That life is hierarchically organized, with species composed of populations, populations of individuals, individuals of cells, cells of organelles, organelles of genomes, genomes of chromosomes, and chromosomes of genes, is so obvious an observation that it is quite remarkable that we have no general explanation of why this is so. –Leo Buss, The Evolution of Individuality, p. 183
Image from Goodreads.
One of my pet topics is the concept of biological individuality, which I’ve written about quite a lot here. One question that comes up often, in fact what I initially asked Dr. Pepper when he used to carry on about it, is why does it matter?
So much ink has been spilled trying to define what an individual is, in the peer-reviewed literature of philosophy and of biology, as well as several books dedicated to the topic. What is the point of all this, to justify so much intellectual effort and so many dead trees?
In 1950, a young assistant professor at Princeton University published an essay about Volvox in Scientific American, “Volvox: a colony of cells.” The essay touches on several themes that will be familiar to regular readers of Fierce Roller, including cellular differentiation, inversion, and what it means to be an individual.
The author was John Tyler Bonner, whose (much) more recent work I’ve written about previously (“Chance favors the minute animalcule: John Tyler Bonner on randomness“).
John Tyler Bonner, ca. 1957. Image from the Guggenheim Foundation.
Among many other contributions, Bonner was a pioneer in the development of the social amoeba (or cellular slime mold) Dictyostelium discoideum as a model system for multicellular development and cell-cell signaling. A member of the National Academy of Sciences and a fellow of the American Association for the Advancement of Science, he has published over twenty books and mountains of peer-reviewed papers.
Process philosophy has really just recently come on my radar, and I’m not sure what to make of it. I have written before that I don’t have a particularly strong background in philosophy, and so I’m hesitant to judge what I may not understand. At least some of the descriptions I’ve seen strike me as quasi-mystical word salads:
In short, a becoming actual entity prehends, or “feels,” not only other, past actual entities (which may be seen as the metaphysical basis for causality wherein one entity becomes part of another entity’s formation process), but also eternal objects (i.e., “pure possibilities”), which introduces novelty into the process. –Lukasz Lamza in Nature Alive – Essays on the Emergence and Evolution of Living Agents
One reason to study green algae is because they can teach us something about the evolution of multicellularity. A number of related species in the Volvocalean family form a gradation of complexity between single-celled and simple multicellular organisms. The members of this family of algae differ in size, the number of cells they produce, and whether or not there is a split between germline and somatic cells. This split is thought to be central to understanding how a new level of individuality has evolved. — Calcott 2011, p. 39.
I have an interest with the philosophy of biology, but I’m a dilettante. My background is in evolutionary biology; I haven’t had a philosophy class since I was an undergrad at UCF. Nevertheless, if you study the so-called Major Transitions, you’re inevitably going to end up reading some philosophy. Topics such as multilevel selection, emergence, and the nature of biological individuality come up over and over again in this field, and philosophers of biology have made important contributions in all of them.
Among these, I find discussions of the nature of biological individuality fascinating, and I’ve written about it often here. Volvox and its relatives often come up in these discussions, and they have for a long time. A new edited volume, Nature Alive, continues this trend in a chapter by Lukasz Lamza (“Cells, organisms, colonies, communities–the fuzziness of individuality in modern biology”).
S. Lidgard & L. K. Nyhart, eds. 2017, Biological Individuality: Integrating Scientific, Philosophical, and Historical Perspectives. University of Chicago Press, Chicago.
Pierrick Bourrat has reviewed Scott Lidgard and Lynn Nyhart’s book Biological Individuality: Integrating Scientific, Philosophical, and Historical Perspectives for Notre Dame Philosophical Reviews.
By Ernst Haeckel – Kunstformen der Natur (1904), plate 17: Siphonophorae (see here, here and here), Public Domain, Link
Derek Skillings from University of Bordeaux/CNRS has a new article at Aeon about biological individuality:
For millennia, naturalists and philosophers have struggled to define the most fundamental units of living systems and to delimit the precise boundaries of the organisms that inhabit our planet. This difficulty is partly a product of the search for a singular theory that can be used to carve up all of the living world at its joints.
Skillings reviews the deep historical roots of the question, touching on the views of Charles Darwin and his grandfather, both Huxleys (T. H. and Julian), Herbert Spencer, and other 19th and early 20th century thinkers, as well as some more recent authors, including Daniel Janzen and Peter Godfrey Smith.
Dinah Davison and Erik Hanschen.
A couple of weeks ago, I indulged in a little shameless self-promotion, writing about my new chapter on volvocine individuality in Biological Individuality, Integrating Scientific, Philosophical, and Historical Perspectives. Now two graduate students in the Michod lab at the University of Arizona, Erik Hanschen and Dinah Davison, have published their own take on volvocine individuality in Philosophy, Theory, and Practice in Biology (“Evolution of individuality: a case study in the volvocine green algae“). The article is open-access, and Hanschen and Davison are listed as equal contributors.
As I mentioned previously, I have a chapter in the newly published book Biological Individuality, Integrating Scientific, Philosophical, and Historical Perspectives. The chapter was actually written nearly five years ago, but things move more slowly in the philosophy world than that of biology. Finally, though, both the print and electronic versions are now available; here is the electronic version of my chapter. The book currently has no reviews on Amazon, so if you want to give it a read, yours could be the first. If you’re interested in current and historical views on individuality, there is a lot of good stuff in here, including contributions by Scott Lidgard & Lynn Nyhart, Beckett Sterner, Andrew Reynolds, Snait Gissis, Olivier Rieppel, Michael Osborne, Hannah Landecker, Ingo Brigandt, James Elwick, Scott Gilbert, and Alan Love & Ingo Brigandt.