Talk:History of evolutionary thought/Archive 3

Archive 1

Archive 2

Archive 3

Zirkle and al-Jahiz

I've managed to get access to the 1941 Zirkle paper we'd cited, and it doesn't fully support what was said. It does give Zirkle's opinion that al-Jahiz describes the struggle for existence, but the quoted passage gives a rather odd view of that struggle so I've given extensive extracts. Perhaps that can be reduced while remaining clear that this doesn't much resemble the views of Malthus, de Candolle or Darwin. Having looked at this discussion, I've deleted stuff which seems to be sourced via newspaper articles from a wikipedia quotation originally based on a radio interview with Gary Dargan, a palaeontologist and a practising Muslim. Not a scholarly source. . dave souza, talk 20:58, 26 June 2013 (UTC)

Lamarck's Impact

How could "favorable variations" occur?

Darwin tried to answer this question from the standpoint of the primitive understanding of science at that time. According to the French biologist Chevalier de Lamarck (1744-1829), who lived before Darwin, living creatures passed on the traits they acquired during their lifetime to the next generation. He asserted that these traits, which accumulated from one generation to another, caused new species to be formed. For instance, he claimed that giraffes evolved from antelopes; as they struggled to eat the leaves of high trees, their necks were extended from generation to generation. Darwin also gave similar examples. In his book The Origin of Species, for instance, he said that some bears going into water to find food transformed themselves into whales over time.

However, the laws of inheritance discovered by Gregor Mendel(1822-84) and verified by the science of genetics, which flourished in

the twentieth century, utterly demolished the legend that acquired traits were passed on to subsequent generations. Thus, natural selection fell out of favor as an evolutionary mechanism. --Azreenm (talk) 16:27, 9 December 2013 (UTC)

You seem to have confused "use and disuse inheritance", as Darwin called it, with natural selection which does not require that imagined mechanism. While Darwin didn't know how favourable variations occur, he knew from research that [random] heritable variations occur, and those that are favourable are those most likely to survive – hence natural selection. The purposeful "self-help" aspect of Neo-Lamarckian inheritance made it popular around the start of the 20th century, but it was discredited when the modern synthesis between genetics and natural selection showed how mutations and Mendelian inheritance provided the variations and the system of inheritance that worked with natural selection. By the way, Darwin Online provides readilly accessible online copies and transcriptions of all Darwin's works, and Lamarck's main concept was of a drive to improvement, with heritable variations as a secondary mechanism. In some ways, Lamarck's concept had already been proposed by Darwin, and rejection by reputable scientists muted its impact. . . dave souza, talk 16:58, 9 December 2013 (UTC)

William Paley got it right...for a short while

William Paley actually appeared to consider something very close to the idea of natural selection, but rejected his own speculation in later paragraphs. It can be argued that he either invented the idea or discovered the idea, even though he ultimately preferred alternative explanations.

"...the eye, the animal to which it belongs, every other animal, every plant, indeed every organized body which we see, are only so many out of the possible varieties and combinations of being, which the lapse of infinite ages has brought into existence; that the present world is the relict of that variety: millions of other bodily forms and other species having perished, being by the defect of their constitution incapable of preservation, or of continuance by generation." [source info lost, sorry]

Powerful stuff, written before Darwin. --104.33.73.250 (talk) 08:45, 21 May 2014 (UTC)

Such reasoning would have been known to both Paley and Darwin as much older. Aristotle reports such arguments as already old in his time. I notice that your quote was reported on NYT. If you put quotes around the words and search on google you will find the original on archive.org and I think this is a wonderful example of why we should not cherry pick quotes, even if from the NYT. Here are the following words from Paley: Now there is no foundation whatever for this conjecture in any thing which we observe in the works of nature ; no such experiments are going on at present; no such energy operates, as that which is here supposed, and which should be constantly pushing into existence new varieties of beings. So it seem that like Aristotle, he was only describing an old theory that he disagreed with.--Andrew Lancaster (talk) 11:32, 21 May 2014 (UTC)

Morgan diagram

Is the Morgan diagram an adaptation from his 1919 book? I could not find an illustration in the book that exactly matches the one uploaded by user 'Electric goat'. Book source: https://www.stmarys-ca.edu/sites/default/files/attachments/files/The_Physical_Basis_of_Heredity.pdf Alan G. Archer (talk) 20:32, 15 November 2014 (UTC)

Plato and the principle of Plenitude

Concerning the following in our article, 2 remarks:

The creator created all conceivable forms of life, since "... without them the universe will be incomplete, for it will not contain every kind of animal which it ought to contain, if it is to be perfect." This "principle of plenitude"—the idea that all potential forms of life are essential to a perfect creation—greatly influenced Christian thought.

1. (I also posted this comment on our Principle of Plenitude article.) I notice that in Wikipedia (actually not only in this article) the principle is treated as if it were creationist. Actually it was in classical times often associated with the arguments against creationism: a large number of planets increases the chances that one of them has life on it for example. See for example David Sedley's book on classical creationism, part of which is on Google Books.
2. As Sedley also explains, Plato, even in the myth form he was using, did not assert that the demiurge created fixed forms for every species. He even implied that all the lower animals are devolved from humans, who were closer to what the demiurge was trying to make.

I notice that as a source we have a footnote which apparently equally applies to 7 other places in this article, which is not normally a good sign for WP:VERIFIABILITY.--Andrew Lancaster (talk) 08:57, 9 April 2015 (UTC)