Courtesy of reader Jocelyn Stoller, comes this video, of respected philosopher of science Jim Woodward discussing whether or not religious beliefs explains things like suicide bombing and the moral right in the US.
Answer: not likely. Watch part 2 at Youtube.
Filed under Philosophy, Religion, Science
Populations arise imperceptibly; it is only when they have reached a certain degree of development that we begin to think of their existence. This increase is more or less rapid, and it proceeds either from an excess of births over deaths, or from immigrations, or both. In general, it is a mark of wellbeing, and of the means of existence being superior to the wants of the actual population. If we approach or exceed this limit, the state of increase soon stops, or a contrary condition may take place. It is then interesting to examine how different countries are populated, what are the means of subsistence and the rate of increase of the people, and to assign the limit which they may reach without danger. After that, the consideration is, to know the composition of the population, and if the constituent elements are advantageously distributed, and contribute, in a more or less efficient manner, to the well-being of the whole. But it would be proper first to take the questions or highest moment, and to establish, in a summary and clear manner, the ideas on population promulgated by the most distinguished economists. It appears incontestible, that population would increase in a geometrical ratio, if no obstacle were presented to its development. The means of subsistence are not developed so rapidly; and, according to Malthus, in the most favourable circumstances for industry, they can never increase quicker than in an arithmetical ratio.
The obstacle to population, then, is the want of food, proceeding from the difference of ratio which these two quantities follow in their respective increases. When a population, in its development, has arrived at the level of its means of subsistence, it ought to stop at this limit, from human foresight; or if it have the misfortune to overleap this limit, it must be forcibly brought back by an excess of mortality. The obstacles to population, therefore, may be arranged under two heads—the one acts by preventing the growth of population, and the other by destroying it in proportion as it is formed. The sum of the first forms what may be called the privative obstacle, that of the second the destructive obstacle.
Mr Malthus has analysed, with great sagacity, the principal obstacles to its increase which population has met with; he has determined. with no less credit, the limit which it cannot pass without being exposed to the greatest danger. However, it may be necessary to remark, notwithstanding the researches of the English philosopher, and of the economists who have followed in his track, that the modus operandi of the obstacles has not been clearly made out. The law has not been established by virtue of which they operate: in a word, they have not afforded the means of carrying the theory of population into the domains of mathematical science, to which it seems particularly to belong. Hence it results, that the discussion of this delicate point has not been completed at the present day, and the dangers attending society have perhaps been exaggerated, from not finding sufficient security in the action of the obstacles against an evil, the dreadful rapidity of which followed a geometrical progression.
To endeavour to fill up so important a lacuna, I have made numerous researches, the details of which it will be superfluous here to present; and an attentive examination of the state of the question has proved to me, that the theory of population may be reduced to the two following principles, which I consider will hereafter serve as fundamental principles in the analysis of the development of population, and of the causes which influence it.
Population tends to increase in a geometrical ratio.
The resistance, or sum of the obstacles to its development, is, all things being equal, as the square of the rapidity with which it tends to increase.
M Adolphe Quetelet, A treatise on man and the development of his faculties, Edinburgh, William and Robert Chambers, 1842 [1835], page 48f.
The late Ernst Mayr is remembered for many things, but a number of his historical and philosophical claims are unravelling. The very clever and perspicacious Rutgers geneticist, Jody Hey, has published a paper in the Quarterly Review of Biology on one of these. Jody is a very good reader of history as well as being a leading geneticist, and he made an observation to me that I followed up in my book, that the “species problem” is a post-Mendelian invention, and that what the pre-Mendelians had was a “species question” – what was the origin of novel species?
