1) what alternative explanations are there?

I don't know.

2) what objective evidence is there which is more consistent with the alternative explanation(s) than it is with Dawkins' explanation?

I don't know.

So let's say there is currently no alternative explanation. Does that mean I am supposed to accept Dawkins' hypothesis?

1) what alternative explanations are there?

2) what objective evidence is there which is more consistent with the alternative explanation(s) than it is with Dawkins' explanation?

To me, if you have an explanation that accounts for the observed phenomena in a reasonable manner without significant lacunae or inconsistencies, and no one else has an explanation that accounts for the same phenomena (or a superset of the phenomena) more concisely and/or elegantly and/or with fewer lacunae/inconsistencies, then it seems reasonable to say, "This is the best explanation we've found so far."

I agree. The problem comes if you want to go further than this and expect people to treat the best explanation as one that truly reflects what happened.

I don't really grasp the concept of "converting a hypothesis into a belief about history" and I'm unsure where such a practice belongs in science.

You obviously grasp it, as the following is your rationale behind such a conversion:

The scientific method, as I see it, is among other things a kind of feedback mechanism, and the successive approximation seems to me to be the wisest approach. Science should be less a matter of "this is history" and more a matter of "this is the best explanation we've found so far." But assuming that history is an objective reality, and that science can approach it, won't that ultimately result in convergence on the actual history?

Intuitively, it would seem so. But at what point does the "approximation" get close enough to history that we can declare it actual history?

If we find the explanation that accounts for the observed phenomena in the most reasonable manner, most concisely, with the fewest lacunae and inconsistencies and the greatest elegance, is that not the most reliable means available for "converting hypothesis to history"?

If we "find?" You are assuming the ability to step back from everything and make a passive, objective assessment. Most reasonable. Most concise. Fewest lacunae and inconsistencies. Greatest elegance. Those are all judgment calls largely indebted to intuition. What's more, in the 1980s, the notion that microsporidia were primitive organisms would have passed your test with flying colors. Yet it was wrong.

Let's deal with Dawkins' hypothesis about the evolution of hairlessness. Do you expect everyone to embrace the hypothesis as a truth statement about our history?

I still don't see that you're taking into consideration the idea of weighing hypotheses in the light of their consistency with verifiable, objective evidence (as opposed to weighing them solely in the light of dogmatic beliefs and/or personal opinions and/or psychosocial pressures unrelated to actual scientific merit).

You can weigh hypotheses in light of their consistency with verifiable, objective evidence. But what does that mean? Say we have three hypotheses about history "“ A, B, and C. Hypothesis A is consistent with 4 facts, Hypothesis B is consistent with 6 facts, and Hypothesis C is consistent with 8 facts. Is Hypothesis C history? Or is it merely the best, currently supported hypothesis? Also, competition between A, B, and C is a competition between what our limited mentalities can envision, where neither A, B, or C may reflect history as it was.

Furthermore, I'm not sure there is such an animal as "verifiable, objective evidence." Data are verifiable and objective, but to convert data into evidence, we require concepts that interpret the data such that our minds "see" evidence. If you can't get your mind around a concept, you won't ever see how data relates to it as evidence.

Let's try a different tack. Just for the sake of argument, let me go to the opposite extreme, and claim that all scientific conclusions are equally valid, and that each of us should just believe whatever seems right in his own eyes, and nobody should tell anyone else that their view is not scientific. After all, there's no objective criteria for determining what happened in the past "“ and the past begins with the passing of each moment of the present, so technically it's all in the past.
What's wrong with my view?

Yes, that's the other extreme. What's wrong? All views are not equally well supported or equally deficient. But the issue is not about things being equal or supported. The issue is at what point do we convert a hypothesis into a belief about history.

Let's try a different tack. Just for the sake of argument, let me go to the opposite extreme, and claim that all scientific conclusions are equally valid, and that each of us should just believe whatever seems right in his own eyes, and nobody should tell anyone else that their view is not scientific. After all, there's no objective criteria for determining what happened in the past - and the past begins with the passing of each moment of the present, so technically it's all in the past.

What's wrong with my view?