Kysymyksiä meemiteoriasta

Olen hiukan hämmentynyt sen suhteen, tarkoittiko Richard Dawkins meemin samanlailaiseksi replikaattoriksi kuin geeni, joka kopioituu samanlaisena (=faithfully) aivoista toiseen.

Dawkinsin työtoveri Susan Blackmore väittää nimittäin Boydin ja Richersonin "Ei pelkästään geeneistä" kirjan kritiikissä, että Dawkins ei edellytä että meemi on samanlainen replikaattori kuin geeni:

Nor do replicators have to be "discrete, faithfully replicating, genelike bits of information". Dawkins long ago pointed out that the copying fidelity of most memes is very low, there is often no right way of deciding where one meme begins and another ends, and most memes do not appear to be particulate – themes later taken up by both Dennett (1995) and me (Blackmore 1999). These facts do not disqualify songs, stories, scientific theories or technologies from being replicators; these memes are just rather poor quality replicators – as we might expect from an evolutionary process that began only a few million years ago at most.

Kulttuurievoluution tämän hetken ykkösnimet Robert Boyd ja Peter Richerson taas kritisoivat meemiteoriaa siitä, että se edellyttää että meemi on replikaattori.

B&R:n mukaan Dawkinsin replikaattorille on nimenomaan ominaista:

a) Fidelity. The copying must be sufficiently accurate that even after a long chain of copies the replicator remains almost unchanged

b) Fecundity. At least some varieties of the replicator must be capable of generating
more than one copy of themselves.

c) Longevity. Replicators must survive long enough to affect their own rate of replication.

Replicators give rise to cumulative adaptive evolution because replicators are targets of natural selection. Genes are replicators — they are copied with astounding accuracy, they can spread rapidly, and they persist throughout the life time of an organism directing its machinery of life. Dawkins thinks that beliefs and ideas are also replicators. On the face of it, this is an apt analogy. Beliefs and ideas can be copied from one mind to another, spreading through a population, controlling the behavior of people who hold them.

Boyd ja Richerson hylkäävät sen että kulttuuri kopioituu niin kuin geenit:

But there are reasons to doubt that beliefs and skills are replicators, at least in the same sense that genes are. Unlike genes, ideas are not transmitted intact from one brain to another. Instead the information in one brain generates some behavior, somebody else observes this behavior, and then (somehow) creates the information necessary to generate very similar behavior. The problem is that there is no guarantee that the information in the second brain is the same as the first. For any phenotypic performance there are potentially an infinite number of rules that would generate that performance. Memes will be transmitted from brain to brain only if most people induce a unique rule from a given phenotypic performance. While this may often be the case, it is also plausible that genetic, cultural, or developmental differences among people may cause them to infer different memes from the same overt behavior. To the extent that these differences shape future cultural change, the replicator model captures only part of cultural evolution.

Boydin ja Richersonin mukaan replikaattorit eivät ole välttämättömiä kumulatiiviselle evoluutiolle.

Blackmore antaa taas ymmärtää että Boyd ja Richerson näkevät eroa oman teoriansa ja meemiteorian välillä sielläkin missä eroa ei todellisuudessa ole:

Could it be that Richerson and Boyd are merely rejecting the word "meme" because of its popular connotations, when their theory is really equivalent to memetics? I have wondered about this for many years, because it is clear that along the spectrum of gene-culture coevolution theories, Boyd and Richerson have always been the closest to memetics; that is, they have come very close to treating their cultural variants as true replicators that evolve in their own way, and without being firmly held on Wilson's genetic leash. So the answer depends on whether Richerson and Boyd think that cultural variants are replicators or not. In this book we have the answer, and it is "no".

Onko siis meemiteorian ja Boydin ja Richersonin välillä ristiriitaa ollenkaan ?

Ehkä ei ole, mutta minusta ainakin sen voi ehdottomasti todeta, että meemiteoria on täysi raakile tai pelkkä intuitiivinen heitto, jos sitä vertaa Boydin ja Richersonin pitkälle kehitetyyn ja matemaattisesti eleganttiin "rakennelmaan".

Toisaalta kunnes toisin osoitetaan, uskon itse, että tietty ristiriita saattaa olla olemassa.