Where does life come from?
Thursday 15th March 2012 @ 19:00
Member: £5.00 ; Member's Guest: £8.00 ; Non-Member: £10.00 ; Staff: £3.00 ; Student: £3.00
Dr Zita Martins, Royal Society University Research Fellow, Imperial College London
“I’m trying to answer two questions. How did life start on Earth? And are we alone in the universe?"
Paul Garwood reports on the lecture and Zita Martins' findings.
We know there were simple molecules on the early Earth that evolved to more complex structures. Then there was a jump where nobody knows what happened, and we had life.”
Dr Martins is an astrobiologist at Imperial College where she has been looking for particular molecules in 4.6 billion year old meteorites, of a similar age to the solar system. She recently discovered extra-terrestrial organic molecules that might indicate that life is far more widespread in the universe than hitherto thought. In a sample from the Murchison meteorite, that landed in the Sixties in Australia, she discovered that organic compounds, which are components of the genetic code in modern biochemistry, were already present in the early solar system and may have played a key role in life's origin.
Dr Martins has presented a number of radio and television programmes about the origins of life on earth and the likelihood of its presence elsewhere in the Universe.
Paul Garwood reports on the lecture:
What happened in the late summer of the Cosmic Calendar? Dr Zita Martins posed the question to a packed house of 300 or so at a lecture organized by Friends of Imperial College on 15 March. Using Carl Sagan’s Cosmic Calendar, Dr Martins focused on what happened between “August”, when the Solar System was born, and “October”, when life first appeared – all en route to the appearance of multi-cellular organisms in November and mankind on “31 December”!
She explained that the Oparin/Haldane “primordial soup” theory of the 1920’s looked like a strong contender. But work in the 1950’s showed that the lightning that was supposed to spark life from the primordial soup was not prevalent in the early atmosphere. Dr Martins then introduced the possibility of incoming meteorites and comets bringing certain molecules that, in whole or in part, then expedited the development of life on earth.
She made a very strong case based on her own and other work on the content of various meteorites. Not only did this work find amino acids (the building blocks of proteins), nucleobases (components of DNA and RNA), plus other complex organic items, but it also demonstrated the very low probability that the specific molecules found could have come entirely from contamination.
I well recall my fumbling attempts at analytical chemistry in the IC chemistry labs several decades ago. This sometimes involved whole test tubes full of single materials which I could only identify with great difficulty. The most striking thing for me in this part of the presentation was the extent to which technology now allowed the identification and quantification of dozens of individual materials – all from a sample of only a tenth of a gram! Quite apart from the technological kit required to enable this, the meticulousness required of the researcher, to eliminate all sources of potential contamination, and interpret the data output, was hugely impressive.
So, it looks likely that some form of “exogenous” source played at least a part. But that still leaves a lot of the puzzle to unravel. What exactly was the course of events during that late Cosmic Calendar Summer? And where did those exogenous molecules come from and how were they produced there? And, the really big question, does this all give us new insights into whether we are alone in the Universe?
Some of these questions may never be answered with any degree of confidence. However, if people of the calibre of Dr Martins are working on it, then we are certainly in with a chance! During her one hour lecture, and the Q&A that followed, she demonstrated an outstanding level of competence and an extraordinary ability to communicate complex ideas with real simplicity. It is no wonder that she has been a regular guest on scientific broadcasts.
This was even more remarkable as she was operating in a second language. Dr Martins took her first degree in her native Portugal and her PhD in astrobiology in the Netherlands. (I note with amusement that when I was at College, “astrobiology” would probably have been thought to be an obscure branch of tarot card reading!). A period at NASA in the USA followed, and an associateship at IC. Dr Martins is now a visiting professor at a University in France and the Royal Society University Research Fellow at Imperial.
Altogether this was another outstanding evening organized by Friends of Imperial College – an organisation dedicated to spreading enthusiasm and knowledge of science, technology and medicine. It is independent of, but linked to, one of the premier scientific establishments on the globe and arranges a programme of lectures and events to spread knowledge and stimulate attention to scientific developments. It can be contacted via www.friendsofimperial.org.uk. Membership is open to all.
Forthcoming Friends’ events include an Oddities of Physics session at 12 noon on Saturday 12 May 12 at the Imperial Festival, and a lecture on Plastic Electronics by Prof Donal Bradley at 7pm on Tuesday, 15 May.
There are also two Members only (and their guest) visits. A Behind-the-Scenes visit to the Lifelong Health Project at Imperial College on 18 April, and a visit to the Rutherford-Appleton Laboratory at Didcot on 10 May.
Venue: Lecture Theatre G16, Sir Alexander Fleming Building, Imperial College Road SW7 2AZ
Campus Map reference 33
on the Imperial College Map