Gene: From Demarcation to Dynamic Meanings

Without doubt the noun gene is one of the most important words in life sciences. From its very introduction it has held a certain ambiguity and uncertainty. Both scientists and philosophers have attempted to reveal the nature of a gene. However, despite the abundance of attempts to clarify the definition, we might not actually need to unite the various suggested definitions into one. As Evelyn Fox Keller has pointed out (2000: 139–41), the ambiguity of this noun makes communication between scientists from diverse disciplines far easier, because it enables them to refer to slightly different entities using a single term. Since it is much more difficult for scientists from different disciplines and with different perspectives to use exactly the same definition, such ambiguity is critical for fruitful communication. In addition, this noun has greatly contributed to forming a synthesized view of life. Indeed, it is critical for perceiving biology as a whole. However, Keller warns us that it also gives us a certain incorrect perspective on the nature of life phenomena by making us view genes as entities that ontologically precede cellular systems—in other words, as independent and separable elements contained within the cell. Keller's concern seems plausible, because genes never exist independently of their environment. At the same time, however, there are certain situations in which we should consider these environment-dependent entities as independent, or, more accurately, in a state of "epistemic independency." To support Keller's point, in this essay I argue that genes are neither ontologically nor epistemically independent. First, I briefly point out two reasons for the apparent independency of genes. Second, I refute their ontological independency. Then, I argue that genes are not even epistemically independent. Finally, I briefly draw some lessons from the arguments.

1 Two Reasons for the Apparent Independency of Genes

Why do genes have an apparent independency? Here, I briefly explain two of the reasons, one originating from the history of the concept itself and the other deriving from modern biotechnology. Today, the origin of the concept of the gene is considered to lie in the Mendelian factor from early genetics. In this context, a gene is considered as a particulate entity that is responsible for a certain phenotype and obeys the laws of segregation and independence. When it turned out that genes are located on chromosomes, they were likened to beads by Thomas Hunt Morgan. This traditional view of the gene seems to be still vividly alive even after the discovery of the double helical structure of DNA. Today, most of the philosophical issues on the gene concern its definition, with most scientists and philosophers focusing on demarcation—in other words, how to divide the genome into genes (e.g., Griffiths and Stotz 2007; Gerstein et al. 2007). Of course, an exact definition and a clear demarcation do have their practical uses in the progress of science. However, remnants of the age of Morgan—specifically the belief that a gene is a separable entity—have survived to this day and are one of the reasons behind their persistence in issues of demarcation.

Modern biotechnology reinforced this traditional view of the gene. Recombinant DNA technology is the most important among the diverse genetic engineering technologies. Inserting a foreign gene into the genome (or a plasmid) of a host cell has now become a technology routinely used in life sciences. For example, a gene encoding GFP (i.e., the green fluorescent protein of Aequorea victoria) is introduced into the neighboring downstream region of a target gene for determining the localization of the gene product. Because of the ease of tracking the fluorescent molecule (the fluorescence can be observed by the naked eye), this process has become one of the most basic techniques in biological research. Today, genes are routinely cut out of surrounding DNA regions and recombined with the host's DNA as separable entities, enforcing the belief that they are such entities.

2 The Ontological Status of the Gene

Contrary to the apparent independency of genes, however, it is difficult for life scientists to draw a clear line between a gene and the surrounding DNA...