ID No.: 2011HZ67002
NAME OF THE STUDENT: Kanwaljeet Kaur
DISSERTATION TITLE: Biology and Information
ABSTRACT
The concept of information has gained prominence over the past six decades in biology. Informational descriptions can now be found within modern genetics, molecular and cell biology, evolutionary biology, systems biology and philosophy of biology. Nevertheless, there are serious ongoing debates over the legitimacy of the term “information” in biology. This thesis will review the history of this important debate and its current status within modern biology.
The term “information” was originally introduced by Ephrussi et al. in 1953 as a way to unify the three terms referring to bacterial sexual reproduction, viz transformation, induction and transduction. However, the term did not have any explanatory significance by its own. Soon thereafter, Crick introduced the term “information” in biology in an explanatorily significant manner via “The Central Dogma of Molecular Biology”, to account for the observed uni- directional flow of biochemical processes from DNA to RNA and RNA to synthesis of proteins. The notion of genetic information was born and got repeatedly invoked to explain the role of genes in the expression of the phenotypic traits of the whole-organism, i.e. genetic determinism, in conceiving genes to have a program stored for the development of an organism as well as in the inheritance of observable characters and in evolutionary theorizing.
Living organisms contain another type of information in the nuclear structures other than DNA and RNA, and other cellular structures which co-determine the course of molecular and developmental processes of an organism. This type of information is called “epigenetic information”. The role of epigenetic information has also been a subject of investigation.
The treatment of genes as a carrier of meaningful information, i.e. the DNA as having a property of intentionality, has become appealing to both contemporary philosophers and biologists. Some biologists assign a causal role in generating meaningful information to natural selection. The use of the concept of information has been extended to cell signaling mechanisms.
Nevertheless, other biologists have questioned the very legitimacy of the application of informational concepts in biology. They argue that, for example, an interaction between a particular nucleotide base sequence and an amino acid can be explained solely as a biochemical reaction, without invoking any appeal to “information”. Biologists who oppose the use of information in biology label such accounts as being only linguistic metaphor, bringing no explanatory content of its own. Sarkar believes that there is no clear technical notion of “information” in biology, and that molecular biology would always in its whole history have been better off, if it had not adventured into the informational analogies. Another line of opposition from Oyama, Griffith and Sterelny has been against the use of genetic information in molecular genetics to reinforce genetic determinism.
This contemporary debate over information is crucial to future directions in biology. Biology, as a matter of fact, concerns the study of life. The most fundamental questions that can be asked in biology are, “What is life?”, and “What is the origin of life?” Many hypotheses have been formulated to answer these questions. The discoverers of the DNA expressed the hope that an understanding of the genetic functioning in terms of information contained within would help in addressing the question of what life is.
