Evolutionary Catechism (Evolution)

by dhw, Friday, January 15, 2010, 13:10 (5236 days ago) @ George Jelliss

My thanks to Matt, George and David for three sets of rather different answers to my list of questions. It goes without saying that none of us subscribe to Creationism, but how evolution moves from early forms of life to its present complexities remains a wide open subject. -This is reinforced by a thought-provoking article on the subject ... for which again my thanks to George. He quotes Massimo Pigliucci, who says: "Nobody's going to deny Darwin and all that stuff." But which aspects of Darwin is nobody going to deny? The gradualness of evolution ("Natura non facit saltum", says Darwin), innovation through random mutations and slow modifications, natural selection resulting in new species (as opposed to variations in existing species), absence of intermediate forms due to the imperfection of the geological record?-I think we all accept evolution in some form, but the devil is in the detail, and evolutionary biologists themselves can't agree on that. -Douglas Futuyma says there's "no need to formally revisit the Modern Synthesis". Andreas Wagner says: "If you're interested in evolutionary innovation, you can't get away anymore with a very simple, one-dimensional notion of a phenotype. Now we can recognize that there is a deficiency in the Modern Synthesis."-Here's another stimulating quote: "Genotypes were assumed to translate more or less directly into phenotypes, and evolutionary change stemmed from the slow, gradual accumulation of random genetic mutations. But with the rise of the EvoDevo field [...] this simplified picture is becoming more complex."-Epigenesis also comes under scrutiny:
Vincent Colet: "Epigenetic inheritance is widespread, but that doesn't mean it lasts and causes evolutionarily meaningful effects."
Jerry Coyne: "Usually epigenetic characters aren't inherited past one or two generations."-The more complex the process (and the more disagreements there are among the experts), the more difficult it becomes to justify agendas. -One very useful term also emerges from the article. In my discussions with George, I've repeatedly argued that in addition to being able to replicate, the first forms of life must have had the potential ability to change ... otherwise there could have been no evolution. Now to my delight I find there is an official scientific word for it: EVOLVABILITY.