Species that play roles affecting many other organisms in an ecosystem
(Compare: Foundation Species, Indicator Species, Native Species, Non Native)
Why are sharks important?
Because some of them are Keystone Species which means that we and other species need
keep control on certain fish population
What threats do sharks face?
Many Sharks are caught for their valuable fins and then thrown back alive into the water (fins
-they grow slowly
-have only a few offspring per generation.
Name 3 reasons why insects are important to
-Many of the earth’s plants species depends on insects to pollinate their flowers
-Insects that eat other insects such as Praying Mantis to help control
the populations of at least half the species of insects we call pests
-Some insects also play a key role in loosening and renewing the soil that supports plant life on land
Why are alligators so important?
-Because of its important ecological role in helping to maintain the sustainability of
the ecosystems in which it is found
- Alligator eat large gar, a predatory fish, which helps maintain the population of game fish such as bass and bream that like to eat gar.
-As alligators create gator hole and nesting mounds, they help to keep shore and open water areas free of invading vegetation
The Theory of Evolution
explains the idea that all species descended from earlier, ancestral species in other words, Life Comes From Life
3 reasons why the fossil record is uneven
-Some forms of life left no fossils
-Some fossils have decomposed
-The fossils found so far represent probably only 1% of all species that have ever lived.
How natural selection works
Is Genes mutate, Individuals are selected, and populations evolve such that they are better adapted to survive and reproduce under existing environmental conditions.
3 conditions are necessary for evolution to occur by natural selection?
-Allow our skin to become more resistant to the harmful effects of UV radiation
-Our lungs to cope with air pollutants
-Our livers to better detoxify pollutants
3 common misconceptions about evolution?
-Humans descended from
-Survival of the fittest means survival of the
strongest (Fitness is a measure of reproductive success not strength)
-organisms develop certain traits because they need them.(ancestors have)
Define speciation and describe the two phases of speciation.
Speciation is formation of two species from one species because of divergent natural selection in response to changes in environmental conditions; Usually takes thousands of years.
What is the difference between background and mass extinction?
-Background extinction rate normal extinction of various species as a result of changes in
local environmental conditions.
-In Contrast, Mass Extinction is a significant rise in extinction rates above the background
How many mass extinctions have we had in the past?
5 mass extensions
Are we currently in a mass extinction?
Yes because of human activities
What occurs after a mass extinction and how long does it take to rebuild biological diversity?
-An increase in species diversity over several million years as new species have arisen to
occupy new habitants or to exploit newly available resources
-What occurs is the evolution of new species that can fill unoccupied ecological roles or newly
What is the difference between an ecological
niche and a habitat?
Ecological Niche it is a species’ way of life in a community and includes everything that affects its survival and reproduction, such how much water and sunlight it needs and etc.
-Habitat is where specie lives while Niche is the pattern of living
What is a generalist species?
Generalist Species have Broad Niches, which mean they can live in many different places,
eat variety of foods, and often tolerate a wide range of environmental conditions
-ex; are flies, cockroaches’ mice rats’ raccoons and humans
What is a specialist species?
-Narrow Niches they may be able to live in only one type of habitat, use just one or only few types of food, or tolerate narrow range of climatic and other environmental conditions,
-Ex; Shorebirds, Chinas Giant Panda
Cockroaches rule! What makes them so successful?
They are Generalist, they can eat almost anything and live anywhere except in polar regions, some can go a month without food and can withstand a massive doses of radiation, can survive being frozen for 48 hours lastly they have a high reproductive rate
Why should we care about the loss of global (or local) biodiversity?
-Because they play a major role in our ecosystems and can preform more than one task to the ecosystem
Why should we care?
-Because adult frog play an important ecological role in our biological communities such as eat insects and also we have been using them for medical treatment and they are sensitive to environment change are indicators of dramatic changed in our environment