Parasites

Why don’t parasites kill their host

because most can’t eat the host after it dies, and they need a live host to spread to others

what’s an example of parasitic mind control in insects

cordyceps fungus infecting ants, making them climb high to spread the parasites spores

What’s special about the cordyceps evolution

different species of cordyceps have evolved for specific insects

How do parasites help biodiversity

they keep dominant species in check, maintaining balance

What are examples of mind control organisms

protozoans, fungi, and some invertebrates

What is commensalism

one species benefits, the other is unaffected

what is mutualism

both species benefit from each other

what is competition

use/defense of a resource that reduced its availability to others

what’s more intense: infraspecific or interspecific competition

intraspecific because members need the same resources

What does infraspecific competition mean

When competition happens between individuals of the same species for limited resources

What does interspecific competition mean

The struggle between different species for the same limited resources

What is a limiting resource

a scarce resource that limits population growth

What does the competitive exclusion principle state

Two species can’t coexist if they rely on the same limiting resource

What did the flour beetle experiment show

species that use resources best in certain environments outcompete others

What happened in the barnacle experiment

removing one species allowed the other to expand its range

what’s resource partitioning

dividing resources to reduce competition

what is character displacement

evolutionary changes to avoid direct competition

what reveals community connections

unexpected effects when communities are disrupted

what’s a trophic cascade

Where changes at one level of a food chain have indirect efects that ripple down through other levels, impacting the whole ecosystem

What are trophic levels

levels in the food chain, for example: producers > consumers > top predators

How much energy moves from one trophic level to the next?

only 10-15%

Why are there fewer top predators

They require more space and energy, which limits their numbers

What happened when wolves were reintroduced to yellowstone

elk population declined, vegetation recovered, rivers stabilized

What is an example of “landscape of fear”

Elk avoiding areas with wolves, allowing vegetation to regrow

What other animals returned because of the reintroduction of wolves in the yellowstone

birds, beavers, bears, mice, rabbits, hawks

what happened to coyotes after wolves returned

their population declined, helping pronghorns and small mammal populations to increase

What is a keystone species

a species that has a large impact on its ecosystem