Here is the abstract of his paper:
Ernst Mayr said that one of Darwin’s greatest contributions was to show scholars the way to population thinking, and to help them discard a mindset of typological thinking. Population thinking rejects a focus on a central representative type, and emphasizes the variation among individuals. However, Mayr’s choice of terms has led to confusion, particularly among biologists who study natural populations. Both population thinking and the concept of a biological population were inspired by Darwin, and from Darwin the chain for both concepts runs through Francis Galton who introduced the statistical usage of “population” that appears in Mayr’s population thinking. It was Galton’s “population” that was modified by geneticists and biometricians in the early 20th century to refer to an interbreeding and evolving community of organisms. Under this meaning, a population is a biological entity and so paradoxically population thinking, which emphasizes variation at the expense of dwelling on entities, is usually not about populations. Mayr did not address the potential for misunderstanding, but for him the important part of the population concept was that the organisms within a population were variable, and so he probably thought there should not be confusion between population thinking and the concept of a population.
I think Jody is being too nice. Statistical thinking originated with Adolphe Quetelet, the Belgian astronomer, in the 1830s, and his ideas are very far from the notion of variability relied upon (and also not original to) Darwin. If anything, the notion of a statistical population is indirectly the result of Darwin, via Galton, which is what Jody argues in this paper.
All I can add is my explanation of why this and so many other claims arose unjustifiably about Darwin’s originality in all fields. Every fifty years since Darwin’s death, on the anniversary of the Origin in 1908/9, 1958/9 and 2008/9, there are, understandably, celebrations and conferences held. These tend to ramp up in the preceding years. Now, few scientists are as well studied or understood as Darwin – even Newton is not as well studied – so it is hard to find more to say. One trick is to make Darwin seem to have covered every base, philosophical as well as scientific. So he gets all kinds of ideas ascribed to him that he did not overtly, and often likely not even covertly, held. As I argued in my paper “Not Saint Darwin” during the last round, Darwin is good enough for what he did achieve. Let’s not make him out to be the sole source of scientific progress in biology as well.
Jody Hey (2011). Regarding the confusion between the population concept and Mayr’s “population thinking” Quarterly Review of Biology, 86 (4), 253-264
Filed under Biology, Evolution, History, Metaphysics, Philosophy, Science, Species concept
Notes on Novelty series:
1. Introduction
2. Historical considerations – before and after evolution
3: The meaning of evolutionary novelty
4: Examples – the beetle’s horns and the turtle’s shell
5: Evolutionary radiations and individuation
6: Levels of description
7: Surprise!
8: Conclusion – Post evo-devo
And having come to know that it is, we inquire what it is [Aristotle, Posterior Analytics, II.1.89b34–35, translated in Lennox 2006: 296]
Consider this diagram:
Stag beetle images from FCIT, royalty free.
Every description of the phenotype of the beetle has some grain of resolution, which is to say that some things are described while others are not. this may be because some grain of resolution is ignored due to it being irrelevant to the purpose of the description, or it may be because that grain is not yet known or understood. Traditionally, organisms are treated as what Sober once called the “benchmark entity” (Sober 1984: 280, 317), the standard grain of resolution. Sometimes, however, that grain is either too gross or too fine for the purposes of describing what is occurring. The notion of a “superorganism” (Hölldobler and Wilson 2009) is a case in point: the appropriate grain of description given what we know of insect colonies is the colony, not the organism.
However, sometimes (as is the case with Wilson and his colleagues), the need to describe at a certain grain is taken to imply some absolute “level” or “rank”; that is, to imply an ontological and metaphysical scale. This is a case of “Descartes before the horse”, taking semantic and conceptual properties to imply real world properties of the things being described. It is a common philosopher’s error, but equally a common biologist’s error, and in particular a common error of evolutionary systematists.
Let us generalise this a bit. Description of biological systems and facts is like this:
What counts as “observed phenomena” depends crucially on the instruments and assays used to observe. The naked eye when untrained has certain dispositions to observe, for example, organisms, but a trained eye can see traits, characters or even entire ecological objects; and having a grain of description at one level means the observer can decompose the observed phenomena into parts, or compose the parts (including organisms) into larger encompassing wholes, depending upon the needs of the describer.
If an explanation at a descriptor grain serves our purposes, then we can rest there. So, for example, if a representation of the spread of a gross trait can be cast in terms of organisms and their interactions with the rest of the world, then we do not need to go deeper (unless our purposes are reductive). Taking an organism grain resolution effectively makes the lifecycle of the organism type our focus, and so we have to decompose organisms into developmental parts and stages. But if we cannot explain what the causes of the parts are at that grain of resolution, we will then decompose the descriptions and accounts to finer grain descriptors (such as genes).
