JOEL - From everything that I have learned on the subject, Jesus is literally and physically the Son of God. The biological explanation of exactally how Mary conceived is something only God and Mary could know. We have never specifically been told the details and I know of no prophet who ever asked God about it and got a specific answer. I have read all the quotations that were cited by White. Most of them don't specifically imply that a "traditional" physical relationship between God and Mary brought about the conception of Jesus; some of them do. The ones that do, were clearly the opinions of the authors, even if they were leaders of the Church at the time they said it.
We learn from the scriptures that the Holy Spirit in some miraculous way unknown to mortals, prepared Mary so that she could endure the presence of God when Jesus was conceived. "The Holy Ghost shall come upon thee, and the power of the Highest(i.e. God the Father) shall overshadow thee: therefore also that holy thing which shall be born of thee shall be called the Son of God." (Luke 1:31-35.) From this scripture we know that God, "the Highest" (Luke 6: 35-36), was definitely present when it happened, and that conception occurred when His power "overshadowed" her. The question is, what does "overshadow" mean? We may never know, but God, being all powerful, was certainly capable of placing His seed in Mary in ways other than that used by mere mortals. Mary was still considered a virgin afterwards since virginity is a concept confined to earthly human beings and can only be violated by an earthly man.
Elder James E. Talmage, a past authority of the LDS Church, has written: "That Child … born of Mary was begotten of Elohim, the Eternal Father, not in violation of natural law but in accordance with a higher manifestation thereof; and the offspring from that association of supreme sanctity, celestial Sireship, and pure though mortal maternity, was of right to be called the 'Son of the Highest'" .
Personally, I don't really care how it happened. Most important to me is that it did happen and that Jesus is the Son of God and my Savior.