JOEL - I assume you mean, how do I know that what I feel as I receive inspiration from the Spirit is not just some biological reaction; such as a response to a piece of uncooked potato, as Ebenezer Scrooge once said. Perhaps the Spirit does use biochemical reactions as its method to effect that unique feeling we get when it's trying to tell us something. I do know that the only time I feel it is after I have humbled myself before the Lord and have fasted and prayed sincerely about something important. I feel it after reading the scriptures; while listening to an inspirational talk; or while attending the Temple. If it is a biological reaction it sure seems to be restricted to those types of situations. The power of the priesthood can be used to affect biological reactions as well when someone is healed during an administration. Perhaps the Spirit can work that way as well to cause us to feel its influence. It does seem to be more than that however when you consider the comfort and peace that comes over a person's mind and soul.

TOM - How does one explain the incompatability of Native American DNA with Israelite DNA?

JOEL - One is Native American and the other is Israelite. No one knows for sure which of the many tribes of Native American indians are the descendants of the Book of Mormon Lamanites. Perhaps none of the existing tribes are. Most Book of Mormon scholars agree that the Book of Mormon history probably occured in a rather small area of land somewhere in the western continent. How much of the Israelite genes could have survived after centuries of intermixing the blood of the original surviving Book of Mormon Lamanites with other groups that may have come along before and after?( See this page). It is also possible that the true descendants of the Lamanites may have all died out long before the ancestors of today's known tribes came along.
There is a fairly good article that points out a possible connection with comparisons of mitochondrial DNA at Jeff Lindsay's site:

TOM - If the Church is true, why is it so boring?

JOEL - Are you kidding? That is one of the most convincing proofs that the church is true. If someone were trying to make up a religion all on their own, do you think they would come up with something boring on purpose? A lot of it depends on our attitude and commitment to live the gospel, and the strength of our testiomny. If we are truely converted to the gospel we will "hunger and thirst after righteousness" (Mat 5:6). If we do what Alma has suggested.....

"And now behold, I ask of you, my brethren of the church, have ye spiritually been born of God? Have ye received his image in your countenances? Have ye experienced this mighty change in your hearts?" (Alma5:14)

... there is less chance of getting bored.

TOM - When blacks receive their patriarchal blessings, in general what lineage are they told they belong to? (ephraim, manassah, benjamin, etc?)

JOEL - Patriarchs pay no mind to the ethnicity of the one receiving the blessing. They are guided by the spirit to pronounce the lineage. Whether it is a pronouncement of blood inheritance or of adoption does not matter (see Abr. 2:10). Which ever one is chosen it is seen as the line and legacy through which one's blessings are transmitted. It is hard to specify lineage simply by blood inheritance, because the house of Israel today constitutes a large measure of the human family who have descended from the ancient tribes that intermixed one with another. Here are a few quotes that might help:

“A vital part of every patriarchal blessing is the declaration of lineage. … The patriarch should be responsive to the whisperings of the Spirit as he identifies lineage and the special promises and blessings attendant thereto. … The declaration of lineage is to come by the promptings of the Holy Ghost. This inspiration can come to the patriarch regardless of the race or nationality of the person receiving the blessing.” (Information and Suggestions for Patriarchs, p. 4)

The great majority of those who become members of the Church are literal descendants of Abraham through Ephraim, son of Joseph. Those who are not literal descendants of Abraham and Israel must become such, and when they are baptized and confirmed they are grafted into the tree and are entitled to all the rights and privileges as heirs.” (Doctrines of Salvation, 3 vols., Salt Lake City: Bookcraft, 1954-56, 3:246.)