The mistake is to think there is a privileged grain or mode of description. If we understand that description is context, interest, and purpose relative, then a failure to explain something like an evolutionary sequence at one level of description is merely an invitation to change the grain, by composition or decomposition, until we find something promising as an avenue of explanation. In the next post I will discuss what make a grain satisfactory, and ask again: did Darwin give us the explanations of novelty?
Filed under Epistemology, Evolution, Metaphysics, Philosophy, Science
I don’t much like Facebook, especially their privacy failures, but I know it is an important venue for many to follow the blog, so I set up an Evolving Thoughts Facebook Page, and with luck this link will take you to it. Let me know if it doesn’t.
Also if it works, this and all subsequent posts will be reposted there due to some plug-in magic.
Filed under Administrative
Here’s a conundrum for the simple minded:
One of the classic fallacies is the fallacy of affirming the consequent:
If P then Q, Q, therefore P
It’s an obvious logical fallacy because there might be many reasons for Q. And yet, all science rests on doing just that. Suppose I wish to test whether Quargles are caused by Pruntles. I set up the conditions for Quargles to be produced by Pruntles, and find that Quargles result. I have therefore tested the hypothesis If Pruntles then Quargles. No, says the logician (i.e., Popper), you haven’t.
But remove affirming the consequent from science, and science would grind to a full stop. Science done Popper’s way would end science altogether (and this is shown by the fact that those scientists who claim to be Popperians have to do all kinds of acrobatics to show that testing hypotheses is actually a kind of falsification of non-hypotheses). Experimental replication is still affirmation of the consequent.
Now historical hypotheses are of the form:
If P then Q
[Event E is a kind of P; Outcome O is a kind of Q]
E occurred
O resulted
E caused O (If P then Q is true)
The test is that the rule If P then Q is consistent with E and O for many E’s and many O’s. But each one is a case of affirming the consequent. Therefore all history is unscientific (I have read people saying exactly this). But I say we do know about the past, and we do it by affirming the consequent, just as we use affirmation of the consequent for most science.
What’s up with that?
Filed under Epistemology, Philosophy, Science
So in lieu of doing something useful, here is a list of links to my substantial posts of 2011:
Holy logorrhoea, Batman! Enjoy. Maybe I should publish Evolving Thoughts as a book.
Filed under Administrative
Notes on Novelty series:
1. Introduction
2. Historical considerations – before and after evolution
3: The meaning of evolutionary novelty
4: Examples – the beetle’s horns and the turtle’s shell
5: Evolutionary radiations and individuation
6: Levels of description
7: Surprise!
8: Conclusion – Post evo-devo
Sometime around 1900, Henry Fairfield Osborn (the Ernst Mayr of his day), appropriated the term “adaptive radiation” from botanical writers a few years earlier and published “The Law of Adaptive Radiation”, in which he argued that we could not only identify these radiative events, but the centres of their origin. The notion of an “evolutionary radiation” developed soon after, and by the time of the modern synthesis, the notion of adaptive radiations, adaptive zones, and adaptive niches had become firmly established in the lexicon of evolution. Classifications in terms of these ideas also became popular, leading to the eventual and inevitable (and somewhat absurd) suggestion by Julian Huxley in 1957 that since humans alone occupied the “adaptive zone” of intelligence, they should be classified in an entirely distinct major grade on a par with Metazoa, Psychozoa. Huxley explicitly discussed these in terms of grades.
This gradism is rife among those who adopt evolutionary stances; indeed it has almost become doctrine. And, despite the objections of some cladists, there is nothing wrong with developing and testing hypotheses of grade novelties; the problem arises when clades and grades are forced into hybrid classifications. On the Arthurian definition of novelty, every differentiae that give a clade, no matter how subjectively big or small, is an evolutionary novelty. Novelty is effectively just speciation (or even lower, if haplotype groups and other coalescent trees are acceptable). The evolutionary (in the sense of the modern synthetic account) definition, however, mixes the qualitative criteria of “grade” with the quantitative criteria of apomorphies. The inferential warrant of these hybrid classifications is highly limited.
