Population growth

[Turjan]

Just to get the idea from some (old) Unesco data for the whole mankind:

Year - total population - annual growth rate - doubling time in years

8000 B.C. - 8 millions - 0.0007% - 100,000
1 - 300 millions - 0.046% - 1,500
1750 - 800 millions - 0.06% - 1,200
1900 - 1,650 millions - 0.48% - 150
1970 - 3,700 millions - 1.9% - 36

It's easy to see influences from technical and medical advancement, etc., on the growth rate.

 

[Mishihari Lord]

You made me curious so I put together a quick spreadsheet with the following assumption:

The initial population of 100 people are all 20 years olds.
All adults between 20 and 40 produce a child every 2 years (in pairs, of course)
There is a uniform probability of dying from age 0 to age 100, with an average lifespan of 70 years. Anyone whe reaches age 100 dies.

The final population in 200 years is 1,725,785

Admittedly this is a high upper bound for the population implying that they're living in some kind of paradise, but it does give some idea as to what is possible.

 

[Evilhalfling]

Okay using my formula and the 1% and 2% per anum growth rates .....


Poulation = (rate of births(over 1 yr) - rate of deaths(over 1 yr) +1 )POWER 200 * intial population.

the logic of this formula is that (rate of births(over 1 yr) - rate of deaths(over 1 yr) +rate of migration +1) = growth Rate = G
Pop (0) = intital populaion = 100

so Pop(yr1) = G*Pop(0)
Pop(2) = G*(G*Pop(0))
Pop(3) = G*(G*(G*Pop(0)))

growth rate 1% = (1.01 to the POWER 200) *100 = 731
growth rate 2% = (1.02 to the POWER 200) *100 = 5248

With as much land as you have carrying capacity should not be a problem for this level of population numbers.

 

[evildmguy]

I looked into this a while ago and created an excel spreadsheet to show me population growth, given birth rate, death rate, immigration, emigration, carrying capacity of the land, mass migration and deaths due to war. If you would like it to use as a base, send me an email to jonport (at) mchsi (dot) com and I will clean it up and send it to you. I can also send to you the documents I used to create this.

(I don't get email responses when someone replies to this thread, so you will have to send me the request to the above email.)

FWIW: My excel sheet showed a population of 668 after two hundred years, using 100 starting, 2% growth and 1% death with a 1.5 million land cap.

Have a good one! Take care!

edg

 

[Chacal]

All adults between 20 and 40 produce a child every 2 years (in pairs, of course)

Admittedly this is a high upper bound for the population implying that they're living in some kind of paradise, but it does give some idea as to what is possible.

Hmm, producing a child every 2 years for 20 years...

We 've got different definitions of paradise

Chacal

 

[Nathal]

Hmm, producing a child every 2 years for 20 years...

We 've got different definitions of paradise

Chacal

Damn, that's funny. I believe in 1800 the average woman had 7 children in her lifetime. Today that number is down to 4.3

...that .3 child must have a funny face.

 

[MerakSpielman]

Damn, that's funny. I believe in 1800 the average woman had 7 children in her lifetime. Today that number is down to 4.3

...that .3 child must have a funny face.

You also have to take into account infant mortality. How many of the 7 children survived past their first year?

In a D&D world, assuming you have some benevolent clerics who are willing to cure disease and whatnot for free on babies, the population growth could be staggeringly huge.

 

[Tonguez]

Can I just add a real life example that starting with my grandparents (bless their souls) born in 1910 (grandfather) and 1911 (grandmother) who had 19 children (17 reaching adulthood) I have 98 first cousins (a few now deceased).
I've lost count but the family is now at the 6th Generation and has around 400 members.

Now thats in less than 100 years with a starting population of 2 with an average lifespan which is unfortunately less than 60yrs for males, more for females.
So assuming the 400 current members have an average of 1 children every 25 years (as opposed to 5.7 for the original cohort) we could have 6400 people after 200 years and thats from a base population of 2

multiply by 100 we get 640000 adjust that to the carrying capacity of the land (ie guess a good number) and yep its all good


NB Just as an aside, studying Polynesian folklore (my specialty) you'll find usually a break of around 9 generations (or approx 200 yrs) between traditions of the founding population (which was often less than 100 and may have been no more than 20) and the next tradition cycle (usually internal migrations).

Most have assumed that it is at this point that the 'geographic carrying capacity' pressures set in forcing internal migrations and social rearrangements to occur...

 

[Mishihari Lord]

Hmm, producing a child every 2 years for 20 years...

We 've got different definitions of paradise

Chacal

LOL

This is actually the figure that the final number is most sensitive to.

Every 4 years: 15,932
Every 3 years: 106,661
Every 2 years: 1,725,785
Every year: 253,421,300
Every 10 months: 981,208,094

So culture is really going to affect the population growth

 

[der_kluge]

You made me curious so I put together a quick spreadsheet with the following assumption:

The initial population of 100 people are all 20 years olds.
All adults between 20 and 40 produce a child every 2 years (in pairs, of course)
There is a uniform probability of dying from age 0 to age 100, with an average lifespan of 70 years. Anyone whe reaches age 100 dies.

The final population in 200 years is 1,725,785

Admittedly this is a high upper bound for the population implying that they're living in some kind of paradise, but it does give some idea as to what is possible.

Uh, that's 20 children per family. That's... nigh impossible. At best, I think you're looking at maybe 10 per family, and that's stretching it a bit. Getting pregnant isn't always so easy. Many couples try for years to get pregnant before success.