There are 2 Trees of Life
PICK ONE
1) The evolutionary tree of life.... both cladistic & descriptive usually rely on synapomorphies (traits which define a branch but suffer from problems of homoplasy). Also, some evolutionists point out that HGT (horizontal gene transfer) has scrambled the evolutionary tree of life so bad that it should be scrapped altogether.
2) Biblical Tree Of Life... would explain a special fruit which likely renewed the telomeres of cells to keep a human living in their prime as long as they ate from it. Therefore continuing life as long as you had access to it.
And the LORD God said, Behold, the man is become as one of us,
to know good and evil: and now, lest he put forth his hand,
and take also of the tree of life, and eat, and live for ever:
Genesis 3:22
To him that overcometh will I give to eat of the tree of life,
which is in the midst of the paradise of God.
Revelation 2:7