hpb etc.

Returning

I will return to the blogosphere next week. A recent topic of John Hawks', "Theory or law?" woke me up a little. I hope to add something constructive to the discussion. (Of course, by the time I get to it, Hawks will have already published 763 posts.)

Philosophy of Biology Cafe

My colleague Matt Haber (Philosophy, Utah) introduced me to his new venture, the Philosophy of Biology Cafe. According to the site:

This forum is a place to come, sit down, and have a hearty swig of the many topics concerning philosophy and biology. We try to keep things in a coffee-house theme (in case you didn't notice) so if you have any concerns, please contact one of our baristas (moderators).

It's nice to see some innovation in the blogosphere broadly construed. Matt has set up any number of forums, from research to biology & society to journals, to calls for papers. Everthing's there, nicely organized.

At the moment, the Philosophy of Biology Cafe is in alpha-testing, but I can see some momentum beginning to build, and beta-testing is around the corner. Stop by and take a look.

Fisher on the Brain

Greetings from the North of England. This post has nothing really to do with the photos, but that I've had these thoughts while walking along the River Wear and gazing at the Durham Castle from my office at the IAS.

In a post from the not-too-distant past, I sketched some views about whether Fisher's 'fundamental theorem' of natural selection is 'fundamental' (in some sense to be discovered and not defined). Here are those views again, presented in a slightly different way, with the addition of Alan Grafen's (2003) view. At the end, I state what I think is the best that can be said for the theorem's biological importance. (Thanks to all the folks in the Department of Science and Technology Studies at University College London who patiently listened to my seminar on the topic --and to Joe Cain who hosted me.)

Here's the theorem as we know it today (Edwards 1994, p. 450):

The rate of increase in the mean fitness of any population at any time ascribable to natural selection acting through changes in gene frequencies is exactly equal to its additive genetic variance at that time.

Here's a litany of folks who've evaluated the theorem's significance.

Fisher ([1930] 1999, pp. 36-37)

"[T]he fundamental theorem ... bears some remarkable resemblances to the second law of thermodynamics. Both are properties of populations, or aggregates, true irrespective of the nature of the units which compose them; both are statistical laws; each requires the constant increase in a measurable quantity, in the one case the entropy of the physical system and in the other the fitness ... of a biological population ... Professor Eddington has recently remarked that 'The law that entropy always increases --the second law of thermodynamics-- holds, I think, the supreme position among the laws of nature'. It is not a little instructive that so similar a law should hold the supreme position among the biological sciences."

Price (1972, pp. 139-140)

"First of all, the generality of [Fisher's] theorem is very great since it depends only on statistical smoothing through large population size and on assumptions of absence of meiotic and gametic selection that are involved in the derivation of [the theorem]."

"We may next note that the 'fundamental theorem' is very probably the most that anyone has yet been able to say correctly about evolutionary increase in fitness under general and realistic natural conditions. Thus, the theorem is by no means a trivial, uninteresting result."

"Still one feels disappointed that it does not say more ... Much more interesting would be a theorem telling of increase in 'fitness' defined in terms of some fixed standard. Thus there is the challenge here to find a deeper definition of this elusive concept 'fitness' and to give a deeper explanation of why it increases and under what conditions."

Ewens (1989, pp. 178-179)

"Price's concluding view [of the theorem] is in the negative, and he is 'disappointed that [the theorem] does not say more' ... These views are in line with my own negative assessment of the theorem as a biological statement."

"... [T]here appears to be no justification for singling out the partial change [in mean fitness] as isolating the 'natural selection' or 'change in gene frequency' component of the total change in mean fitness ...."

... "[W]e are left with the Fundamental Theorem as an exact, although possibly incomplete, evolutionary principle."

Edwards (1994, pp. 469-471)

"First is the historical fact ... that [the theorem] led Wright to the idea of an adaptive topography in gene-frequency space which has dominated so much thinking in evolutionary biology."

"Secondly, and of more permanent value, is the fact that the theorem gives mathematical precision to the previously vague notion 'that in species in which a higher proportion of the total variance is ascribable to genetic causes, the effective selection will be more intense than in species in which the variance is to a larger extent ascribable to environmental variations'."

"The third reason why the theorem is important is that correctly interpreted is has a considerable potential for future developments in mathematical population genetics."

Grafen (2003, p. 325)

"I have come to believe that Fisher was right in his beliefs about the importance of the theorem ... In my view, Fisher thought that his fundamental theorem isolated what we might call the adaptive engine of Darwinian natural selection."

"Thus the partial nature of change is not an inability to find a stronger result [contra Price and Ewens]. Fisher believed that this partial change was the only aspect of the changes in a population's genetic constitution that was progressive, that could create design."

Plutynski (2006, p. 75)

"Why did Fisher regard his theorem as so very 'fundamental'? The answer is that the fundamental theorem was a culmination of Fisher's lifelong project to vindicate Darwinism and unify the biometrical gradualist model of evolution and Mendelism in a rigorous mathematical theorem analogous to the physical sciences."

Here's about the best I think can be said about the theorem, based on what's gone before:

Fisher, Price, and Ewens are right that the scope of the theorem is very broad, but Price and Ewens are wrong to imply that scope is irrelevant to the theorem's biological significance. If there's anything to the claim that science (whatever "science" is) aims for general law-like statements or universal laws, then scope is relevant to the theorem's being fundamental. Price and Ewens are also wrong that the theorem's "incompleteness" is a defect because....

