Darwin & Wallace (Evolution)

by dhw, Wednesday, September 30, 2015, 10:58 (3340 days ago)

We have left humans, dogs and oxytocin behind, hence the new thread.-dhw: We believe evolution began when single cells combined. Bacteria survived, but the new forms led to improvement. 
DAVID: I don't think you mean what the sentence says. There was evolution among the first single cells. Archaea came first. Multicellularity came after cyanobacteria and common bacteria appeared in many species.-Thank you for the correction. -DAVID: I don't believe in his [Darwin's] theory.
[DAVID, 21 September: I accept evolution. I have my own theory as to how it works.] 
dhw: I presume you mean you do believe his theory of common descent, but you do not believe his theory of gradualism and random mutations. 
DAVID: Yes, I accept evolution through a form of common descent.-The distinction is important. You believe in parts of Darwin's theory, and you do not believe in other parts. Me too.-DAVID: The concept of evolution was bandied about for most of the century before Darwin. He did not invent the concept that we evolved.
dhw: That does not invalidate the theory. 
DAVID: His theory doesn't explain evolution. He popularized the idea as a chance mechanism while Wallace, who did most of the observation work for him at least recognized the probable need for design. I simply accept the probability of evolution because of the fossil record following a progressive time line. 
dhw: Darwin was travelling the world, observing species and working on his theory long before he knew Wallace. He joined HMS Beagle in 1831, when Wallace was eight years old! In fact it wasn't until 1858 that Darwin realized through their correspondence that Wallace was coming to the same conclusions as himself! Origin was published in 1859. This is not a very fruitful line of discussion, is it?-DAVID: Yes it is. You know they had much correspondence up to 1858. if I'm correct, Darwin did just three years of observation, Wallace many more. And Darwin finally got around to publishing in 1859 to beat Wallace to the punch. I must repeat, Darwin popularized the concept of evolution, a theory which had been around for years. The method of evolution he proposed has never been proven, and remains a tenuous hypothesis to this day. You've agreed to not accepting chance mutation and natural selection. What is left of his proposal is common descent, nothing else.-I don't know what you are referring to by “three years of observation”, and the claim that Wallace “did most of the observation work for him” is probably libellous! Darwin spent most of his life “observing”. The Beagle adventure lasted 5 years, and as you will see from the article I am about to post, he had already conceived his theory of “natural selection as the cause of evolution” by 1838 - when Wallace would have been 15. You and I have agreed, however, (a) that natural selection is not the CAUSE of evolution; and (b) that the method he proposed is dubious. However, I have not rejected natural selection - only the creative powers Darwin and others attribute to it. Natural Selection remains an important element of the theory in so far as it sums up the process that leads from innovation (the real driving force) to the survival or extinction of species. The theory of common descent as Darwin presented it created a furore at the time. You and I and millions of others now take it for granted. Its acceptance is his triumph.
 
In Origin, Darwin acknowledges Wallace several times, along with dozens of other “observers”. That is what we call research. However, your posts have set me googling, and I have found an account of the events that led up to the joint presentation of their work on natural selection in 1858. I find it very revealing and also very moving, and I hope it will give you a rather more sympathetic view of Darwin. It's too long to reproduce here, and so I'll post it separately.