Mumbai scientist challenges theory that bacteria came from space

A young Mumbai scientist claims to have disproved a theory that living bacteria from space called Cometary Panspermia could have led to the origin and spread of diseases like SARS Severe Acute Respiratory Syndrome that ravaged many countries in early 2000In his article Critique on Vindication of Panspermia 31yearold Pushkar Ganesh Vaidya of the Indian Astrobiology Research Centre IARC has challenged the theory that three microorganisms two bacteria and one fungus captured from around 41 km above the earth by a team comprising renowned astrophysicist Jayant Narlikar were of cometary origin Vaidyas paper has been published in the latest issue of the wellknown peerreviewed Canadian scientific journal Apeiron Apeiron Vol 16 No 3 July 2009 The three microorganisms were captured through special devices fitted on balloons from earths stratosphere in January 2001 by a team of Indian and British scientists Vaidya said arguing that the microorganisms exhibited no distinct adaptations expected to be seen in the light of the theory of evolution and the concept of niche biology The experiments were conducted by a team which included Narlikar of the InterUniversity Centre for Astronomy and Astrophysics IUCAA Pune and N Chandra Wickramasinghe of the Cardiff Centre for Astrobiology in Britain Subsequently the team put forward the hypothesis that such microorganisms could not travel as high as 41 km above the Earth so they must have come from outer space The experiment was repeated in March 2009 and 12 bacterial and six fungal colonies were found at similar heights According to the hypothesis microbial life was first brought to the earth about four billion years ago by comets and they continue to do so Narlikar even contended that the dreaded SARS virus came from outer space However Vaidya who analysed the characteristics of the three microorganisms found during the 2001 experiment said they did not show any characteristics expected in microorganisms which lived in comets and hence must have originated from earth only Vaidya said the cometary environment is an extreme ecological niche and if microorganisms are to survive in such an extreme environment for over a million years before being deposited in earths atmosphere in a freezedried state then they must adapt accordingly as per Darwins theory of evolution Meanwhile Narlikar said that their research was not intended as a theory but a suggestion for further exploration into this aspect We intended that there should be more research and studies on this subject If somebody has done it it is good he said However in a separate written reaction Narlikar said that he had seen Vaidyas paper and found it somewhat superficial in its reasoning One important aspect missed by the author is that these microorganisms have not come directly from a comet They were trapped in the Earths atmosphere and would take some weeks to remain there as argued by the late Sir Fred HoyleWickramasinghe theory of panspermia he said adding the microorganisms would get used to gravity Arguments against panspermia used to be made on the grounds that they would not survive in the hostile radiation in the interstellar space Experiments at the Hyderabadbased Centre for Cellular and Molecular Biology CCMB have however shown that under doses of radiation like UV Xrays and gamma rays bacteria mutate and learn to survive I think one should be more cautious in rejecting the panspermia hypothesis and do further experimentation on microlife in interstellar space Future work on cometary material will throw light on this issue The author Vaidya rejects the panspermia hypothesis but has no suggestion as to how the microorganisms got there from the earth he said The paper was rejected by reputed journals in astrobiology several times and hence has found a place in a nonspecialist magazine Narlikar added On the other hand Vaidyas mentor and biologist Arun Dholakia said the entire panspermia theory would now change or have to be rewritten However he said it would take some time before the scientific community comes to terms with Vaidyas research But I am happy that at least a debate has been initiated and the outcome would only benefit science and the scientific community he said