To defend my original comment I would first look at the Cambrian explosion... in a short period of time "by evolutionary standards" the diversity of life increased immensely.
This is what most people have been taught about the Cambrian, but this is NOT what scientists say happened for about the last 40 years. Isn't that weird? How can people be taught something so outdated which is no longer believed by scientists? Perhaps creationists are interfering with the contents of school textbooks? Do we have evidence of that? Well how about that, we sure do.
The Cambrian lasted about 40 million years, plenty of time for the development of any creature, let alone simple ones like molluscs and arthropods. The diversity did NOT just spring out of no where, because we now KNOW that the era before the Cambrian was absolutely filled with life too. The whole Cambrian Explosion is looking more and more like an illusion created by special fossilization circumstances. In other words, right during the Cambrian, conditions were perfect for fossilization and so we see a surge in the number of fossils and think that life itself surged during this period. But it didn't. More fossils does not equate to more life.
Next, the origin of live itself would require an organism that is able to reproduce, for it to reproduce it first needs to be singular, in other words something has to separate from its environment, Assuming that it was by random chance that life was created... The time it would take not to only create life, but also by random chance an organism that could reproduce is astronomical,
The origin of life began with the first replicator. Reproduction was THE event that started life, everything else followed from that.
then you have the likelihood that many of the first species were killed before they grew to a level of sustainable population.
That first replicator faced no competition and was surrounded by nothing but more raw materials to make copies of itself. It would have dominated the oceans in months.
Irreducible Complexity. Not to say that Irreducible complexity makes evolution impossible.
IC does not exist. It is an illusion caused by looking at the evolutionary process backwards. Lets say a new plague breaks out and some small percentage of humans survive because that have a mutation in their appendix that saves them. Then the survivors breed of course and repopulate. A thousand years later they all think "We must have been created because we can't live without an appendix" and they forget that there was a time when this was NOT the case.