Philosophical presuppositions of evolutionary biology FFDI Zagreb 20

Philosophical presuppositions of evolutionary biology FFDI Zagreb, 20 -25 April 2015 • Prof. Dr. Winfried Löffler • • University of Innsbruck Department of Christian Philosophy Karl-Rahner-Platz 1 A-6020 Innsbruck, Austria • • winfried. loeffler@uibk. ac. at www. uibk. ac. at/philtheol/loeffler 1. Aims & method of this lecture 2. The received view: Aristotle’s biology 3. Evolutionary ideas until Darwin 4. History of evolutionary thought from Darwin to the present 5. Evolution: Theory-structures and concepts 6. Evolution between science and world-view 7. Summary & discussion

1. Aims and method of this lecture Aims: Some basics about current evolutionary biology Some basics about its historical backgrounds Understand its peculiar theoretical status Distinguish between scientific theory and its ideological interpretations / reductionisms Misunderstandings of anti-evolutionism Method: historical (2 -4, partly 6) to understand conceptual backgrounds

2. The received view: Aristotle’s biology 2. 1 Life and Works Aristotle (384 -322) today usually seen as philosopher, but first big encyclopedist Almost all scientific disciplines: - Physics, biology, physiology, meteorology, psychology, - economics, politology, aesthetics / poetology - ethics, rhetorics, philosophy of language, - philosophy of science - general philosophy (“first philosophy”, metaphysics)

Influential merits in the philosophy of science: - Important basic concepts (substance/accident, potential/actual, matter/form, efficient cause/final cause) - Classification of the scientific disciplines (theoretical/practical/poietical); (episteme / historia / techne) - Structure of scientific arguments (Prior Analytics, syllogism) - Structure of scientific classifications - Structure of an empirical science (empirical “first sentences” & logical derivations from them) – overcoming Platonism Heavy influence on Western thought!!!

2. 2 Biological writings - Historia animalium (History of Animals) - see later De partibus animalium (Parts of Animals) De generatione animalium (Generation of Animals) - Smaller writings (On movement of animals, sleep and sleeplessness, breathing, life and death etc. ) - Biggest part of his work is natural science! - Interestingly: little interest in medicine (son of a healer!) and botany

2. 3 Aristotle’s method in biology Empirical (broad sense) with speculative assumptions Classification of phenomena plus question for causes (“ 4 causes”) Reports of “experts”, own observations Maybe: “experiments”, anatomical sections (stages of fertilized eggs) Only scarcely: quantification (lengths); not weights, food intake etc. Only scarcely: ecological view (what it eats) Aim: Collection/classification of facts (historía) and research for causes

2. 3 Aristotle’s method in biology Teleology without design: Natural things seen as functional units with functional parts Teleological world-picture: Chief pattern of explanation: final explanation, what is it good for? Example: why do animals with a lung also have a neck? De part. An. III, 3 (Roughly): Bipartite lungs need some tube to partition the air; that tube needs a certain length, hence the windpipe. Hence also, the oesophagus/jednjak. Hence, the necessity of a neck. (Fish don’t need one). The vicinity of windpipe and oesophagus is technically bad and would cause trouble; hence, nature contrived the epiglottis. Nature as a whole is rational. Natura nihil facit frustra. Form follows function BUT: No external “design plans”.

2. 4 Aristotle’s taxonomy • 550 species according to morphological criteria, 300 re-identifiable today • Groups and similarity observations: e. g. , “all live-bearing quadrupeds have lungs and windpipes” • Attempts to a classification of the whole range of animals, morphological features; not always consistent and sometimes wrong • Man is included as a sub-class!

2. 4 Aristotle’s taxonomy An example from HA IV 1, 524 a 3 -20: “The octopus uses its tentacles both as feet and as hands; it draws in its food with the two that are placed over its mouth. The last of them, which is very sharp and is the only one which is whitish in colour and bifurcated at the tip —it is made so as to uncoil on the rhachis side (the rhachis being the smooth surface of the tentacle away from the suckers)—this one it uses in the act of copulation. In front of the sac and above the tentacles they have a hollow tube, by means of which they discharge from the sac any sea-water which may have come in while taking food into the mouth. The animal can move this tube to right and to left; it also discharges its “ink” through it. It swims obliquely in the direction of the so-called head, stretching out its feet; and by swimming in this way it can see forwards (since its eyes are on top), while its mouth is at the rear. So long as the animal is alive, the head is hard and as it were inflated. It takes hold of things and retains them with the underside of its tentacles, and the membrane between its feet is kept extended in its entirety. If it gets on to the sand, it can no longer retain its hold. […]”

Aristotle’s taxonomy (roughly): Animals with blood: (today: vertebrates) Live-bearing quadrupeds Egg-laying Quadrupeds Birds Fish Cetacea (sea mammals) Egg-laying footless (snakes) Live-bearing footless (vipers) Man Animals without blood: Cephalopods Molluscs Insects Crustaceans

