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This attempt to validate gene selectionism by applying it to ants and peacocks fails for three main reasons (which I consider in turn in the rest of this review): 1) the general theory is bankrupt; 2) the two chosen examples form a false and disparate pairing that either does not need or does not fully illustrate the theory; 3) the theory, even if valid in its own limited realm (which it is not), cannot serve as a paradigm for all, or even much, that evolutionary theory must explain.

Since Darwinism is a theory about differential reproductive success ("survival of the fittest" in the old cliché of limited utility), and since organisms are plainly doing the struggling and reproducing "out there" in nature, why would anyone want to relocate the action at the level of genes encased within these organisms?

Natural selection is a theory of "differential reproductive success"; therefore, according to one school of thought followed by Cronin, only natural objects that replicate themselves faithfully can be units of selection. For if an object doesn't replicate itself faithfully, then it cannot be a reliable transmitter of the characteristics that make for superior reproductive success. Now an organism, the traditional "unit of selection" in Darwinism, fails by this criterion because, in sexual reproduction, offspring contain only half the genes of each parent. What good is a replicator that dilutes itself by half in each generation?

it is simply not true that only genes replicate with adequate faithfulness. I accept the point that sexual reproduction dilutes the integrity of organisms in replication. But adequate replication returns at higher levels of the hierarchy—populations and species—because splitting at these levels is analogous to asexual reproduction.

a lower unit (a gene, for example) can't be an exclusive agent if all the action occurs at higher levels (organisms, for example)—and the properties that generate this action are "emergent" characters of the higher level—that is, not a simple summation of features built by the lower units (genes).

all evolution by selection, whatever its level of causation, is recorded by change in the frequencies of genes (the lowest level of the causal hierarchy). Since genes record all changes, some evolutionists have been fooled into assuming that genes therefore cause all changes. But scribes are not agents, and bookkeeping is not causality.

(Genetic drift refers to a random process of increase or decrease in the frequencies of genes in populations. Suppose that only ten individuals exist in a species of beetles, and that three of them carry a favorable gene subject to positive Darwinian selection. An elephant rambles by and squashes half the beetles, including [by chance] all three with the favorable gene [which is now randomly eliminated from the population, despite its Darwinian value].)

You don't need gene selectionism to validate female choice; plain old Darwinian selection on organisms works perfectly well (as Darwin himself recognized in establishing the concept): females, in choosing the most healthy and vigorous males, are bolstering their personal reproductive success—the essence of the Darwinian game.

In the world below organisms, at the scale of changes in nucleotides of the DNA code, Motoo Kimura's theory of neutralism (based on the prevalence of genetic drift, as defined earlier), combined with a better understanding of genetic mechanisms, has demonstrated the neutrality of much, if not most, alteration at minimal magnitude. Selectionists often respond, as Cronin does, that their Darwinian preferences are not thereby compromised because such neutral genetic changes do not alter the external forms of organisms, and therefore couldn't be "seen" by natural selection anyway.

New documentation on the rapidity and intensity of mass extinction (including the event that wiped out dinosaurs) has provided the strongest argument for rejecting Darwinian extrapolation. Darwin clearly understood the threat, and he struggled against the implications of mass extinction in the Origin of Species by trying to deny both their extent and rapidity. He endeavored to spread them out in time and diminish their effects. He attempted to render them as an intensification of ordinary competition (inspired, perhaps, by an increase in rates of change for conventional processes like mountain-building and change in sea level). But if mass extinctions are true breaks in continuity, if the slow building of adaptation in normal times does not extend into predicted success across mass extinction boundaries, then extrapolationism fails and adaptationism succumbs.

punctuated equilibrium is the dominant pattern of evolutionary change in the history of living organisms. This theory, formulated by Niles Eldredge and me in 1972, proposes that the two most general observations made by palentologists form a genuine and primary pattern of evolution, and do not arise as artifacts of an imperfect fossil record. The first observation notes that mostnew species originate in ageological "moment." The second holds that species generally do not change in any substantial or directional way during their geological lifetimes—usually a long period averaging five to ten million years for fossil invertebrate species.

In his second attack, Dennett denigrates the importance of nonadaptive side consequences ("spandrels" in my terminology) as sources for later and fruitful reuse.

spandrels define the major category of important evolutionary features that do not arise as adaptations.

Dennett denies theoretical importance to the roles of contingency and chance in the history of life, a history that hasfew predictable particulars and no inherent directionality, especially given the persistence of bacteria as the most common and dominant form of life on Earth ever since their origin as the first fossilized creatures some 3.5 billion years ago.

Cultural (or memetic) change manifestly operates on the radically different substrate of Lamarckian inheritance, or the passage of acquired characters to subsequent generations. Whatever we invent in our lifetimes, we can pass on to our children by our writing and teaching. Evolutionists have long understood that Darwinism cannot operate effectively in systems of Lamarckian inheritance—for Lamarckian change has such a clear direction, and permits evolution to proceed so rapidly, that the much slower process of natural selection shrinks to insignificance before the Lamarckian juggernaut.

Wright presents no neurological evidence of a brain module for sweetness, and no paleontological data about ancestral feeding. This "just-so story" therefore cannot stand as a "classic example of an adaptation" in any sense deserving the name of science.

But how can we possibly obtain the key information that would be required to show the validity of adaptive tales about an EEA: relations of kinship, social structures and sizes of groups, different activities of males and females, the roles of religion, symbolizing, storytelling, and a hundred other central aspects of human life that cannot be traced in fossils?

Moreover, this interdigitation implies that human cultural change needn't even follow genealogical lines—the most basic requirement of a Darwinian evolutionary process—for even the most distant cultural lineages can borrow from each other with ease. If we want a biological metaphor for cultural change, we should probably invoke infection rather than evolution.

the unconscious struggle among individual organisms to promote their own personal reproductive success

The generally accepted result of natural selection is adaptation—the shaping of an organism's form, function, and behavior to achieve the Darwinian summum bonum of enhanced reproductive success.

But selection cannot suffice as a full explanation for many aspects of evolution; for other types and styles of causes become relevant, or even prevalent, in domains both far above and far below the traditional Darwinian locus of the organism.

developmental biologists have documented an astonishing "conservation," or close similarity, of basic pathways of development among phyla that have been evolving independently for at least 500 million years, and that seem so different in basic anatomy (insects and vertebrates, for example).

the ultras' philosophical manifesto of pure adaptationism

Our problem is that, in many adaptive stories, the protagonist does not show dead-obvious signs of Design

Natural selection does not explain why many evolutionary transitions from one nucleotide to another are neutral, and therefore nonadaptive. Natural selection does not explain why a meteor crashed into the earth 65 million years ago, setting in motion the extinction of half the world's species.

the neutral theory of molecular evolution

Natural selection is evolution's basic crane; all other cranes (sexual reproduction, for example) act as mere auxiliaries to boost the speed or power of natural selection in constructing organisms of good design.

evolution includes so much more than natural selection that it cannot be algorithmic in Dennett's simple calculational sense