Effectively, grades are statements that have two places for every predicate: the properties observed, and the criteria salient to the observer. A grade statement is a statement about the observers as well as the organisms. A clade statement, however, is held not to be. It takes the properties that are measurable by any observer, in theory at any rate, and processes the differences more or less algorithmically. It doesn’t matter if the characters being measured were, before the observation, specified as being “significant” or “important” or “novel”; so long as they can reasonably be held to be homologies between the groups. A novelty in this case is a trait (a character state, or roughly the value assigned to the character) that has no homologs in the compared groups.
So individuating the characters/traits is critical to classifying novelties. As the beetle case shows, what looks like it was novel (without homology) at the level of description of the gross phenotype (carapace and mating behaviour), turns out to be a co-option of prior genetic and developmental mechanisms. The homology is at a deeper level of description. Individuation of traits is a fraught topic in biology. Gould and Lewontin accused reductionist evolutionists of “inappropriate atomization” of traits (1979: 585), declaring that organisms are “integrated entities, not collections of discrete objects”. Often the individuation of parts depends on what the assay techniques are: visual inspection, fossilisation, molecular assays, cytological staining, and so forth. Atomisation appears to occur based on what techniques for gathering differentiae are used. Even the notion of individual organisms has been challenged, in part by “extended phenotype” views and in part by endosymbiosis and gastrointestinal florae. As George Williams (1992: 9) once noted, holists and reductionists are largely separated by the size of the glassware they use – test tubes and petri dishes (I would add slides and pipettes) for reductionists, and terraria, aquaria, and specimen bottles for holists.
To call somebody a reductionist is often thought to be an insult or a dismissal of a simplistic and atomistic philosophy that Everybody Knows has failed. Explanation is supposed to be targeted to the Whole, the organism, or the ecosystem, or even systems in general. And yet, studies like the ones Shubin et al. cite show that the successful approach of reduction (looking for underlying mechanisms) in explanation is not only not dead, but solving problems that have bothered us for some time. However, this doesn’t mean one can leap to the conclusion that reductive explanations will always work, or even that we must be reductive when we can. If an explanation works at a particular level of description, there is no need to reduce it further. I might be able to explain the traffic patterns of Sydney through the use of very general considerations in which the properties of the individual cars are irrelevant to the explanandum of flow rates and snarls. It adds nothing to the understanding to point out that 22% of all sedans are red, or that European cars account for 15% of all traffic, if the relevant properties are indiscernibly different (neither red cars nor European cars go appreciably faster in urban traffic).
So if we can give an explanation at a level of description that satisfies our epistemic and explanatory needs, the homologies of that level of description are enough. However, there will inevitably be other epistemic and explanatory needs not met by a gross description. For example, if I can state with any evidence and authority that of two traits in a given population of organisms in an ecotype, one is fitter and will move to fixation, I have explained the dominance of that trait and made a prediction. However, at that level I am none the wiser about the physiology, development and genetics of that trait. Since these are different explanatory projects to the question of populational distributions, that doesn’t matter in one sense. But it matters to the physiologists, developmental biologists (who really need a better name; might I suggest ontogenists?) and molecular biologists, and so they give their finer grain descriptions in setting up their own research projects.
The question of novelty crosses these grains of description. Take a novel structure like the turtle’s shell. It is novel because we describe the gross morphology of shell, plastron etc in terms we do not apply to near relatives. It is novel because at the level of description of gross adult anatomy, we have an inversion of topological configurations found in relatives. That sets up the problem; the solution is found by appealing to finer grain accounts of development, etc. This leads us to conclude that finer grain accounts should be appealed to in all cases, if we were to be complete about our biology; but everybody knows there is only so many research hours and dollars, and so we leave the details to one side except when there is a problem like this.
So next we need to consider what a level of description is, and how it is chosen.
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Filed under Epistemology, Evolution, Metaphysics, Philosophy, Science, Species and systematics
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