Some Problems in Proving the Existence of the Universal Common Ancestor of Life on Earth

<table>Independent origins hypothesis versus common origin hypotheses of <i>cytb</i> and <i>nd2</i>. No branch exists connecting the two genes in the independent origins hypothesis, while the common ancestor of the two genes exists in the common origin hypothesis.</table>

The Scientific World Journal

fig1

Figure 1

Figure 1: Some Problems in Proving the Existence of the Universal Common Ancestor of Life on Earth 