https://www.churchofjesuschrist.org/general-conference/1977/04/come-know-the-lord-jesus?lang=eng

In due course came Adam and Eve; the fall of man, with its temporal and spiritual death…

https://www.churchofjesuschrist.org/general-conference/1979/10/the-mystery-of-mormonism?lang=eng

It called for the fall of Adam so that temporal and spiritual death would enter the world and pass upon all men.

It called for an infinite and eternal atonement—wrought by One who would be the Only Begotten in the flesh—which atonement would ransom men from their fallen state.

https://www.churchofjesuschrist.org/general-conference/1980/10/the-lord-god-of-the-restoration?lang=eng

We know and testify that mighty Michael foremost fell that mortal man might be, and that “the Almighty God gave his Only Begotten Son” (D&C 20:21) to ransom men from the temporal and spiritual death brought into the world by this fall of Adam.

https://www.churchofjesuschrist.org/general-conference/1981/10/who-hath-believed-our-report?lang=eng

to ransom men from the temporal and spiritual deaths brought into the world by the fall of Adam.

https://www.churchofjesuschrist.org/general-conference/1984/10/the-caravan-moves-on?lang=eng

I propose some simple tests that all of us may take to determine if we are true to the faith. They consist of a few basic questions, all of which must be answered correctly in order to gain the full blessings of the gospel in this life and inherit eternal life in the realms ahead.

…

From among many questions that all of us must one day answer, let me test you on these:

Test two: Do I believe in the fall of Adam?

There is no salvation in a system of religion that rejects the doctrine of the Fall or that assumes man is the end product of evolution and so was not subject to a fall.

True believers know that this earth and man and all forms of life were created in an Edenic, or paradisiacal, state in which there was no mortality, no procreation, no death.

In that primeval day Adam and Eve were “in a state of innocence, having no joy, for they knew no misery; doing no good, for they knew no sin.” (2 Ne. 2:23.)

But in the providences of the Lord, “Adam fell that men might be; and men are, that they might have joy.” (2 Ne. 2:25.)

By his fall, Adam introduced temporal and spiritual death into the world and caused this earth life to become a probationary estate.

There is no question about what Bruce R. McConkie personally believed on the topic.

In his CES Symposium on the New Testament he discussed how the sealed portion of the Book of Mormon would destroy the entire theory of evolution:

As of now, the world is not ready to receive these truths [found in the yet to be revealed sealed portion]. For one thing, these added doctrines will completely destroy the whole theory of organic evolution as it is now almost universally taught in the halls of academia. For another, they will set forth an entirely different concept and time frame of the creation, both of this earth and all forms of life and of the sidereal heavens themselves, than is postulated in all the theories of men. And sadly, there are those who, if forced to make a choice at this time, would select Darwin over Deity. (emphasis added)

In his speech at BYU entitled The Seven Deadly Heresies, he stated:

Heresy number two. There are those who say that revealed religion and organic evolution can be harmonized. This is both false and devilish….

Try as you may, you cannot harmonize these things with the evolutionary postulate that death has always existed and that the various forms of life have evolved from preceding forms over astronomically long periods of time. …

Note that after giving the speech, Bruce R. McConkie was forced by Spencer W. Kimball to soften his rhetoric somewhat, resulting in the speech that has now been officially published by the Church.