“living together”
one organism benefits by feeding on another
prey = host host is harmed or weakened differentiate between predators and
parasites…parasites are usually smaller and more
numerous than hostparasites usually have complex life cycles
coevolution…examples include malaria and sleeping sickness
LIVER FLUKE
both organisms benefit examples…
lichensbacteria living in the digestive tracts of
cows and termitesants and acaciamycorhizae and legumes
lichens
WHITEBARK PINE AND CLARK’S NUTCRACKER
one species benefits and the other is relatively unharmed
controversial – why???examples – barnacles on a whale
GREAT WHITE SHARK AND REMORA
predators kill and eat other organisms some scientists include herbivores
(plant-eaters) in this category predators are usually larger and less
abundant than their prey
yes, it’s a predator!
these interactions result in coevolution evolution of camouflage, skilled hunting
ability, poisons some examples
counteracting behaviors –bats and moths
some examples (continued)camouflage – colors,
patterns and shapes that resemble surroundings, these organisms do not flee – cheetahs, frogfish
warning coloration – usually bright, these organisms taste bad or are poisonous
some examples (continued)mimicry – one species has evolved
resemble another Müllerian mimicry – occurs among different
distasteful species such as monarch butterfly (poisonous) and viceroy butterfly (distasteful)
some examples (continued)mimicry
Müllerian mimicry – results in faster learning by predators such as the black and yellow color pattern that is repeated in nature
some examples (continued)mimicry
Batesian mimicry – harmless animals resemble poisonous ones
some examples (continued)mimicry
startle coloration – patterns of color that resemble much larger/dangerous organisms
some examples (continued)mimicry
aggressive mimicry – predators entice prey to come close by resembling something attractive to them
the real deal…only about 10 cm long
some examples (continued)chemical warfare – both predators and prey
use toxic chemicals plant poisons venomous snakes and spiders ink emitted by certain mollusks
some examples (continued)plants and herbivores have also coevolved
milkweed is toxic to all organisms except the monarch butterfly…these butterflies store these chemicals and use them as their chemical defense weapon
change in teeth of grazing animals to be able to eat grasses that have evolved to have a hard outer covering (made of silicone)
competition – occurs when a resource is limited
intraspecific vs. interspecific competition
classic studies of competitionParamecium caudatum and
Paramecium aurelia – showed that 2 species with similar requirements cannot coexist (for an extended time period)
classic studies of competition (continued)warbler study – each
species occupies its own niche
niche – all aspects of an organism’s habitat, how it “makes a living” and its physical environment
no/minimal niche overlap = no competition
classic studies of competition (continued)barnacle study - by excluding each species
it was determined that they could both inhabit the low tide areas
fundamental niche - set of resources a population is theoretically capable of using under ideal conditions
realized niche - the resources a population actually uses
competitive exclusion principle (Gause’s Principle)Two species competing for limited
resources cannot coexist in the same place at the same time.
click this box!
organisms with high biotic potential that are introduced (accidentally or purposely) into non-native ecosystems where there is little environmental resistance biotic potential – maximum reproductive ability in an
optimal environment so what’s the big deal? they can effect…
natural resources human health economy
invasive species have no predators, diseases, parasites, other organisms competing for the same resources and limiting environmental factors
click on this carp guy
disrupt natural communities and ecological processes
cause harm to the native species in that ecosystem by competing with them for the same resources
invasive species can outcompete native species
ecosystems often become less biodiverse (more susceptible to further damage)
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