Populations chapter 5 in text

3 factors affecting population size

• Births• Deaths• Immigration and Emigration

Growth without limiting factors

Growth without limiting factors

• Under ideal conditions a population will show exponential growth – What are ideal conditions?

Limiting factors can be density-dependent or density-independent

• Density-dependent factors are limiting factors that depend on population size– Examples of density-dependent factors:

– Examples of density-independent factors:

Density-dependentor

Density-independent?

Density-dependentor

Density-independent?

Density-dependentor

Density-independent?

Growth with limiting factors• Under such circumstances a population show

an s-shaped curve, indicating logistic growth

What is “K”?

What is “K”?• “K” stands for a concept called carrying capacity,

which is the largest number of individuals with in a species that the environment can support.

What is shape of global human growth?

What is shape of global human growth?

What is shape of global human growth?

http://www.google.com/url?sa=i&rct=j&q=human+population+graph&source=images&cd=&cad=rja&docid=PcdPXAsee9YDUM&tbnid=iuJySsZ85kzZmM:&ved=0CAUQjRw&url=http://www.truthmove.org/content/population/&ei=PiuSUbL-HZPI0AGouICwCg&bvm=bv.46471029,d.dmQ&psig=AFQjCNHAs6E-hPxyDemcVoRLF1WwJzrMoQ&ust=1368620215927353

r-selected vs. K-selected species

Characteristics of r- and K-selected organismsr-organisms K-organisms

short-lived long-lived

small large

weak strong or well-protected

waste a lot of enrgey energy efficient

less intelligent more intelligent

have large litters have small litters

reproduce at an early age reproduce at a late age

fast maturation slow maturation

little care for offspring much care for offspring

strong sex drive weak sex drive

small size at birth large size at birth

What are your demographics?• Demographics: the statistical data of a population,

especially those showing average age, income, education, etc.

Age-structure diagrams predict future population size, looking at age, gender

• Match the countries: US, Germany, Kenya, Italy

Age-structure diagrams predict future population size

• Match the countries: US, Germany, Kenya, Italy