The most important question that the science is trying to answer for a long time is: " How did life on hearth begin? What was the initial spark that lits the fire of evolution? Perhaps today thanks to a research of five researchers at Arizona State University and UC S.Cruz, directed by Sandra Pizzarello Italian, Venetian, and Professor Emeritus at the Dpt. of Chemistry & Biochemistry at ASU, has discovered an important aspect, that the origin of the life could have been aided by the exogenous delivery of meteorites. We have asked Professor Sandra Pizzarello to tell us of her discovery.
The professor, before starting the interview, underlines two important points: firstly the meteors cross the atmosphere without reaching the earth, while the meteorites came in to the earth floor . secondly , nobody affirms that the life is “ brought” from the meteorites, but only its possible ingredients.
Professor Pizzarello :what are the constituent elements in your research that gave a clue in how life could have been aided by meteorites?
The idea that exogenous delivery of organic molecules could have aided molecular evolution and the origin of life is indeed old and, as it relates to meteorites, it goes back to the unequivocal finding of amino acids in the Murchison meteorite in 1970 (Kvenvolden et al., 1970, Nature 236, 66).
which are the first chemicals constituent elements to produce the Dna, the RNA and proteins?
We do not know and I took pains in the article’s Introduction to emphasize out little we know about the origin of life (and the origin of RNA is part of that unknown)
In your search you speak of Ammonia as essential element for the life, can you explain what is and because it’s so important?
Nitrogen is an indispensable ingredient for the formation of the biopolymers on which life depends (proteins, DNA and RNA). Any theory that tries to explain biogenesis has to account for a supply of reduced (reactive) nitrogen. Ammonia has been a bit elusive to fit in these theories. It was easy to envision when the early Earth atmosphere was believed to be reducing, (e.g., it could have provided ammonia and amino acids by Miller-type reactions) but it is not so for the current understanding of a neutral or mildly oxidizing early atmospheres. The direct delivery of relatively large amounts of ammonia is prebiotically very, very attractive.
If the life evolved from meteoritic compounds, can we say that we originate from the space?
Chemically, yes, just think that the Big Bang produced only hydrogen, some deuterium (heavy hydrogen) and a bit of lithium. We are made of C, N, O, S, and P besides H and all these elements used in biochemistry were formed in the caldrons of stars during what you could call chemical evolution during a long cosmic history.
Can exist other forms of life therefore?
Your guess is as good as mine.
How did you approach to study meteorites? how and where your scientist life begin ? in Italy?
I gew up and studied in Italy but my scientific career started in the USA.
Which have been the reactions of the NASA after your research?
I have not seen their newletter yet, it should mention this work.
Emeritus Professor and Research Professor : Research and Teaching Interests
My research of over thirty years has been devoted to the study of the organic material in carbonaceous chondrite meteorites, with emphasis on the molecular, isotopic, and chiral characterization of their soluble compounds. More recently, it has focused on the study of the non-racemic amino acids of meteorites, with compound specific isotopic analyses as well as model syntheses that would mimic their prebiotic catalytic activity and reactions.