Themis wrote:One wonders why Adam is needed in a world where humans have been running around for many ten's of thousands of years. At least the original story has him as integral as the first human.

Well, it wasn't to be the first human, so much as the first "man."
There are many kinds of humans. Actual spirit sons and daughters of Elohim, on the other hand, are not necessarily just "human." Spirit children of Elohim have "human" bodies to be sure, as DNA shows continuity from our bodies to theirs.
If we analyze the new October 2016 statement in the
New Era, it seems to makes a distinction between regular "humans" (i.e. human bodies inhabited by spirits of whatever) and actual spirit Chidlren of God:
Before we were born on earth, we were spirit children of heavenly parents, with bodies in their image. God directed the creation of Adam and Eve and placed their spirits in their bodies. We are all descendants of Adam and Eve, our first parents, who were created in God’s image. There were no spirit children of Heavenly Father on the earth before Adam and Eve were created. (
https://www.LDS.org/new-era/2016/10/to-the-point?lang=eng)
I don't know how far I would take this in my own personal beliefs. But if one is to go by this new statement, it seems clear here, that the most recent statement on Evolution is drawing a new line in the sand. Even anatomically modern humans are not all literal spirit "Children of God." In theory, those before Adam were not of the literal spirit family of Elohim. Therefore the family of Elohim is not the only kind of humans that can supply human-looking spirits to human bodies. The humans that pre-dated Adam are apparently not spirit children of the Gods, but are also of lesser human orders which come very close, and who have lots of intelligence and are capable even of bronze-age technology, but still apparently are not capable of sin. Once we had Spirit Children of Elohim entering those bodies, then we really had the "temporal" age of the earth, the time of sin on the earth, with spirits capable of it. (D&C 77:6)
The Book of Moses speaks of Adam as the first man of all men. This is clear that it has to do with something Spiritual now instead of something literal for the human race. The human race clearly is comprised of more than one family group of spirits with the form of anatomically modern humans, some being of the race of gods, and some not.