2. 5 The stability of species Fundamental for 2300 years. Minimal traces of evolutionary ideas? (1) “Libya always produces something new” (De gen. an. II, 7): crossing of animal species at waterholes; reflection about the infertility of hybrids (2) Reflection about Empedocles’ (5. century BC) mythical explanation of the origin of life: plants first, then parts of animals, then animals, only the useful ones survived Aristotle: random combinations would not have survived (Phys. II, 8) (3) Knowledge about variation: not all animals conform to species, monstrosities, freak animals etc. (Not worrifying, just “freaks of nature”)

2. 6 Astonishing pioneerhoods and errors Pioneerhoods: Sexual life of octopus Opposition to preformation theory / homunculus theory of the sperm (until 19 th century!). “Epigenetic”, step by step, formation of organs – the important ones for the genus-membership first. Errors: Bison throws feces 7 m for defense Women have less teeth Dayfly has only 4 legs Speculations: Parthenogenesis and other forms of reproduction Procreation (in mud etc. ) – until Pasteur, 19 th century! Brains serve to cool blood Women are incomplete men (more influence of katameria than of sperm) Women get soul later, birth rates m/f have to do with winds

3. Evolutionary ideas until Darwin 3. 1 Some aspects of biology after the middle ages Renaissance: • Excursions, geograph. discoveries, herbaria, museums • flourishing of anatomy (Andreas Vesalius, Fabrica (1543; De humani corporis fabrica libri VIII); public section of corpses; previously unknown exactness; descent-line: apes – “pygmies” (Plinius!) – man) 17 th cent. : • new science of nature (Bacon, Galilei) Experiments (planned variation of conditions, protocols) • New tools of observation: microscope, telescope; discovery of micro-organisms, fine structures, insect development • “Physico-theology” & speculative preformationism (1695) (hot discussions 18 th cent. (Spallanzani), end 1830!)

3. 2 Carl von Linné’s taxonomy • Various attempts to classifications, morphology comes in focus (microscopes!) • Tension: Theory still Aristotelian (tree / pyramid), experience shows multiplicity and similarities across branches • “Natural history” becomes a discipline of its own Carl von Linné (Linnaeus), 1707 -1778; Swedish medic and botanist Reform of taxonomy, 3 merits: a) New system of plants, with classification method (according to number and structure of reproduction organs; “sexual system”) Systema naturae 1735; Genera plantarum 1737 etc. b) Binary nomenclature (instead of descriptions), e. g. Sambucus nigra (sambucus = genus, sambucus nigra = species) c) Terminology for the parts of plants

3. 2 Carl von Linné’s taxonomy Backgrounds of Linné’s thought: Objective structures in nature, ideas of the divine creator. Not Aristotelian essentialism, but rather Enlightenment’s ideal of ordering Does classificatory relatedness imply anything about historical relatedness? Does the Systema point to a relation? Linné understood it as an artificial system with the task of ordering/quick finding; “natural system” as final project at horizon. Growing discontent about Linné´s artificiality. Some unclear remarks about an origin of plants Controversial how firmly he believed in the stability of species

3. 3 Early French speculations about evolution Georges Buffon (Histoire Naturelle, 36 vols. , 1753 -1788): • Complexity and similarities in nature make a Linnéan classification impossible. And: “species” is an abstractum; there are individuals • Procreation and change, by climate etc. Related species might have common ancestors, maybe one. Earth out of a collision sun-comet. • Evolutionary scale/ladder instead of Linné´s hierarchical classification • Evidence: similar anatomy across many species (donkey/horse, man/ape, man’s foot / horse’s foot etc. ); rudimentary, useless organs • Indirect message: EITHER God made the species by variation of few plans (great!), OR they have a common history. (Officially, the first…)

3. 3 Early French speculations about evolution Georges Cuvier (1769 -1832), Étienne Geoffroy Saint-Hilaire (17721844) and the Paris Academy Dispute 1831: Idealist versus evolutionary morphology? Cuvier: “King of functional anatomy”, fine drawings, function determines structure, structure allows conjecture to function. “Reconstruction of died-out animals out of a few bones. ” Four basic construction plans of animals Yet firm opposition to any evolutionary change (cats from Egypt, …) Fossils are just extinct species, in global/regional catastrophes. No “intermediate forms” in fossils Geoffroy St. Hilaire: Research in homologies (e. g. gill bones in fish – ear bones in humans; vertebrate is similar to inverted worm (nerves at back, intestinal at front). Hence, change of species, common ancestry. Political relevance: (1) not ideas of God (2). . . if not even nature is stable?

