Class Notes (834,241)
United States (323,678)
Biology (126)
BIOL 190 (47)
Angela Cox (29)
Lecture 22

BIOL 190 Lecture 22: Ecology 2
Premium

4 Pages
91 Views
Unlock Document

Department
Biology
Course
BIOL 190
Professor
Angela Cox
Semester
Spring

Description
If we study interactions between lobsters and other local species in Maine, what level of ecology are we studying? ● Communities Why might some of these penguins die? ● An important idea in our study of evolution is that the environmental impacts which individuals will survive and reproduce… and the environment constantly changes Evidence for Environmental Change ● Long term (slow change, millions of years) ○ Plate tectonics ● Short term (faster) ○ Succession Plate Tectonics ● Plate tectonics explains: ○ Why mesozoic reptiles in Ghana (West Africa) and Brazil look so similar ○ How marsupials were free to evolve in isolation in Australia Primary succession - starts with bare rock ******************* Secondary succession - response to a disturbance Human impact on the environment…. Geological time frame: climate cycles Global Climate Change Rising Temperatures ● 1991-2012 average temperatures compared with 1901-1960 average Bottom line- there is tremendous variation in the environment, and the environment changes over time Population Ecology How and why do populations change? ● Important to our study of evolution because populations evolve Population Ecology ● Population- a group of animals of the same species that live in the same general area ○ Populations must be defined ■ All the trout in one river, one part of a river, all rivers in the US ● Population ecology- study of factors affecting population ○ Size- number of individuals ○ Density- number of individuals per unit of area ○ Structure- how many individuals in each age group ○ Growth rate- how fast the population is growing Population density= size, the number of individuals Population growth rate ● How fast the size of a population increases ● Influenced by ○ Exponential growth rate of a species ○ Population limiting factors ○ Carrying capacity Exponential growth ● Maximum rate of annual growth (rmax) ○ Assumes no limits! ○ Characteristic for each species ○ Determined by: ■ Age at sexual maturity ■ # reproductive cycles per year ■ # offspring per cycle ■ % offspring that survive and reproduce Logistic growth ● Accounts for population limiting factor(s) Population Limiting factors ● Environmental factors that may affect reproductive success ○ Biotic ■ Infectious diseases ■ Predators ■ Pathogens ■ Competition ■ Parasites ● Abiotic ○ Flood, fi
More Less

Related notes for BIOL 190

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit