Unlikely.
and now our ancestors may not have all been as ape-like as we once thought?
Where do you see *that* in the above article? You might want to reread it.
Is there nothing left we can rely on with any degree of certainty?
Yes -- you can rely on science giving the best analysis of the mountains of currently available evidence, as science will always adjust itself to match what the evidence indicates. Usually these are small adjustments, as in the above article (contrary to those here who try to falsely portray it as some sort of "we were all wrong before"). Even once in a very long while there are large adjustments, but even these are usually extensions to existing theory, not replacements. For example, Relativity extended Newtonian physics to the realm of velocities close to the speed of light, but Newtonian physics was not "overturned" -- it's still perfectly valid for the vast majority of physical analysis.
On the other hand, we have the supernaturalists who say, "if all the evidence indicates something other than what we have in this ancient book, we will ignore the evidence."
With this kind of constant, drastic "evolution" of theory you have to admire those who continue to place all of their faith in science.
Your impressions of "constant, drastic" change in the theory of evolution is grossly unfounded. All of the principles that Darwin laid out for his theory in 1859 are still standing. What has changed is details like whether species X descended from species A or B, where A and B are themsleves very closely related.
God bless 'em!
Why thank you.