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!