3. 4 Romanticist Philosophy of Nature and Morphology Johann W. von Goethe (1749 -1832): • “morphology” instead of “comparative anatomy”: plants and animals represent certain ideal shapes/forms/construction plans (mostly superficial, restricted to outer form) • speculations about construction plan of a “Urpflanze” (ideal plant) which is realized in variants in real plants • Postulates that skull bones are modified rib bones • Discovers the intermaxillary bone in human embryos: since humans represent general mammal plan, and all other mammals have it, it must be somewhere… - in embryonal development! “Göttingen School” (Carl Friedrich Kielmeyer, Johann Friedrich Meckel, Lorenz Oken, influenced by Fichte and Schelling): “Recapitulation”: Development of the embryo recapitulates animals of lower complexity • Partly empirical (embryology, anatomy), partly philosophical: “formative power” of nature etc. ; idealist “great chain of beings”

3. 4 Romanticist Philosophy of Nature and Morphology Richard Owen (1848): Theory of “archetypes” (ideal design plans). Background: similar organs in very different animals (mole’s hand & dolphin’s fin have same bones!) cannot be due to environment. Archetype of all vertebrates: Terminological proposal, used till today: Homologous organ: same construction, different function (e. g. mole’s hand, dolphin’s fin) Analogous organ: different construction, same function (e. g. bird’s and butterfly’s wing)

3. 5 The first “evolutionary theory”: Lamarck 1809 Jean Baptiste de Lamarck (1744 -1829): Philosophie zoologique (1809) • • “Lamarckism” today: inheritance of individually acquired characteristics, usually seen as overcome since Darwin; partial revival today First evolutionary theory: a theory that & how species change in the course of time. Simple forms of life emerge constantly from anorganic matter, procreation; hence, no common ancestry Inner tendency to higher development, “complexifying force”: le pouvoir de la vie Organisms adust behaviour to environment and inner state Use/disuse of organs leads to growth/change of organs (e. g. neck) … and that change is inherited! As with Geoffroy St. Hilaire later: politically dangerous ideas…

3. 5 The first “evolutionary theory”: Lamarck 1809 Jean Baptiste de Lamarck (1744 -1829): Philosophie zoologique (1809) – “First Law: In every animal which has not passed the limit of its development, a more frequent and continuous use of any organ gradually strengthens, develops and enlarges that organ, and gives it a power proportional to the length of time it has been so used; while the permanent disuse of any organ imperceptibly weakens and deteriorates it, and progressively diminishes its functional capacity, until it finally disappears. ” – “Second Law: All the acquisitions or losses wrought by nature on individuals, through the influence of the environment in which their race has long been placed, and hence through the influence of the predominant use or permanent disuse of any organ; all these are preserved by reproduction to the new individuals which arise, provided that the acquired modifications are common to both sexes, or at least to the individuals which produce the young. ”

3. 6 Erasmus Darwin (1731 -1802) and a widely forgotten Anonymous: Robert Chambers (1844) Erasmus Darwin (grandfather of Charles Darwin and Francis Galton) Speculative views about Lamarck-style evolution: “Would it be too bold to imagine, that in the great length of time, since the earth began to exist, perhaps millions of ages before the commencement of the history of mankind, would it be too bold to imagine, that all warm-blooded animals have arisen from one living filament, which the great first cause endued with animality, with the power of acquiring new parts, attended with new propensities, directed by irritations, sensations, volitions, and associations; and thus possessing the faculty of continuing to improve by its own inherent activity, and of delivering down those improvements by generation to its posterity, world without end!” Glimpse of natural selection [R. Chambers] Vestiges of the Natural History of Creation (1844) Popular science book, rather speculative, many errors – Author: Robert Chambers, Scotch writer, anonymous – Variability of species; Man descends from simpler forms of life – Popularity and (slowly starting) excitement

4. History of evolutionary thought from Darwin to the present 4. 1 Charles Darwin (1809 -1882) – life and works Son of a religion-skeptic physician & unitarian Studies briefly medicine, natural history, theology; future: parson? No professional education as a scientist (biology not yet established!) Invitation to travel on mapping-ship Beagle 1831 -36 Collects, studies, draws, sends samples home Initially only few doubts about stability of species Influences: Charles Lyell (geologist, big changes of the earth surface; but rejects Lamarckism; species are created; they die out due to external change, and suppression by other species) Richard Owen and Romantics Erasmus Darwin Lamarck (via Robert E. Grant!)

Increasing doubts in Lyell’s biology (not in his geology!): • released domestic animals adapt quickly to new environment • two similar ostrich species in overlapping areas (why does the one not repress the other one? ) • why do species dies out without change in environment? • why are died-out mammals replaced by other, similar ones? • the finches from the Galapagos islands: - related with each other, related with animals on the continent, - different birds in similar habitats! - No clear-cut line “species” - “variety”

Back in Cambridge • • Orders his findings, discusses (with Lyell, Owen, J. Gould (finches!))… Early speculations about an explanation for relations • 1837: first sketch “I think”, insight that species must be changeable Darwin’s speculations still +/- Lamarckist: - changes/variations are always useful, since - adaptation to environment as an embryo, geograph. isolation may cause new species - changes are inheritable • 1838: reads Thomas Malthus: Essay on the Principle of Populations have tendency to grow infinitely, but limited resources cause concurrence and limit growth, • Darwin: Selection not as embryo, but after birth. Theory of natural selection was +/- finished by 1839 (diaries).

