A mutation is a change nucleotide sequence of DNA, these nucleotide sequences are what code the genes and genes are what determines you height, eye color how many finger you have whether you have 2 arms and 2 legs and so on.
Mutations can have positive negative or no effects. Most mutations are neutral (have no effect), some are negative (decreasing an organisms chances of survival and reproduction) and some are positive (increasing an organisms chances of survival and reproduction).
That brings me to natural selection
Where mutation is random, natural selection is not.
As I said mutations can be positive or negative, positive mutations increase an organism chances of survival and reproduction and thus the chances of passing on these positive mutations to the next generation, negative mutations decrease an organism chances of survival and reproduction and thus the chances of passing on these negative mutations to the next generation. Over generations the positive mutations build up in the population while negative mutations are weeded out.
This is natural selection.
Genetic drift is random mutations that build up over time in a population resulting in changes in the genetic makeup of the population.
Links and sources
Mustation
Natural Selection
Gentic Drift
Part 5
Part 7
Evolution main page
These genetic markers are very useful in piecing together history because it adds another nugget of information on who moved where and when.
[...] population (breeding between the (now) two population limited to none) then through the processes of mutation natural selection and genetic drift the populations evolve separately until it becomes imposable for the two populations to interbreed [...]
[...] 1. Evolution part 6: Mutation, natural selection and genetic drift 2. The Rise of Antibiotic-Resistant Infections 3. the history of nylon 4. Utilization of a Cyclic [...]
[...] 1. Evolution part 6: Mutation, natural selection and genetic drift 2. The Rise of Antibiotic-Resistant Infections 3. the history of nylon 4. Utilization of a Cyclic [...]
[...] (breeding between the (now) two population limited to none) then through the processes of mutation natural selection and genetic drift the populations evolve separately until it becomes imposable for the two populations to interbreed [...]
[...] weeded out by natural selection. And even with modern medicine natural selection still apples.[see Part 6 and 7] And the traits that lead us to create these medicines to help the sick and that lead us to [...]
[...] Part 6 Part 8 Evolution main page [...]
[...] further it is demonstrable that life not only reproduces but reproduces with variation which natural selection acts upon (evolution). But how did life start? We don’t have a full understanding of [...]