Ecology I.

Introduction to ecology

Ecology• The science of the study of the

relationships between living things and their environment

• The environment could be:– Biotic = other species

– Nonbiological (abiotic) = physical, chemical, geographical, geological factors

Ecological sciences

• General ecology• Plant ecology, animal ecology, microbial

ecology• Environmental science• Environmental protection and

management• Hydrobiology (water ecosystems)• Limnology (freshwater ecosystems)• Environmental geology and geography

Applications of ecology in medicine• Medical ecology• Preventive medicine (hygiene)• Social medicine• Epidemiology• Toxicology• Genotoxicology – deals with mutagenic effects

of environmental factors• Medical parasitology• Medical microbiology• Alergology• Geographic medicine• Medical geology

Genetic and environmental background of diseases

INHERITANCE ENVIRONMENT

(genetic factors) (environmental factors)

Diabetes mellitus

Tumor diseases

Phenylketonuria

Injuries

Infections

Cystic fibrosis

Intoxications

Color blindness

Deafness

Basic ecological terms

Population

• A group of individuals of the same species living in the same area or interbreeding and sharing genetic information.

Population of species A

Population of species B

Ecosystem

• Ecological community + nonbiological factors

• The minimum system that includes and sustains life

• It must include:– An autotroph– A decomposer– A source of energy– All the chemical elements required by the

autotroph and the decomposer

Abiotic factors

Ecosystem

Population of species A

Population of species B

Population of species C

Community

Food web (trophic „chain“)

Producers (green plants, algae, autotrophic bacteria)

Primary consumers (herbivores)

Secodary consumers (carnivores)

Decomposers (heterotrophic bacteria, fungi)

Decay of organic matterRelease of inorganic nutrients

Solar energy

Energy flow within food web

Biomass of producers

Biomass of primary consumers

Loss of

energy

Loss of

energy

Biomass of secondary consumers

Interspecific relationsRelation Species A Species B

Neutralism 0 0 No relation, neither effects the other

Commensalism + 0

Protocooperation + + Free relation

Mutualism („symbiosis“)

+ + Closed relation

Allelopathy (inhibition)

0 (+?) – Species A produces compounds harmful for species B

Parasitism + –

Predation + –

Competition + –

Commensalism:One species benefits, the other doesn't but

is not harmed.

Interspecific relationsRelation Species A Species B

Neutralism 0 0 No relation, neither effects the other

Commensalism + 0

Protocooperation + + Free relation

Mutualism („symbiosis“)

+ + Closed relation

Allelopathy (inhibition)

0 (+?) – Species A produces compounds harmful for species B

Parasitism + –

Predation + –

Competition + –

Protocooperation

A hermit crab and the sea anemone

Interspecific relationsRelation Species A Species B

Neutralism 0 0 No relation, neither effects the other

Commensalism + 0

Protocooperation + + Free relation

Mutualism („symbiosis“)

+ + Closed relation

Allelopathy (inhibition)

0 (+?) – Species A produces compounds harmful for species B

Parasitism + –

Predation + –

Competition + –

Mutualism• Giant Clam

Tridacna squamosa

• The mantle (soft tissue) within the shell is brightly coloured brown, blue and/or green. This is due to the microscopic algae known as zooxanthellae living inside the tissues which photosynthesise (manufacture food) from sunlight and the waste metabolic products of the clam. They are then "harvested" by the clam as supplementary food.

• Despite being "farmed" this way, the algae are assured of a safe "residence" and a continued supply of nutrients.

Another example of mutualism- lichens

Interspecific relationsRelation Species A Species B

Neutralism 0 0 No relation, neither effects the other

Commensalism + 0

Protocooperation + + Free relation

Mutualism („symbiosis“)

+ + Closed relation

Allelopathy (inhibition)

0 (+?) – Species A produces compounds harmful for species B.

„antibiosis“

Parasitism + –

Predation + –

Competition + –

Antibiosis

Epicoccum nigrum and Sclerotinia sclerotiorum

Antibiosis test of bacteria

Interspecific relationsRelation Species A Species B

Neutralism 0 0 No relation, neither effects the other

Commensalism + 0

Protocooperation + + Free relation

Mutualism („symbiosis“)

+ + Closed relation

Allelopathy (inhibition)

0 (+?) – Species A produces compounds harmful for species B.

„antibiosis“

Parasitism + –

Predation + –

Competition + –

Parasites in humans• Viruses• Bacteria• Fungi (e.g. some parasitic yeasts)• Protozoa or Protista (e.g. Trypanosoma,

Plasmodium, Toxoplasma)• Flatworms (e.g. liver fluke)• Roundworms (e.g. ascarid)• Insects (e.g. mosquito)• Arachnoids (e.g. tick)

Microbiology and parasitology• Viruses

• Bacteria

• Fungi

• Protozoa

• Flatworms

• Roundworms

• Insects

• Arachnoids

Medical microbiology

Medical parasitolgy

Plasmodium – a typical parasite transmitted by mosquito

See you next week!

• Practicals – a short test in basic ecology is not excluded!