The Theory of Natural Selection • Random, undirected, inheritable variations PLUS • natural selection under the pressure of the environment, concurrence for food etc. … • … may in the long run lead to the emergence of adaptive (=useful) change and new species. • I. e. , variations need not be perfect anymore. Old idea of perfect adaptation (from natural theology!) abandoned. Variations need just be slightly better. • A manuscript was finished by 1842. Why not published? (1) Fear of scandal (Vestiges 1844!)? (2) Darwin had not yet a good idea for the ramifications / divergences in the changes. • After 1854: Sympatry (different species in same area) is more important than Allopatry (different species in isolated areas). Coherent with the facts. Reason: Big areas have more ecological niches!

The Publication and its effects 1856 1858 1859 Darwin presents his ideas to Lyell etc. , friends urge to publish Alfred Russel Wallace sends a manuscript to Darwin, similar ideas Common paper by Darwin and Wallace, Wallace admits priority On the Origin of Species by Means of Natural Selection Public effect: In England dampened by a theol. discussion about correct Bible interpretation 1860, and Vestiges John Herschel (astronomer, 1792 -1871): unscientific, since only statistical Thomas Huxley (“Darwin’s Bulldog”) tries to elicit cultural discussion, free universities, no religion Not even whole church opposes. Still: excitement. In France Cuvier dominates, no big interest In Germany: bestseller, quick translation, popularized by Ernst Haeckel (materialist reading!)

Later Publications 1871 1872 The Descent of Man (no big scandal; evolution of moral behavior) The Expression of Emotions in Animals and Man Works about coral reefs, plant fertilisation, rainworms, etc. Darwin and religion: 1851 Death of his daughter, loss of religious faith, respectful agnostic 1882 Tomb in Westminster Abbey

4. 2 The Five Basic Tenets of Darwin’s Darwinism (E. Mayr) • • Evolution: species come and go through time, and while they exist they change. (But: the real bearer of evolution is the individual, not the species!) Common descent Species multiply: the diversification of life involves populations of one species diverging until they become separate species Gradualism: evolutionary change occurs through incremental small steps; new species are not created suddenly. Natural selection: some variants change individual’s survival & reproduction probability. Against Lyell: species are not stable; not perfectly adapted to environment; species are not created quickly (Lyell was a theory of species sequence, not of species evolution!) Against Lamarck: individual changes are not inherited; common descent

4. 3 Darwin’s Speculations about the biological fundament • Notabene: Darwin had no idea about the place and nature of genetic information, laws of inheritance (Mendel’s rules etc. ) • Theory of Pangenesis: all cells produce little “gemmulae” (little buds), they gather in reproduction organs. In the young they mix • = a Lamarckist remainder in Darwin! • Still even in 1868 (book on selective breeding of animals and plants). Soft inheritance, acquired traits are passed on.

4. 4 Some open questions in Darwin • Small steps or jumps? (Is mutation or selection the more important driving force of evolution? ) • Why sudden speeding up of evolutionary change, rapid growth of species numbers in certain stages of earth history (“Cambrian explosion” etc. ) • No real theory about inheritance, similarity and variability • Why is there life at all? No procreation (no conflict with Pasteur 1859); maybe 4 or 5 original forms of life. Reference to creator more courtesy? Speculation about the warm little pond (letter to Hooker 1871): • “But if (and Oh! What a big if!) we could conceive in some warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity etc, present, that a protein compound was chemically formed ready to undergo still more complex changes. . . ” • Similarity to Miller-Urey experiment 1953, “primordial soup” …

The Miller-Urey experiment

4. 5 Ernst Haeckel (1834 -1919): Materialism with idealist traces • • Great graphic illustrator, popularizer in Germany Materialist (Darwinism as anti-religious and anti-conservative program!) • Yet: some idealist remainders, idea of dynamics of growing complexity: – takes on recapitulation-idea of Kielmeyer – Creates terms, and “biogenetic fundamental law”: “ontogeny” repeats “phylogeny” – Evolutionary morphology: similarity of gastrula stage; speculation to a “Gastrea” as common ancestor “tree of life” suggests height of development, dynamics to complexity. (false: successful simple organisms, backward-developments)

4. 6 Francis Galton (1822 -1911): Evolution becomes statistical • • • Cousin of Darwin, multidisciplinary scientist: statistics, fingerprints, efficacy of prayer, questionnaire, blood-transfusion, eugenics Experiments against Darwin’s “gemmulae” semi-lamarckian speculative theory of inheritance • Important: Separation Organism – genetic information (“stirp”). Organism is just a representative selection from stirp, like a parliament • Inheritance becomes statistical matter, every parent contributes ½ • Variation is now a matter of the population (not the organism, not the species!). New subject of evolution. Farewell to Aristotelian ideas. • Beginning of theoretical biology as a mathematicised discipline!

