coyote
"Again, it's not linear."
And I am not contending that evolution is alleged to operate in a linear manner. The overall direction must be one way (higher levels of organization) but evolutionary theory allows for accelerations and decelerations.
My point is that over 1.5 billiion or so years, evolution must make progress toward the goal of 6 billion chems in the right slot and the average rate that must be maintained can be calculated.
If a teacher has 30 papers to grade and it is 4 days until grades are due, the teacher must maintain an average rate of grading 7.5 papers a day. This does not mean the teacher sits at his/her desk and grades papers for the entire 4 days. The teacher can grade a few in the morning and a few more at night. The teacher can even skip a day. The only critical thing is to maintain the overall average rate of 7.5/day.
Slower some times, faster others, but evolution must always be moving toward higher levels of organization all the time.
There is not enough time, even with 1.5 billion years. Even speeding up and slowing down, there is not enough time.
There is no where near enough time.
Whether evolution is hypothesized to behave in a linear manner or in spurts, there is no where near enough time.