In another thread a discussion of generation time emerged and I made a statement that we don't want to look only at the average age at which a mother gives birth, because earlier births cause more growth than is "lost" to late births.
I'm not sure if that makes sense, and spending a couple of minutes trying to model it I started to think I may actually be wrong here.
Here's two simple models, and for simplicity (I don't think it changes the point) let's assume cloning. Also assume all children survive and produce children at the same rate.
Model 1: Each mother gives birth at age 30 to a litter of 3 children.
Model 2: Each mother gives birth to 1 child at age 20, 1 at 30, and 1 at 40.
After say 500 years will the populations of these two models differ? They both have the same mother's average age of giving birth, but just intuitively it seems like those children who are born after 20 years and thus start giving birth to more kids early will have a disproportionately large effect on the total population later in time.
Am I wrong? I could just add up all the kids in each generation but that's a lot of work and it's not clear to me how to simply calculate the total population after x years in the second model.
My poor math skills are showing. :blush:
I'm not sure if that makes sense, and spending a couple of minutes trying to model it I started to think I may actually be wrong here.
Here's two simple models, and for simplicity (I don't think it changes the point) let's assume cloning. Also assume all children survive and produce children at the same rate.
Model 1: Each mother gives birth at age 30 to a litter of 3 children.
Model 2: Each mother gives birth to 1 child at age 20, 1 at 30, and 1 at 40.
After say 500 years will the populations of these two models differ? They both have the same mother's average age of giving birth, but just intuitively it seems like those children who are born after 20 years and thus start giving birth to more kids early will have a disproportionately large effect on the total population later in time.
Am I wrong? I could just add up all the kids in each generation but that's a lot of work and it's not clear to me how to simply calculate the total population after x years in the second model.
My poor math skills are showing. :blush:
via International Skeptics Forum http://bit.ly/2wqK0gY
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