Evolution 101
Created | Updated May 7, 2005
This is a direct lift from "Darwin's Watch" by Messers Pratchet, Stewart and Cohen, and summarises the basic idea Darwin came up with:
1. Organisms, even those in the same species, are variable. Some are bigger than others, bolder than others, or prettier than others.
2. This variability is to some extent hereditary, passed on to off-spring.
3. Unchecked population growth would quickly exhaust the capacity of the planet, so something checks it: competition for limited resources.
4. Therefore as time passes, the organisms that do survive long enough to breed will be modified in ways that improve their chance of surviving to breed, a process called natural selection.
5. Ongoing slow changes can lead, in the long run, to big differences.
6. The long run has been very long indeed - hundreds of millions of years, maybe more. So by now those differences can have become huge.
1. Organisms, even those in the same species, are variable. Some are bigger than others, bolder than others, or prettier than others.
2. This variability is to some extent hereditary, passed on to off-spring.
3. Unchecked population growth would quickly exhaust the capacity of the planet, so something checks it: competition for limited resources.
4. Therefore as time passes, the organisms that do survive long enough to breed will be modified in ways that improve their chance of surviving to breed, a process called natural selection.
5. Ongoing slow changes can lead, in the long run, to big differences.
6. The long run has been very long indeed - hundreds of millions of years, maybe more. So by now those differences can have become huge.