Fisher, Edwards, and Grafen are right that Fisher's isolation of natural selection and the additive genetic variance is a biologically deep statement that sets the speed limit on adaptive evolution. That is, the partial change in mean fitness says something biologically deep about the nature of selection. And, anyway, Edwards points out that the theorem is expandable (rather than worrying about its being incomplete). Of course, Edwards and Grafen are wrong to not include scope.

(Note that I've left out Plutynski. I think she's answering the wrong question.)

I'm not sure how far I can go to endorse the above. My main concern is that "additive genetic variance" is not biologically special. That is, I think Ewens is on to something when he says that there's no justification for isolating any change in gene frequencies that calls out natural selection. But, in order to really make my concern into a criticism, I've got to work through a bunch of literature on the relationship between additive and non-additive genetic variance and natural selection. Of course, I don't think doing so will settle anything. Folks get very ... excited about additive genetic variance, narrow heritability, the breeder's equation and all that. And I'm not sure I have anything original to say. But we'll see.

References

A. W. F. Edwards (1994), "The Fundamental Theorem of Natural Selection", Biol. Rev. 69: 443-474.

W. Ewens (1989), "An Interpretation and Proof of the Fundamental Theorem of Natural Selection", Theo. Pop. Bio. 36: 167-180.

R. A. Fisher ([1930] 1999), The Genetical Theory of Natural Selection. Oxford University Press.

A. Grafen (2003), ""Fisher the Evolutionary Biologist", The Statistician 52: 319-329.

G. Price (1972), "Fisher's 'Fundamental Theorem' Made Clear", Ann. Hum. Genet., Lond. 36: 129-140.

A. Plutynski (2006), "What Was Fisher's Fundamental Theorem of Natural Selection and What Was It For?", Stud. Hist. Phil. Biol. & Biomed. Sci. 37: 59-82.

Off to Durham --England, not North Carolina

On Wednesday (18 April), all of us (me, my wife, my daughter) head off to Durham, England for my Fellowship period (through June) at the Institute of Advanced Study (housed in Cosins Hall pictured above) at Durham University. I'll be hosted at Van Mildert College.

There, I intend to get back to blogging (hard to believe?), mostly on the work I'll be doing, on Fisher, but also on what's going on at the Institute. There'll be a bit of a travelogue as well, assuming I remember to take the digital camera out of my suitcase.

Upcoming Events

There are two small, philosophy of biology conferences coming up, both of which are accepting submissions. The first is hosted by the Center for Philosophy of Biology at Duke University:

"Chance in Evolution"
April 6-8, 2007

Invited speakers include:
Richard Lewontin (Harvard)
Roberta Millstein (UC Davis)
John Beatty (University of British Columbia) and
Robert Brandon (Duke)

The conference is being organized by the Center's post doc, Chris Haufe, and he is accepting submissions until 1 March. Go here to see what's what.

The second conference follows on the heels of Duke's, and is the 22nd Regional Conference on the History and Philosophy of Science on microbial evolution at the University of Colorado, Boulder:

"Moving Beyond Darwin: The New Evolution"
April 13-15, 2007

Invited speakers include:
John Dupré (University of Exeter)
Jan Sapp (York University) and
Norm Pace (University of Colorado)

Abtract and paper submissions are being accepted through 6 March by Carol Cleland in the Department of Philosophy at Colorado. Go here to see what's what.

Looks like I'll submit to the Duke conference given that I've been thinking a lot about chance in evolution recently.

Biohumanities at Queensland

I draw your attention to the Biohumanities Project at the University of Queensland, Australia. Paul Griffiths, an ARC Federation Fellow, is director of the project. As the site explains,

Biohumanities studies 'biology' in two senses: the scientific discipline of biology and the objects it studies: biomolecules, animals, ecosystems and so forth. The history of biology encompasses not only scientific institutions, apparatus and laboratory practice, but also the objects of biological inquiry. The laboratory fruit fly or a cell-line preserved in laboratories around the world each have their own histories. Similarly, philosophers of biology conduct conceptual investigations of the nature of biological taxa (species, genera, families, etc) as well as studying the distinctive features of disciplines like biological taxonomy whose products are classifications rather than more stereotypical forms of scientific discovery.

I encourage readers to explore the site. But, in particular, I encourage readers to subscribe the Project's podcasts, which includes the proceedings of:

4th Queensland Biohumanities Conference: Evidence-based Medicine. January, 2007. Keynote Speaker: Jerry Ravetz.

3rd Queensland Biohumanities Conference: Idealisation, Mechanism and Reduction: New Directions in the Philosophy of Proximal Biology. December, 2006. Keynote speakers: William Bechtel, Marcel Weber, Alexander Rosenberg.

2nd Queensland Biohumanities Conference: Philosophy of Ecology. June, 2006. Speakers include Mark Colyvan, Jay Odenbaugh, Kim Sterelny, Hugh Possingham, Greg Mikkelsen.

1st Queensland Biohumanities Conference: The Conceptual Impact of the Genomic Revolution. October 2005.  Keynote addresses: Paul Griffiths & Karola Stotz, John Dupré & Maureen O'Malley, Kenneth Schaffner.

Other speakers featured on the site include Samir Okasha, Jonathan Kaplan and Robert Solomon. All worthwhile stuff!