Question

What is the most recent evidence suggesting that all life on earth shares a common ancestry?

Answer 1

It was originally Charles Darwin who proposed the idea of a common ancestor for all life on Earth. However he couldn’t scientifically prove his hypothesis as DNA was not discovered during his time. Douglas Theobald, assistant professor in biochemistry of Brandeis university, has chosen 23 proteins that are universally conserved across the three domains of life – bacteria, archaea, and eukaryotes and had run statistical analysis on the amino acid sequences of these conserved proteins. He performed various relational and evolutionary model studies on these sequences and concluded that a universal common ancestor is at least 10^2860 likely to have produced the variances observed in the modern day protein sequences rather than the multiple separate ancestors.