1. Human Population Math

2. Population Density # of indiv. of a species unit of area A better way to describe the size of a population ex. 270,000,000 people = 29 people/Km 2 in the US 9,166,605 Km 2

3. Birth and Death Rate b = birth _ or Births per thousand Total population1000 d = death or Deaths per thousand Total population1000 ex. b = 23, 452/942,721 = 0.025 x 100= 2.5% Same as 25/1000 = 0.025 x 100= 2.5%

4. What Causes Populations to Change in Size? Rate of change ( r ) = Four ways to find r: When using r, identify your variables and then pick the equation that fits!

5. Rate of change ( r ) = 1. Total births - total deaths/ total population r = 23,452 -17, 228 = 0.0066 x 100=.66% r = 23,452 -17, 228 = 0.0066 x 100=.66% 942,721 942,721 2. birth rate (b) -death rate (d) r = 25 - 18 = 0.007 x 100=0.7% r = 25 - 18 = 0.007 x 100=0.7% 1000 1000 1000 1000

6. Rate of change ( r ) = 3. 3. (Total births + total immigration) - (total deaths + total emigration) / total population r = (23,452 + 9842)-(17, 228 + 2450) = 942,721 = 0.014 x 100 = 1.4% 4. (birth rate (b) + immigration rate(i)) - (death rate (d) + emigration rate (e) ) x 100 r = (25 + 10) - (18 + 3) = 0.014 x 100 = 1.4% 1000 1000

7. Doubling Time

8. Time to take for a population with a stable growth rate to double in size Doubling Time ( t d ) = t d = 70% or.7 r r Ex. Brazil will double its population in how many years with the present growth rate of 1.7%? A:.7/0.017 or 70%/1.7% = 41.2 years

9. Maximum Population Growth (MPG) Influenced by Biotic Potential – – different for each species – – can change with conditions MPG is always exponential under ideal conditions

10. You figure out the growth Rate of a Pop: Remember: r = (b - d ) + (i - e ) b =.01 d =.005 i =.001e =.01 So now: Calculate growth rate and Calculate doubling time

11. Determining future Pops: Remember: N (t) = N 0 e rt N(t) = population after t years N 0 = initial population size r = growth rate t = time

12. You Determine the future Pop of Duttania: Remember: N (t) = N 0 e rt The island of Duttania has 435 people. Their growth rate is 2%. What will be the population after 10 years? A: 531 people.