Reversibility Of Evolution Research Articles

‘Retaining their bestial character’: Fashion, fear of degeneration and animal protection in late imperial Russia

Abstract This article examines the possible roots of the change in cultural attitudes, due to which fashionable objects of animal origin started to be viewed negatively in Russian fashion periodicals and advice manuals of the early twentieth century. Among these influences, we may count the development of the animal protection movement, with the Russian Society for the Protection of Animals established in 1865. Although initially this association was not concerned with fashion, it shaped the notion of the cruel treatment of animals, drawing public attention to this issue. An analysis of non-fiction writing by Fyodor Dostoevsky and Vikentii Veresaev will show that, while the Society’s agenda was ambiguous and met with a mixed response, the new sensibilities this group promoted were increasingly internalized by the educated public. On the other hand, fashion criticism during the era argued that fashion distorts and deforms human shape by giving it animal features – that is, it assists degeneration. A reversal of evolution, in this case triggered by brutality, was similarly evoked by the proponents of animal protection. The newly perceived inappropriateness of certain fashionable objects was thus due to the double ‘animality’ they were believed to impart to the wearer: that of following the ‘fashion instinct’ and that of being complicit in violence.

From chloroplast to the nucleus and back again

Recent data suggest that alterations of biosynthetic pathways could guide plants to produce more of a desired dietary component. In this case, tobacco produced ten times its usual amount of tryptophan, an amino acid often in short supply in the human diet. Scientists inserted a gene encoding the enzyme that controls tryptophan production into the chloroplast genome. The approach is essentially a reversal of evolution. ‘The biosynthesis of tryptophan and other essential amino acids occurs in these plastids,’ said author Archie R. Portis, Jr, a University of Illinois crop scientist. ‘However, the genes encoding these enzymes are located in the nucleus and the proteins are imported into the plastids.’ Plastids in today's plants are believed to have evolved some 2 billion years ago from a unicellular, photosynthetic cyanobacteria that was engulfed by non-photosynthetic cells. ‘Most of the genes originally located in these early plastids moved to the nucleus,’ Portis said. ‘It is likely that those required for tryptophan biosynthesis were among these.’ The gene the researchers inserted was isolated previously from a tobacco suspension culture that had been selected for resistance to an inhibitor of tryptophan biosynthesis. (Zhang, X.H. et al. [2001] Plant Physiology 127, 131–141) PL

Perspective: reverse evolution.

For some time, the reversibility of evolution was primarily discussed in terms of comparative patterns. Only recently has this problem been studied using experimental evolution over shorter evolutionary time frames. This has raised questions of definition, experimental procedure, and the hypotheses being tested. Experimental evolution has provided evidence for multiple population genetic mechanisms in reverse evolution, including pleiotropy and mutation accumulation. It has also pointed to genetic factors that might prevent reverse evolution, such as a lack of genetic variability, epistasis, and differential genotype-by-environment interactions. The main focus of this perspective is on laboratory studies and their relevance to the genetics of reverse evolution. We discuss reverse evolution experiments with Drosophila, bacterial, and viral populations. Field studies of the reverse evolution of melanism in the peppered moth are also reviewed.

Variation in the reversibility of evolution.

How reversible is adaptive evolution? Studies of microbes give mixed answers to this question. Reverse evolution has been little studied in sexual populations, even though the population genetics of sexual populations may be quite different. In the present study, 25 diverged replicated populations of Drosophila melanogaster are returned to a common ancestral environment for 50 generations. Here we show that reverse evolution back to the ancestral state occurs, but is not universal, instead depending on previous evolutionary history and the character studied. Hybrid populations showed no greater tendency to undergo successful reverse evolution, suggesting that insufficient genetic variation was not the factor limiting reverse evolution. Adaptive reverse evolution is a contingent process which occurs with only 50 generations of sexual reproduction.

Reversibility in Evolution: A Maximum Likelihood Approach to Character Gain/Loss Bias in Phylogenies

Reversibility in Evolution: A Maximum Likelihood Approach to Character Gain/Loss Bias in Phylogenies

From Whale Toes to Snake Eyes: Comments on the Reversibility of Evolution

Journal Article From Whale Toes to Snake Eyes: Comments on the Reversibility of Evolution Get access Daniel G. Blackburn Daniel G. Blackburn Department of Anatomy, New York State College of Veterinary Medicine, Cornell UniversityIthaca, New York 14853 Search for other works by this author on: Oxford Academic PubMed Google Scholar Systematic Biology, Volume 33, Issue 2, June 1984, Pages 241–245, https://doi.org/10.1093/sysbio/33.2.241 Published: 01 June 1984 Article history Received: 14 November 1983 Accepted: 30 December 1983 Published: 01 June 1984

From Whale Toes to Snake Eyes: Comments on the Reversibility of Evolution

From Whale Toes to Snake Eyes: Comments on the Reversibility of Evolution

Representations of the body surface in cortical areas 3b and 1 of squirrel monkeys: comparisons with other primates.

