What do you think?
That everything can change completely in a few days?
Evolution is as far as i know/think nothing really "planned" it occurs when copying genetic material. since cells do not use a 100% save system there are always some rare mistakes which lead in an even more unlikely case to a better version of the cell or maybe at first to an even worse version which maybe gets better with a few other mutations.
Well this is what we simulate in GA's but in reality it is a lot slower because in addition we have external factors because one good cell may die in coincidence and the other way round. So it will take really long for one change in one cell to "spread" in the population.

So it is all very likely that most of the good evolutionary developments died but it is a little more likely that the bad developments die.
so over a huge time period and many "tries" you will get a better population.
it is just like the stuff we made in maths some years ago. if you roll a dice around 10 times it seems as if it is not like all sides of it have the same chance to be the upper side but after a huge number of tries you will see that the chances get more and more stable and that's just how it is with evolution. you may get fast to your wanted result or maybe not. but all in all it is a straight continuing process.