4. 7 August Weismann (1834 -1914): The organism as mere vehicle of genetic information • • • Radical materialist Similar to Galton, but with more empirical justification: experiments with sea urchins (ježinac): germ cells are separated from the rest of the organism in very early stage Separation germ cells – somatic cells • Half-speculative theory of “immortal germ plasm”. • Revolutionary: genetic info is the bearer of variation, not the organism; only “vehicle” Separation: growth/reproduct. “Lamarck finally dead” Cf. Dawkins’ Selfish Gene !! • • •

4. 8 Gregor Mendel (1822 -1884) The first robust theory of inheritance OSA monk and abbot in Brno (CZ). Experiments with peas etc. , publication 1865 in Austrian Journal, no reception. Only from 1900! Question in those times: Does evolution go uniformly or in jumps? Darwin: (Newton’s ideal! Natura non facit saltus!): uniformly Huxley, Galton: undirected, small mutations / variations BUT: such undirected small changes can cause no big changes, since statistics equalizes their effect. Statistical samples tend to average. Hence, there must be other factors, Mutation must be more important. Mendel’s method: reduction to only few (Y/N, not gradual) features, quantification (counting) Experiments with crossing of peas and beans; features: white/lilac flowers; white/red/pink flowers, smooth/wrinkled seed. Result: Mendel’s rules

4. 8 Gregor Mendel (1822 -1884) The first robust theory of inheritance Mendel’s first law (+ some more) Presumptions: unmixable, discrete factors of inheritance mutation more important than selection, bigger jumps are possible But: biometry, statistics show continuous slow change. How can this possibly be harmonized? “Great crisis of Darwinism” in early 20 th century!

4. 9 The Molecular Revolution in Evolutionary Biology End of 19 th century: discovery of chromosomes in cell nucleus 1903/04 Sutton/Boveri: genetic info stored in chromosomes 1910 Johannsen: Terminology “Genotype” (inner constitution, info) “Phenotype” (appearance); Genotype Phenotype! The genotype is inherited, not directly the features!! After 1909 Drosophila experiments (quick reproduction, only 4 x 2 chromos. ) Beginning of localisation of genetic info on chromosomes (chemistry still unknown till 1953!) Insights: - some features controlled by more than one gene - there are interactions between genes - one gene can influence more than one feature HENCE: 1: 1 -matching “genes features” false since early 20 th century! “genetic blueprint” metaphor likewise wrong (still it is around…)

4. 9 The Molecular Revolution in Evolutionary Biology 1953 Watson/Crick: Discovery of double-helix structure of desoxyribonucleic acid (DNA) Since mid-1960: Mechanisms of gene expression (DNA – RNA – proteine synthesis) begin to be clarified “Human genome project” 1990 -2003 Mind the correct way of speaking: “Sequencing the genome”. (Not: “decoding the genetic code” – fallback to blueprint model!)

4. 10 The “Modern Synthesis” (1920 s, 1930 s onwards) Darwinism had no undisturbed victorious career; no uniform development of post-Darwinist biology. Especially Mendel’s genetic discoveries caused worries: quick changes, “either/or” are possible. Mutation is more important! Darwin’s intuition: small, incremental steps, selection is more important “The great crisis of Darwinism” / “Eclipse of Darwinism” (J. Huxley 1942) Late 19 th/ early 20 th century: all 5 tenets of Darwin come under doubt, many biologists step back to older theories, partly speculative. Extension of population genetics (Ronald Fisher, Sewall Wright, John B. S. Haldane): Complex mathematical models to combine Mendel & Darwin Some ideas from population genetics: • On genotype level Mendelian jumps, on phenotype level only small Darwinian changes: since features often depend on many genes! • Population (not individuals) as the unit of evolution, statistics equalize: in some individuals Mendelian jumps, in population slow Darwinian shift • The smaller a population, the easier are big jumps possible.

4. 10 The “Modern Synthesis” % Theodosius Dobzhansky, Ernst Mayr and others: “The Modern Synthesis”, “Synthetic Biology of Evolution”… …connects: Darwinian core idea (stepwise evolution, selection) Mendelian genetics Population genetics Biometry Microbiology Biochemistry Behavioral science Paleontology Geology etc.

