All sciences can be confusing if you don't have enough patience & persistence to study them carefully.
Tontokowalski: "I've read studies that say all humans originated in Africa, some say that other populations rose outside of Africa.
Some say Neanderthal breeding with European populations of early man led to further genetic mutations distinguishing them significantly (and for the better) from populations that did not leave Africa."
There are many hypotheses, and more than one theory, about how pre-humans and early humans developed, migrated and interbred.
Over many years, each new discovery and each new interpretation of old data, has brought one model or another to the forefront of discussion.
If you take the time to bone up on past ideas, then watching new ones unfold can be more interesting.
My point is, these theories are all fascinating, but don't grow too attached to any one of them, because there's every chance over the long term, it'll be overturned.
Tontokowalski: "I think the trend now is that there is no such thing as 'race.' "
What are commonly called "breeds" or "varieties" in nature, we call "race" in humans.
Neanderthals are today thought to be certainly human, but of a different sub-species, meaning still able to interbrede, but not as close as other modern human "races" / breeds.
Tontokowalski: "I don't understand what studies might be slanted because of a desire to separate from African origin, and which may be truth that is being deliberately downplayed because some scholars don't want non-Africa origins."
As of today you can be sure there are some scholars somewhere who defend every recent hypothesis / theory.
"Out of Africa" seems well enough confirmed to withstand an occasional outlier data point, such as these teeth.
But what is not clearly understood is how much interbreding went on amongst the many & various pre-human sub-species and breeds.
So, for more data on that, stay tuned...
Tontokowalski: "Even more unsettling is that both seem to be flatly stated as 'truth' without regard to other possibilities."
No, now you are reading in words which are almost never used in scientific reports -- words like "truth" and even "facts".
Instead, they talk of "evidence" which "suggests" or is "consistent with" or "confirms".
By its nature, science is not so much about "truth" as it is about hypotheses and theories, which are fancy words meaning models, unconfirmed and confirmed.
It was interesting.