Angelo
3 posts
Feb 08, 2023
6:25 PM
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The two principles established by Geoffrey are still the criteria for determining homologous phenomena. The first principle is the principle of connections, which means that when it is difficult to determine whether the structures of different organisms (such as fish and mammals) are homologous, "the only principle that can be applied is determined by the location, connection and dependence o f these organs or structures, that is to say, whether they are homologous or not." Determined by what I call the principle of relationship. When the function of a structure changes greatly due to functional transformation, Jeffery said that this principle is a reliable indicator, because "an organ can degenerate, atrophy and destroy, but it can not change its position." For example, the skull is always located between the shoulder joint and the forearm bones (radius and ulna). The other is the auxiliary composition principle,Ultrasonic nano dispersion, which says that all homologous structures or organs are composed of the same elements, which is conducive to the element identification of a series of structures. Current modern methods for identifying serial homology in vertebrates or arthropods are based on Jeffery's principles. Jeffery's reputation might have been higher if he hadn't come up with some bizarre ideas. There is no doubt that Geoffrey was greatly influenced by the writings of Okun and other German natural philosophers and idealists. This led him to oppose Cuvier and to extend the principle of uniformity of design to all animals, both vertebrates and invertebrates. In this way he accepted Goethe's idea that there was only one primitive type in the whole animal kingdom. Jeffery and some of his younger friends claimed that by turning the squid upside down and partially inside out, the anatomy of the whale (a mollusk) could be "homologous" (in modern parlance) to the anatomy of vertebrates. It's like what Jeffrey said,ultrasonic sonochemistry machine, "Every animal is either inside or outside of its spine." In a public debate in Paris before the debate of the Academy of Sciences on February 15, 1830, Cuvier categorically rejected this view. Jeffery did not distinguish between similarity due to kinship and similarity due to function (convergence). Cuvier summed up his argument as follows: "Cephalopods have nothing to do with anything.". They are not the product of the evolution of other animals, nor will they develop into another group of animals superior to them. This defeated Jeffery, who had said that he could reduce Cuvier's four groups into one. Cuvier believed that function determined structure. Jeffery, on the contrary, insists that structure determines function. "If there is a change in structure, it will cause a change in function, ultrasonic handheld welder ,ultrasonic generator driver," Jeffery said. Animals have no habits other than those formed by their organic structures. If the structure of the organs is changed, all their motives, all their faculties, and all their actions are likewise changed " (Russell, 1916:77).". Bats are forced to live in the air because of the change of their hands. The thoroughly non-biological assumption that structure precedes function was strangely revived by some mutationists after 1900. Between 1900 and 1910, cuenot, de vry, and Bateson claimed that organisms were constantly undergoing mutations, some of which allowed them to "pre-adapt" to new behaviors and adaptive shifts. There are many original ideas in Jeffrey's article. His "balance principle" States that there is a finite amount of matter present in development, and that if one structure grows, another must shrink in order to maintain a precise balance. The atrophy of one organ is beneficial to another organ. The reason for this is simply that the supply of material needed for each particular requirement is not unlimited. Later, Roux's "organ competition" A struggle of the parts is a revival of this idea (also mentioned by Goethe in 1807) and supported by Huxley and Ren Xi in modern times, with the only difference being the use of modern Chinese language: selective pressure. Richard Owen Owen (1804-1892) was the last famous idealist morphologist before Darwin.
His major work, Archetypes and Homologies of the Vertebrate Skeleton (1848), attempted to establish an internally consistent theory of morphology. The system of this book includes Cuvier's teleology, Geoffrey's principle of relation, Okun's view of continuous repetition of organs, and some aspects of Lamarck's duality of evolution (static view). He took the archetypal concept to its extreme, with vertebrate archetypes divided into segments, including even the entire skull. In order to establish the homology of each bone in the vertebrate skull, he specially formulated a complex vocabulary for them, many of which are still used today, although Owen's theory has long been forgotten. Another kind of technical term proposed by Owen is also far-reaching. One of the greatest weaknesses of the writings of idealists is that most of their conclusions are based on comparative similarities. They made no distinction, however, as to whether the similarity was due to functional similarity or to a seemingly different but more fundamental similarity that Cuvier had long known. Owen distinguished the two similarities as follows: "analogue, a structure or organ of one animal that has the same function as another structure or organ of a different animal." Homologue. The same organ in different animals has different morphology and function. The difficulty,ultrasonic dispersion machine, of course, is to decide what is the same and how, and Jeffery's principle of relationship is particularly useful in this regard. Homology and common ancestry. fycgsonic.com
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