4. 11 Some special ingredients of the Modern Synthesis Genetic drift / bottleneck / founder effect (A non-adaptive effect, against pan-selectionism!) Punctuated equilibrium (Eldredge/Gould) Various explanations of stages of stasis and rapid evolutionary change; allopatric origin of species (related with genetic drift) Neutralism (Kimura): many big changes in DNA come and go, without being tested by selection, neutral changes possible %

4. 11 Some special ingredients of the Modern Synthesis % Cooperation between genes; “Regulator genes”, governing the expression of other genes, “genetic switches”. E. g. Hox genes, regulate development of legs, antennas etc. mutations in such genes may have big effects! • • • “Evo-Devo” (Evolutionary developmental biology): similarities in the genotype are astonishingly high across species, but phenotypes differ dramatically! Hence: genes in themselves are not so important Hence: difference must lie in the expression of the genes, development of the organism, regulator genes etc. Evolutionary biology in the past took adult organism (and populations out of them) as subject to natural selection, Evo. Devo takes the whole process/cycle of development of an organism as the subject of natural selection.

5. Evolution: Theory-structures and concepts 5. 1 Theory-structure of EB Physics, chemistry etc. : law-like explanations, able to prediction false predictions a part of falsification Evolutionary biology admits of (almost) no interesting predictions Herschel: “un-scientific”, mere statistical relations (young) Popper: unfalsifiable tenets like “the survival of the fittest”, circular. Partial answer: (1) Parts of explanations admit of predictions (cell level etc. ) Some few experiments with bacteria admit of prediction even of “direction of evolution” on macro-level: in lactose solution, bacteria with mutation develop genes to process lactose (2) Why decreeing that all “scientific” explanation must resemble physics?

5. 2 Is EB a “science”? Not a science like physics; combination of natural & historical disc. Rather: a scientific research program, uniting many disciplines Criteria by Philip Kitcher (The Advancement of Science, 1993) A scientific practice… • Investigates an accepted domain of objects • Investigates accepted problems and questions • Has a non-natural technical terminology • Has commonly shared convictions at its basis • Applies accepted means and methods • Has accepted standards on aim and success of the investigations • Has accepted standards how to accepts results from other sciences • Is part of a social network Evolution biology scores excellently under most criteria!

5. 3 The bearers / objects of evolution Individuals / organisms? Species? Populations? Genetic information? Life-cycles? …different metaphysical views on objects of biology! 5. 4 What are the traits / characteristics / features tested by evolution? a) only bodily features (shape, food tolerances, …) or also behavior? Dawkins: “the extended phenotype” (including behavior) is being tested! b) “Adaptive” traits (with a success story) – “maladaptive” traits – “by-products” c) Is every feature adaptive? Panselectionism. (But: what is a feature? ? ) d) Beware of a frequent misunderstanding concerning “success story of trait”: - not the trait makes its success story (the trait is not there from beginning!) - rather: ex post, we see a success story of the trait and its previous traits (evolution does “bricolage” with available traits!). No “trait essentialism”

5. 5 Misunderstandings “Survival of the fittest”: - Can be incremental; need not be perfect - need not be “the strongest/biggest/…” “Struggle for life”: - is not intra-population struggle - need not be fight with similar species - just general struggle with the ecological conditions: food, climate, safety, nesting-places… 5. 6 “Genes” (… an unsettled debate! “by the genes” is no explanation!) “place on the chromosome”? – surely to imprecise “sequence on the DNA” (concrete gene)? – things are more complicated: are “regulated /switched-on” genes really genes? Coding/non-coding DNA? Some DNA sequences are “read” more than once, some correspond to more than one proteine? Beginning/end sometimes unclear, … “whatever makes a difference in fitness” (abstract, functional gene)? – may come close to antirealism concerning gene & genetic info.

6. “Evolution” between science and world-view 6. 1 Overview SCIENCE: Darwin’s (historical) Darwinism “Darwinism” Synthetic theory of Evolution (1940 onwards) Current EB (“New synthesis”, “Evo. Devo”, …) CONTROVERSIAL: Pan-Selectionism Sociobiology “Cultural Evolution”, “Memetics” NON-SCIENCE: Social Darwinism Pop-Darwinist Slogans

6. 2 Pan-Selectionism Sometimes also: “strict neo-Darwinism”, “Darwinist orthodoxy” (Terminology seems not to be entirely fixed) • Thesis: natural selection is the driving force of evolution; every feature has an “evolutionary success story” behind it • Tendency to a deterministic account of the world and the human being: evolutionary successful features are +/- “hard-wired”, that includes also our mind, our reactions, etc. • Critical evaluation: empirically unplausible in the light of modern genetics • Ironically: a remainder of old “perfect adaptation” ideas (natural theology)

