mouse Deer in Palawan

3. Philippine Deer

4. Monkey-eating eagle, and some

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

Dugong(Mantee)

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 birds44 species of mammals &8 species of reptiles

These include also the Philippine Eagle or Monkey-eating Eagle

Are internationally threatened

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.

Local and Global Issues that contributed to 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

• Kaingin Farming

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.

Dugong (manatee)

Philippine Eagle

Tarsier

Local and Global Issues that contributed to 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.

Local and Global Issues that contributed to 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

EUTROPHICATION

Local and Global Issues that contributed to 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.

Local and Global Issues that contributed to Species Extinction• Air Pollutioncars 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

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

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

Local and Global Issues that contributed to 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

Destruction of Coral Reefs Dynamite Fishing

Damaged mangrove areas

Local and Global Issues that contributed to 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.

Acid Rain

Human Activities and Overpopulation

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.

THANK YOU!!!!