Origin & Evolution of Life: August 2021

In evolutionary biology, tracing back ancestral genetic elements is a quest in reconstructing the history of life on earth. The presence of similar or "homologous" genes in different species speaks of shared ancestry and of past molecular events that led to diversification from a common ancestor, ultimately leading to speciation.

The history of life on Earth has often been likened to a four-billion-year-old torch relay. One flame, lit at the beginning of the chain, continues to pass on life in the same form all the way down. But what if life is better understood on the analogy of the eye, a convergent organ that evolved from independent origins? What if life evolved not just once, but multiple times independently?

Perhaps the most fundamental puzzle in biology - "What is life?" - is addressed in a new paper by Planetary Science Institute Senior Scientist Oleg Abramov.

Nitrogen is vital for all forms of lifeĀ¬: It is part of proteins, nucleic acids and other cell structures. Thus, it was of great importance for the development of life on early Earth to be able to convert gaseous dinitrogen from the atmosphere into a bio-available form - ammonium.