but the chance of that is very low. if the chance to evolve a single part is say 1 in a billion mutations,
Let's go with the 1 in a billion chance that you pulled out of your behind.
Let's say we have a population of 1 million, a generation cycle of 1 day and a mutation rate of 10.
So on day 0, we have generation 1: an immobile population of 1 million.
Day 1, generation 2: 10 million mutations.
Day 10: 100 million mutations.
By day 100: 1 billion mutations.
Probabilistically speaking, the first part is now evolved.
The point: no matter how unlikely something seems - the very nature of probability is that stuff eventually inevitably will happen given enough test tubes.
then the chance to get about 3 parts at once is 10^27. if we are talking about mammals we will need more then the age of the universe for a single new system.
Only if completely forget about natural selection, inheritance, the fact that populations include more then 1 individual,.................................... and off course, if you ignore that you are making up your "facts" on the spot, like usual.
In other words: only in your fantasy land between your ears.