The Gene Is Dead — Long Live the Gene! Conceptualizing Genes the Constructionist Way. In: Koslowski P, editor. Sociobiology and Bioeconomics. Berlin: Springer Berlin Heidelberg; 1999. pp. 105-37. [DOI: 10.1007/978-3-662-03825-3_6]

The Evolving Definition of the Term "Gene"

This paper presents a history of the changing meanings of the term "gene," over more than a century, and a discussion of why this word, so crucial to genetics, needs redefinition today. In this account, the first two phases of 20th century genetics are designated the "classical" and the "neoclassical" periods, and the current molecular-genetic era the "modern period." While the first two stages generated increasing clarity about the nature of the gene, the present period features complexity and confusion. Initially, the term "gene" was coined to denote an abstract "unit of inheritance," to which no specific material attributes were assigned. As the classical and neoclassical periods unfolded, the term became more concrete, first as a dimensionless point on a chromosome, then as a linear segment within a chromosome, and finally as a linear segment in the DNA molecule that encodes a polypeptide chain. This last definition, from the early 1960s, remains the one employed today, but developments since the 1970s have undermined its generality. Indeed, they raise questions about both the utility of the concept of a basic "unit of inheritance" and the long implicit belief that genes are autonomous agents. Here, we review findings that have made the classic molecular definition obsolete and propose a new one based on contemporary knowledge.

A novel hierarchical clustering algorithm for gene sequences

BACKGROUND

Clustering DNA sequences into functional groups is an important problem in bioinformatics. We propose a new alignment-free algorithm, mBKM, based on a new distance measure, DMk, for clustering gene sequences. This method transforms DNA sequences into the feature vectors which contain the occurrence, location and order relation of k-tuples in DNA sequence. Afterwards, a hierarchical procedure is applied to clustering DNA sequences based on the feature vectors.

RESULTS

The proposed distance measure and clustering method are evaluated by clustering functionally related genes and by phylogenetic analysis. This method is also compared with BlastClust, CD-HIT-EST and some others. The experimental results show our method is effective in classifying DNA sequences with similar biological characteristics and in discovering the underlying relationship among the sequences.

CONCLUSIONS

We introduced a novel clustering algorithm which is based on a new sequence similarity measure. It is effective in classifying DNA sequences with similar biological characteristics and in discovering the relationship among the sequences.

Tracking the shift to 'postgenomics'

Current knowledge about the variety and complexity of the processes that allow regulated gene expression in living organisms calls for a new understanding of genes. A 'postgenomic' understanding of genes as entities constituted during genome expression is outlined and illustrated with specific examples that formed part of a survey research instrument developed by two of the authors for an ongoing empirical study of conceptual change in contemporary biology.

Bridging the gap between developmental systems theory and evolutionary developmental biology

Many scientists and philosophers of science are troubled by the relative isolation of developmental from evolutionary biology. Reconciling the science of development with the science of heredity preoccupied a minority of biologists for much of the twentieth century, but these efforts were not corporately successful. Mainly in the past fifteen years, however, these previously dispersed integrating programmes have been themselves synthesized and so reinvigorated. Two of these more recent synthesizing endeavours are evolutionary developmental biology (EDB, or "evo-devo") and developmental systems theory (DST). While the former is a bourgeoning and scientifically well-respected biological discipline, the same cannot be said of DST, which is virtually unknown among biologists. In this review, we provide overviews of DST and EDB, summarize their key tenets, examine how they relate to one another and to the study of epigenetics, and survey the impact that DST and EDB have had (and in future should have) on biological theory and practice.

Interpreting the homeobox: metaphors of gene action and activation in development and evolution

Despite countless research efforts to demonstrate the precise developmental and evolutionary nature of homeobox genes, we are far from consensus on the role of this class of genes in development and evolution. This essay attempts to clarify the debate and to nip some problematic interpretations in the bud, by exploring metaphors of homeobox gene function in development and evolution.

The gene is not dead, merely orphaned and seeking a home

Despite announcements and obituaries, news of the death of the gene has been greatly exaggerated, or so says the gene as it struggles to survive and find a safe haven from which to steer its course through development and evolution. In this short piece, I consider recent claims that the gene is dead. I conclude that the gene is alive and well, living and functioning in the cell, which is both its natural home and a fundamental unit of evo-devo.