Chapter 20 Flashcards
What are the 5 main threats to Biodiversity (HIPPO)
H - Habitat Destruction
I - Invasive Species
P - Population (of humans)
P - Pollution
O - Overexploitation/Over harvesting
Habitat Destruction example
Costa Rican Rainforest
Invasive Species example
1960s Nile Perch into Lake Victoria in East African as food wiped out > 200 small native species
Population (of humans) example
1975-2075 greatest population growth, South Asia, Africa, and Latin America
Pollution example
Plastic pollution in the sea, burning of fossil fuels
Overexploitation/Over harvesting example
whaling - Atlantic Grey whale extinction
-> includes “exotic” pets
Define and describe biodiversity “hot spots”, where they occur.
Biodiversity “hot spots” -> small areas with huge number of endangered species
Occurs where -> Tropics, Islands, and Mediterranean (total < 1.5% of earth land surface)
Define endemic species
Only occurs in one place
parasitism
-positive effect on the symbiont and negative effect on the host
-Ex: giant tapeworm in whale; tapeworm gets good and shelter (in whale intestines); whale gets weaker (depriving the whale of nutrients)
Interactions between Species (biotic factors)
-Competition
-Predation
-Symbiotic relationships
define and describe ecological niche
total of a species use of resources of its habitat
define and describe competitive exclusion principle
-No 2 species can occupy an identical niche → one species wins and eliminates the other
-Ex: 2 species of paramecium (protist) → “winner” uses resources more efficiently and prolly reaches sexual maturity faster → reproduces faster → local extinction in a beaker
Predator
consumer
Prey
food
who does natural selection favor
both predator and prey
Co-evolution
1 species evolved in response to another (over time, over many generations)
types of co-evolution
Predator-prey
Herbivore-plant
Pollinator-plant
Parasite-host
Prey defenses
-Cryptic coloration
-Warning coloration
-Mimicry (2 types)
Cryptic coloration
camouflage; ex: stick insects
Warning coloration
usually toxic with bright colors (flashing a big warning saying im toxic); ex: poison arrow frog, blue-ringed octopus
Mimicry
copycat adaptation
1. Batesian
2.Mullerian
Batesian
harmless species mimics a harmful one
Ex: hawk moth larva (caterpillar) mimics a snake head
Mullerian
two harmful species look similar
Ex: bees and wasps
define symbiosis, list the 3 types
Symbiosis → two species living together indirect contact; Symbiont = smaller part, Host = larger part
commensalism, parasitism, mutualism
commensalism
-positive effect on the symbiont and a neutral effect on the host
-Ex: barnacle on a whale; barnacle finds a place to live and a free ride to filter feed
mutualism
-positive effect on the symbiont and host
-Ex: yucca and the yucca moth; yucca moth is the soul pollinator of the yucca; moth gets a mating spot (flowers) → female lays fertilized eggs in the ovary of the yucca flower; larvae that hatch eat the seeds in the fruit (not all but some)
Species diversity in communities
More diversity → percentage of all species are the same
Disturbance of communities
cause damage
Natural disturbances
Earthquakes, floods, fires
Intermediate disturbance hypothesis. why?
Medium amount of disturbance is best for species diversity. why?
-Too much → species can be wiped out; no time to adapt
-Too little → one species can dominate; out competes the others
effect of humans
Lead to the decrease in species diversity
Ex: humans use roughly 60% of earth’s land surface, mostly for crops (monocultures); and grazing (dairy and beef cattle)
primary ecological succession
recolonizing of bare rock; not even soil
Ex: volcanic eruptions, retreating glaciers
secondary ecological succession
recolonizing where there is still soil
Ex: fire, floods
