introduction to ecology part ii. autotrophs vs heterotrophs what is a producer – autotrophs like...
TRANSCRIPT
Introduction to Introduction to Ecology Part IIEcology Part II
Autotrophs vs HeterotrophsAutotrophs vs Heterotrophs
What is a producer– Autotrophs like plants, protists, and bacteria
that make their own food
What is a consumer:– Heterotrophs that cannot make their own
food
Species InteractionsSpecies Interactions
Predation– An individual of one species eats all or part
of an individual of another species
– Predator – organism eating
– Prey – organism being eaten
Species InteractionsSpecies Interactions
Predator Adaptations:– Neutral selection favors the evolution of
predator adaptations for finding, capturing, and consuming prey
Acute heat sensor to webs to camouflage hair to specialized teeth
Ex 1: Rattlesnake have acute sense of smell and heat sensitive pits below their nostrils
Ex 2: Sticky webs of spiders to flesh cutting teeth of wolves
Species InteractionsSpecies Interactions
Predator Adaptations cont.– Natural selection also favor prey to be able to
avoid, escape, or ward off predators– Animal prey adaptations:
Hide, camouflage, chemical defense, fake eyes and heads, bright colors, to mimic other dangerous animals
– Plant prey adaptations: Defense includes: sharp, thorns, spines, sticky
hairs, tough leaves, to being poisonous, irritating, or bad tasting.
CompetitionCompetition
Interspecific competition:– Is a type of interaction in which two or more
species use the same limited resources
– Two populations competing for the same resource may end up reducing/eliminating one of the competitors
Competition cont.Competition cont.
Competitive exclusion:– Is where one species uses the limited
resources more efficiently than the other species does
– Ex: Barnacles off the coast of Scottish coast between Chthamalus stellatus and Semibalanus balanoides
The C. stellatus could live high and low on ‘shore rock” but due to competition S. Balanoides out competed it restricted the C. stellas to the upper portion of the shore rock
SymbiosisSymbiosis
Symbiosis is a close, long-term relationship between two organisms
There are three types of symbiotic relationships:– Parasitism– Mutualism– Commensalism
SymbiosisSymbiosis
Parasitism:– In parasitism, the prey is called the host– Predator is called a parasite– One organism is harmed (host) while the
other organisms benefit (parasite)– Usually does not result in host death
Examples: Aphids, lice, leeches, fleas, ticks, and mosquitoes
SymbiosisSymbiosis
Parasitism cont.– Ectoparasites:
Live inside their hosts body Ex: Protists; tape, heart, round worms
– Parasites have a negative impact on their host’s health
– Host defense: Skin, tears, saliva, mucus membranes and the
immune system
SymbiosisSymbiosis
Mutualism:– Relationship where both (two) species have
some benefit from each other– Pollination is the most important mutulistic
relationship on Earth– Termites are able to digest cellulose due to a
mutulistic protozoa called Trichonympha
SymbiosisSymbiosis
Commensalism:– Is an interaction in which one species
benefits and the other is not affected
– Species that scavenges for leftover food items are often commensal species
Best known examples are small tropical fishes in relation to sea anemones
Species Richness:Species Richness:
Is the number of species or simple count of species in the community
Each species contributes one count to the total regardless of whether the species’ population is one in 1 million
Species RichnessSpecies Richness
Varies with latitude – the closer a community is to the equator the greater the number of species– Species is the greatest in the tropical rain forest
Larger areas usually contains more species than smaller ones
Species interaction also promotes species richness. (Competition can keep species from overcrowding other)
SuccessionSuccession
Ecological succession is a gradual sequential growth of a community of species in an area
SuccessionSuccession
Primary Succession:– Development of a community in an area that
has not supported life in the past
– Bare rocks, sand dunes, or volcanic island
– No soil present (can take 200+ years to reach vegetation)
SuccessionSuccession
Secondary Succession:– Sequential replacement of species that
follows disruption of an existing community– Regrowth of organisms after a severe natural
disaster (fire, tornado) or farming, logging, or mining
– Soil already present (takes about 100 years)
SuccessionSuccession
Pioneer Community:– A community that is actively undergoing
succession
– Not stable, still changing with time
SuccessionSuccession
Climax Community:– A community that reaches a stable end point
(redwood forest)