A Philosopher Chastises Reductionist Myopia
"Through their thorough arguments, the essays in Processes of Life challenge widely held assumptions about biology and evolution. Dupr� provides a view of life grounded in recent research and current understanding. His perspective also reminds us how much we do not know."
This is how Christian Julian Villabona-Arenas ends his review in Science of John Dupr�'s new collection of essays, Processes of Life: Essays in the Philosophy of Biology (Oxford University Press, 2012). We've mentioned Dupr� before here, here and here. He's a philosopher of biology who describes himself as a philosophical naturalist, but is critical of reductionism. Based on Villabona-Arenas's review, the book offers more criticisms of Darwinism than supports for it.
As philosophers are wont to be, Dupr� is a gadfly raising doubts about all the things scientists take for granted: What is life? What is a species? What is an organism? What is a gene?
One fundamental argument Dupr� offers against reductionism is that biology works with concepts that depend not only on their constituents but also on the larger systems of which they are part. Debates over the nature of species have generated a substantial fraction of the evolutionary biology literature; less attention has been placed on the definition of genes. In addition to the concerns around such issues, there is the central question of what constitutes the individual organism. (Emphasis added.)Inherent in these questions are questions about evolution. At several points in his review, Villabona-Arenas, a molecular evolutionist at the University of S�o Paulo, indicates that Dupr� is critical of standard evolutionary theory to the point of chastising evolutionists for their pretensions. But at no point in the review does the reviewer show the author granting neo-Darwinism evidentiary support, even though he is clearly an evolutionist himself.
For instance, the title of his review, "Ending Microbial Myopia," alludes to Dupr�'s contention that microbes are far more significant than "macrobes" (anything not a microbe) as units of evolution. For most of earth history, they were it:
Although their scientific importance remains generally unappreciated, microbes surpass macrobes (a term Dupr� advocates for those organisms that are not bacteria, archaea, or protists) in their contribution to evolutionary history: the first three billion years of life on Earth were overwhelmingly microbial. Even today, they include most living things, exhibit a greater metabolic diversity, and inhabit a wider range of environments (including extremely harsh ones); their collaborative enterprise is so extensive that at the heart of every interface between multicellular eukaryotes and the external environment lies a complex multispecies microbial community. In three essays, Dupr� and coauthor Maureen A. O'Malley (University of Sydney) present a strong case for ending the myopia that leads us to undervalue microbes.That being said, does Dupr� show how they came to be? On the contrary, in describing the complexity and variety of microbes, and their interactions, he leaves the door wide open for reassessment of basic evolutionary concepts:
As Dupr� and O'Malley note, paying proper attention to microbes has already yielded observations that may force us to rethink fundamental ideas about evolution. In light of the extent of lateral gene transfer, the "tree of life" seems better considered as a net. Studies of cooperation, development, competition, and communication among unicellular organisms have revealed that they can possess many of the characteristics used to define multicellularity. Given that the entities that form lineages are not always the same as those that form metabolic wholes, collaboration may be the central characteristic of living matter. Traditional organisms cannot be seen as "'the' biological individuals on which selection operates." Abandoning some theoretical commitments will open the way for further understanding nature.Looking at a few finch beaks, in other words, puts the focus on irrelevant details but misses the big picture. It's myopic, Dupr� is saying, to see an individual bird or moth as a unit of selection when the living world is a complex, interacting, cooperative, dynamic whole. We might even treat our own microbial travelers (that comprise 90% of the cells we carry with us) as one big "single composite entity." Dupr�'s view of the biosphere recalls a kind of Heraclitan flux that defies simplistic evolutionary principles. Villabona-Arenas writes,
A living world where none of the entities that constitute an organism are static implies an interactive flux subtly different in every iteration but similar enough to be a distinctive process. Because biological concepts are static abstractions from life processes and different abstractions provide different perspectives on these processes, we face considerable difficulties in reconciling satisfactory general concepts.So far, they've taken away Darwin's tree and replaced it with a net. They've questioned the unit of selection. They've elevated microbes to collaborative, communicating entities on par with multicellular organisms. They've undermined the ability to describe satisfactory general concepts of evolution. Will they provide something to rescue Darwin from obsolescence? No. They turn on the heat with epigenetics, undermining the Central Dogma:
The author's reasons for recognizing the importance of the environment accentuate the relevance of epigenetics and developmental systems theory, areas that for a long time attracted little interest but have now become very active. Beyond doubt, Dupr� emphasizes, the perpetuation of life from one generation to the next requires much more than simply the passage of DNA. He concludes that genomes do not merely store information. Because of their constant dynamic interaction with other constituents of the cell, their capacities depend not only on their sequence of base pairs. More important, those capacities are determined by the systems of which the DNA molecules are only part.That's not all. Dupr� continues by chastising evolutionary psychology, claiming that "evolution has had ample time since the Stone Age to shift our behavior" and "the complexity of the developmental interactions between a wide variety of internal and external factors" (such as epigenetics) discounts the evo-psych claim that we are as we are because we were as we were: e.g., we are obese because our hunter-gatherer ancestors had to store fat for periods of famine. "He applies similar reasoning in rejecting claims of genes for race, highlighting the mistake made in thinking of strings of DNA as having specific functions defined only in terms of phenotypic outcomes. For such reasons, he rejects genetic determinism."
Readers are undoubtedly finding implicit support in all these statements for intelligent design theory, while neo-Darwinism is getting a whipping. Don't look for a last-minute rescue. In his last paragraph, Villabona-Arenas ends the review with one last rebuke:
Through their thorough arguments, the essays in Processes of Life challenge widely held assumptions about biology and evolution. Dupr� provides a view of life grounded in recent research and current understanding. His perspective also reminds us how much we do not know.