Class Notes (834,339)
United States (323,712)
BIOSC 0160 (72)
Nilson (19)
Lecture 22

BIOSC 0160 Lecture 22: Biology 2 Lecture 3.5: Population Ecology 2

2 Pages
Unlock Document

Biological Sciences
BIOSC 0160

Biology Week 14 4617 Lecture 3.5 How can we model population growth? How does a species life history influence population growth? Do not need to readunderstandknow chapter 54.3 R0= net reproductive rate = average number of female offspring that a female produced over her lifetime o = sum 0 to k (older age class in population) of lxmx lx = NxN0 mx given o <1: shrinking o =1: stable (replacement rate) o >1: growing o Cannot be compared across species because it is scaled to generation time More information as to what is causing changes in the population growth rates Life history: describes how an individual allocates resources to growth, survival, and reproduction o Lower survivorship but higher fecundity vs. o Higher survivorship, but lower fecundity o Tradeoffs: how organisms allocate their limited resources (allocate to offspring less to survival and vice versa) Exponential growth: as population size increases, the number of new individuals added to the population per unit time accelerates o N t+1 N t birth death (ignore immigration and emigration) o N t+1 N t bN t dN tb=birthsindividuals in sample, d=deathsindividuals in the sample) o Nt = N tbd) o bd = r; Nt = rt o r<0: population is shrinking o r=0: population is stable (corresponds with0R = 1) o r>0: population is growing r corrects for generation time and can use it to make comparisons across species o r=0.1: the population grows by 10 each time period If t = 10, then the population adds 1 in one year If N = 100, then the population adds 10 in one year t o r does not change with size of population, exponential population growth is considered density independent o We observe exponential growth when A few individuals found a new population (founder effect) A population experiences a catastrophic event and then begins to recover from a few individuals (bottleneck effect) o Eventually exponential growth slows
More Less

Related notes for BIOSC 0160

Log In


Join OneClass

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

Sign up

Join to view


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.