6. 3 Sociobiology • Extension of evolutionary explanations also to our behavior, moral beliefs etc. • First visions already in Darwin: “moral tribes” might be more successful • Example 1: why is altruism evolutionary successful? – At first glimpse: not at all. Risk your life, lose eating-time etc. – Example “whistle-blowing” birds – But kin-selection / group-selection (E. O. Wilson, Sociobiology 1975): brothers/sisters have 50% same genetic info, cousins 25%, … saving the life of, e. g. , 5 cousins by whistle-blowing (and sacrifying own life!) increases the survival of own genetic info! 125 - 100= +25% • Example 2: why are moral norms evolutionary useful? An economic way to secure cooperation of group members, internal/mental control instead of expensive external forces • Critical evaluation: Empirically: unclear evidence • Manifold cultural shapings of behavior, limit natural/cultural unclear • Sociobiol. is no exclusive explanation (“altruism is nothing but xy…”)

6. 4 “Cultural evolution”, “memetics” 1976 Richard Dawkins, The Selfish Gene (and in later books) 1995 Daniel Dennett, Darwin’s Dangerous Idea • Basic idea: behavioral and cultural practices are passed on by imitation, they can be seen as items of “cultural information”: “memes”. Such memes undergo competition and selection, some do propagate, some do not • Examples: termite-poking of chimpanzee tribes; language, use of fire, wheel, wall-graffiti, literary figures, cooking recipes, religion, product designs, business ideas… • Critical evaluation: Suggestive examples… But huge differences between genes and memes: - genes mutate at random, memes often intentionally - genes from distant branches of evolution non mixable, memes are - memes are inherited in Lamarckist ways, individual inventions In sum: misleading metaphor, parasitic on good image of biology. Even dangerous when mixed with ideas of neo-liberalism

6. 5 Social Darwinism Label from 19 th century, roots rather in Thomas Malthus and Herbert Spencer than in Darwin. Basic ideas: (1) Evolutionary explains (and predicts) social facts (2) Evolutionary biology is not only descriptive (what is the case? ), but also normative (what should we do? ) (3) Evolution is progress (4) There are “good” and “bad” genetic information-bits (for that progress!) (5) Progress should not be retarded, “bad” genetic info should be suppressed (handicapped, lower races, …) Usually: rivalry of all against all (people in a society, nations / nations, …), misunderstanding of “struggle for life” Notabene: NS ideology was not closely connected with Darwin. Racism!

6. 5 Social Darwinism Critical evaluation: (1) Is/ought fallacy, description / normativity fallacy / genetic fallacy (2) “Biological basis”of Social Darwinism is dubious and rather Lamarckist: Evolution is progress. But: progress/regress are not biological categories at all (3) It depends on the environment which forms are “progressive / more successful” (small and undemanding animals might be most successful!) I. e. , social Darwinism rests on some aesthetic ideals of what is healthy, strong, progressive etc. (4) Even if we could create a “perfect natural world”, this does not guarantee a pleasant, humane culture. False genetic determinism, nature does not determine culture.

6. 6 Some pop-Darwinist slogans “Nature and Evolution are nothing else but a huge process of chance and random” – BIOLOGICALLY FALSE, at least selection is not random. “Darwinism means that mutation and natural selection explain every feature. ” – BIOLOGICALLY MOST PROBABLY FALSE, only most narrow-minded pan-selectionists would deny other evolutionary effects “Cosmic evolution”: “There is one big evolutionary process from Big Bang to human culture. ” – CONCEPTUAL NONSENSE. (1) Not every agglomeration and development process (as in the early universe) is also an evolution process. There is no multiplication, mutation, inheritance, and selection for protons, galaxies, stars etc. Over-extension of a biological metaphor. (2) On cultural evolution, see 6. 4. %

6. 6 Some pop-Darwinist slogans % “Society and economy work according to evolutionary laws. ” – SEE 6. 4 above! “Science (like biology) consists of falsifiable claims only, worldviews are irrational and subjective. ” – FALSE FROM THE VIEWPOINT OF PHIL. OF SCIENCE. (1) Too narrow concept of “science” (2) Background assumptions are even at work in the sciences: see Kuhn’s paradigms, Lakatos’ “hard cores” of research programs. Border to world-views fuzzy; world-views contain rational structures, can be more/less plausible, and rationally discussable. See Popper: there are genuine philosophical problems, beyond science.

6. 7 Biology and Religion: On “Creationism”, “Intelligent Design” etc. A bit of history USA a country of small religious groups, partly literal reading of the Bible About one half of the population has serious doubts about evolution Empirical fundament: unclear spots in evolution, cosmic fine tuning Spectrum: • Short-time (Young-earth) creationism 6 days, about 6000 yrs ago • Long-time creationism (special creationism) successive intervention • “Intelligent Design” design-plans, to solve irreducible complexity • “Theistic Evolution” (Vatican II; God as 1 st cause carries 2 nd causes) • Deism • Atheism, metaphysical naturalism Wealthy think-tanks, www. discovery. org etc. , disinformation, wedge

6. 7 Biology and Religion: On “Creationism”, “Intelligent Design” etc. Objections to ID • Unclear ontology of “design plan”, at odds with usual scientific ontology • Selective evidence, focused on explanatory gaps and failures of EB • Some irreducible complexities are reducible; regulator-genes etc. may explain complexities • “Filling-the-gap-theology”: every new biological discovery makes God more irrelevant, theology on constant retreat • ID proves only world-constructor (demiurg), not creator • Why a single God behind the 1000’s of appearances of ID? Tacit background theology smuggled in. • Problem of evil radicalized: source of bad design, senseless design? • In sum: neither necessary nor fruitful for the Christian. • (Due!) criticism of reductionism and ideology should not turn into (undue) pseudo-scientific blends of theology and biology.

