Chapter 2 - Ecological Evolution Flashcards
What is the first law of ecology?
Everything is connected to everything else
What does ecology study? (large to small)
- biosphere (planet as whole)
- ecosystems (biotic and abiotic)
- community (diff species interacting in an area)
- population (group of organisms of same species)
- organism (singular)
Who was Charles Darwin and Alfred Russell Wallace?
Ecologists that provided scientific foundations for today’s ecologists
- Darwin travelled the world recording specimens & developed view that diversity of nature was result of evolution in which natural selection favoured some variants within species through a struggle for existence
- Wallace had same theories as Darwin
Define 4 traits of evolution by natural selection
- Individuals form a population and are not identical
- Some variation is heritable
- Most individuals die before reproducing and those that do reproduce will not do so at maximal rate
- Different ancestors leave different numbers of descendants, so those that contribute most have greater influence on heritable characteristics
What is evolution?
It is the change, over time, in heritable characteristics of a population or species that is inevitable
What does fitness refer to in terms of evolution?
It is a species’ ability to survive, grow and reproduce in a particular environment (and only that environment).
What is natural selection?
It is the selection of the species with the genetic variations that allow it to survive and reproduce in the environmental conditions it exists in. Natural selection has no future aim.
What is a common garden?
As the characteristics of species may vary over a geographical range (ex. sapphire rockcress grows at high and low elevations but the one at low is threatened by urbanism), both types are grown in a common garden to eliminate the influence from the contrasting environments. Helps to determine specific characteristics, like which is more drought tolerant.
What is hybridization?
It is the production of offspring sharing characteristics of two different parents. It requires the exchange of genetic material between two plants, meaning both must be flowering at the same time.
What is a reciprocal transplant experiment?
It tests whether organisms have evolved to become specialized to life in local environments by comparing performance when grown at home and away from home. (plants both types in both locations)
What is industrial melanism?
It was introduced when natural selection by pollution became a factor. It is the phenomenon in which black(ish) forms of species (like moths) now dominate industrial areas. (blend in better)
What does coevolve mean?
It is when two species are in a never-ending cycle of natural selection - things evolve in response to one another
Ex. parasites that are more efficient at infecting hosts will survive; however, natural selection also favours more resistant humans
What is speciation?
It is the formation of new and distinct species through evolution
What is ecological speciation?
It is speciation where there’s an ecological source of divergent selection and is a means of reproductive isolation
What is pre-zygotic isolation?
It is mechanisms that prevent species from breeding in the first place (ex. geographically)
