Running Larve 2 times, first time with birth rate = 2, second time with birth rate = 3.

Model Variables:
0. Initial Population: US census 2008 est./ 1000
1. life expectancy: 78 (US average 78.11)
2. birthrate: a) 2.0 and b) 3.0 / fertile female (maximum children per female)
3. fertility: if (sex == female AND fertility_minimum_age < age < fertility_maximum_age )
4. fertility_minimum_age = 25, fertility_maximum_age=30
5. begintime = 2009, endtime= begintime+n years (e.g. 250)

Thesis:
In the model's first test run, a few oddities in the behavior were shown. The most curious was the fact that the population died. This was not immediately worrisome, as there were a few build in factors leading to this behavior: 1. a large portion of the initial population has passed the fertility maximum age of the model, no longer being capable to reproduce by the model’s logic; 2. a significant portion of the initial population has passed the life expectancy age, at which the model kills a specimen; 3. the maximum number of children per female assuming a sex ratio of 100 would make it impossible for the population to grow.

Population Size


Comment: With a birth rate of 3 the population initially grows but reaches an Evolutionary Stable Strategy (ESS) after 75 years, while the population with a birth rate of 2 starts to die off after 30 years reaching close to extinction around 200 years.

Sex Ratio

Median Age


Comment: the peaks and lows in the Median Age are cause by the model’s logic, of forcing each woman at 25 years to give birth to 1 child each year for 3 years.