7. Summary • • • Aristotle inaugurated a vision of biology with the species in focus, and a teleological view at the world – yet, without external design. The raise of modern evolutionary thought began before Darwin and was based on empirical findings as well as on speculative ideas. Darwin and Wallace developed the first coherent, large-scope theory with a broad empirical basis (still with many blind spots). The basic ideas of Darwin are still topical in the core of current EB. However, EB can’t be reduced to “mutation and selection”. Current EB is a research program with many open questions, especially about the impact of natural selection. Central concepts like “gene” admit of different readings. This is one reason why EB has a strong affinity to be reduced to an ideology, more than other sciences. Another reason is the wide scope of EB, from the explanation of shape to behavior. ID is a dubious blend of theology and biology which appears neither necessary nor useful for theologian.

8. Repetition questions 1. 2. 3. 4. 5. 6. How does Aristotle’s conception of science differ from Plato’s? Name 4 of Aristotle’s biological writings and their (rough) content. How does Aristotle’s method in biology resemble/differ from today? What type of discipline is an episteme, what a historia? Why did we describe Aristotle’s biology as „teleology without design“? Sketch Empedocles’s explanation of the origins of life and Aristotle’s counter-argument. 7. Aristotle’s doctrine of the stability of species (what is it? ) is said to have prevented evolutionary ideas for centuries. But are there any traces of variability of species in Aristotle? 8. How did Aristotle describe the development of an embryo? 9. What is preformationism? 10. What is procreationism? 11. What was new about Linné’s taxonomy system? What are its limits? Was he an Aristotelian?

12. What other inventions did he make which are still important for biology? 13. Sketch Buffon’s anti-Linnéan position. 14. What was the Paris Academy Dispute 1831 ultimately about? (Don’t just say “idealist versus evolutionary morphology”, but explain the issue!) 15. What are “homologous” organs, what are “analogous” ones? 16. Explain some of the basic intuitions of Romanticist biologists, and name some important persons. 17. Why can we say that Lamarck presented the first evolution theory? Only under what conditions should something be called an evolution theory? 18. What does crucially distinguish “Lamarckism” from standard evolutionary biology? 19. How did Lamarck explain the change of organisms in the course of time? 20. Name some thinkers and researchers who influenced Darwin! 21. How did Malthus change Darwin’s thought? 22. Why is Darwin’s theory of natural selection no theory of perfect adaptation? 23. What is sympatric, what allopatric origin of new species? 24. How did Ernst Mayr summarize classical Darwinism?

25. Sketch Darwin’s “gemmulae” theory. What was it good for, what was it supposed to explain? 26. List some open problems in Darwin. 27. Why are Haeckel’s tree-diagrams suggestive in a false direction? 28. What does his “biogenetic fundamental law” say? 29. Describe the separation of genetic information from the organism in Galton, Weismann and Dawkins. In what are stirp, germ plasm and selfish gene similar? 30. What new point of view dis Galton bring into biology? Why does this bring a turn away from Aristotelian ideas? 31. Why was the “Weismann barrier” seen as a death-blow to Lamarckism? 32. Why did Mendel’s discoveries shake the Darwinism of his time? What was the worrisome problem? 33. Sketch some main steps in the discovery of genetic information. 34. Why is “we can today decode the genetic code” a problematic way of speaking? 35. Why can population genetics perhaps unite Darwinist and Mendelian ideas? 36. What does “pan-selectionism” claim?

37. Why is the (empirically backed!) idea of genetic drift an argument against pan-selectionism? 38. Try to describe some basic ideas of Evo. Devo. Why is Evo. Devo a remedy against the misconception of a “genetic blueprint”? 39. How do evolutionary explanations differ from physical explanations? 40. Why has evolutionary biology a special structure, different from other natural sciences? 41. What units/bearers of evolution were proposed in the history of biology? 42. Why is it misguided to say “feature F had an evolutionary success story”? 43. What did Darwin mean by “struggle for life”? 44. Sketch different notions of a “gene”. 45. How would socio-biologists explain that altruism is sometimes evolutionary successful, even if it goes to sacrificing one’s life? 46. What is a “meme”? Why is “cultural evolution” a non-starter? 47. Describe the mistakes of “Social Darwinism”. 48. Why is “Intelligent Design” not a wise choice for theologians? GOOD LUCK FOR THE EXAM!