How plausible is the following statement with respect to various events in the history of life on earth?
Random mutation and natural selection, together with other known natural mechanisms and environmental events adequately explain "X".
For X, fill in the following, and then state the plausibility of each (10 = highly plausible; 0 = highly implausible):
1. microevolutionary changes, such as bacterial resistance
2. minor macroevolutionary events such as the appearance of varieties of beetle species with no significant morphological changes.
3. minor macroevolutionary events such as the appearance of horses and zebras from a common ancestor.
4. moderate macroevolutionary events such as the appearance of horses, cows and sheep from a common ancestor.
5. macroevolutioary events such as the emergence of whales and bats from a common mammal ancestor.
6. the Cambrian Explosion (the apparently sudden appearance in the fossil record of many complex, multicellular animals, dated at about 540 million years ago).
7. the origin of life itself- the first appearance of life on earth.
Please comment! I will wait for some comments before giving you my answers. Feel free to describe yourself when you give your answers in whatever way would be of interest to readers. I may tweak the survey if there are comments that convince me that it can be improved significantly, but I will put any significant changes in a new post.
I encourage links to this survey, as I am genuinely curious to see how others evaluate the evidence.
Update: I revised number 2 to clarify that I was referring to varieties of beetle species with no significant morphological changes.