Microelectrode multiunit mapping techniques were used to determine the somatotopic organization of postcentral parietal cortex in the squirrel monkey Saimiri sciurus. Recordings were largeLy confined to architectonic areas 3b and 1. Results were compared to those from similar studies of owl (Merzenich et al., '78) and macaque (Nelson et al., '80) monkeys. As in these previous investigations, separate representations of the body surface were found in areas 3b and 1 of squirrel monkeys. These representations were organized in parallel, so that both proceeded from the tail on the medial wall of the cerebral hemisphere, to the lips and oral cavity on the lateral margin of these areas along the sylvian fissure. The representations were also roughly mirror images of each other so that whatever skin surface was represented rostrally in area 3b was represented caudally in area 1, and similar skin surfaces were represented along the common border. However, the representations were not identical. For example, the split representations of the leg differed so that the distal leg was represented in cortex lateral to that devoted to the foot in area 1 and medial to the foot in area 3b. Remarkably, the representations of some body parts were reversed in orientation in both area 3b and area 1 in squirrel monkeys as compared to owl and macaque monkeys. The face, arm, trunk, and leg representations were all reversed in squirrel monkeys, while the orientations of the hand and foot representations were the same. For example, the dorsal trunk is trunk is represented at the 3b/1 border in owl and macaque in area the ventral trunk is represented at th 3b/1 border in squirrel monkeys. These reversals of somatotopic organization in part but not all of the representations in areas 3b and 1 suggest that both fields are divided into sectors where the basic somatotopic orientation is independently determined, that the orientation of some of these sectors is subject to reversal in evolution, and that matching sectors in areas 3b and 1 are not independent in somatotopic organization.

Geographical and Ecological Notes on Cisandine to Platine Frogs

From the point of view of the frog fauna, the great Eastern or Cisandine to Platine Subregion of South America, west of the Andes and north of Bahia Blanca, can be divided into 4 provinces. They correspond roughly to the 4 divisions proposed by Humboldt and by Martius (1840-1849): Hylaea (Naiiades), Continental Province (Oreades and Hamadryades), Platine-Cisplatine Province (Napeae) and Atlantic Province (Dryades). The Northern Hylaea and its known frogs are rather homogenous. The Continental Province can be subdivided into a Chaquean, a Northeastern and a Planaltine Subprovince. The Cisplatine-Platine Province whose southern limits are vague may be divided into Oriental and Mesopotamic Subprovinces. The Atlantic Province stretches along the southeastern and eastern coast. It comprises 4 life-zones: maritime scrub (Restinga), coastal lowlands (Baixada), montane rain-forest and alpine meadows (Hochstaudenwiesen). A fifth disjointed province might be formed by grouping together the different continental orographic systems, such as the Maritime Escarpment of Brazil and the inland parallel sierras, the mountains that separate the Brazilian shield from that of the Guianas, the ranges between Brazil and Venezuela and even the Andes. The Cisandine to Platine frog fauna is only partly generalized. It presents osteological specializations that seem like a reversal of evolution; it also shows caenogenetic innovations that give the impression of frustrated attempts to attain the direct development of the higher classes of vertebrates.

Reversal of Evolution in the Genus Penstemon

The hypothesis that evolution is reversible and that widely divergent germplasms may be returned to a common gene pool is offered. Methods of combining germplasms of reproductively isolated species through an intermediary species as a vehicle are discussed. The gene pool that combines germplasms of a number of divergent species is considered as a source of new divergent lines which the worker may use to simulate natural evolutionary processes.

Meristic Variation and Reversibility of Evolution

PROJECTING into the nasal fossa of any generalized metatherian or eutherian mammal is a series of turbinals, namely, a naso-turbinal (Fig. A, ns.t.), a maxillo-turbinal (mx.t.) and four ethmo-turbinals (I–IV), and there can be little doubt that such an arrangement characterized the remote ancestors of the Primates. But in all primitive Primates (from which we exclude the Lemures), including such forms as Tarsius (Fig. B), Hapale, Chrysothrix (Saimiri), Cebus and Lagothrix, there are but two ethmo-turbinals (I, II), for in these forms the orbital cavities have so enlarged as to obliterate by their approximation the posterior part of the ancestral nasal fossa. In the baboon, gibbon (Fig. C), chimpanzee and gorilla, and in man, the nasal fossae are again enlarged, partly at least as a result of the growth in width of the skull-base in support of an enlarged brain, and in all these forms three1, and in man sometimes four2 or even five3, ethmo-turbinals may be developed. The phylogenetic trend in Primates seems, therefore, to have been towards a reduction of the turbinal series in early forms and a secondary expansion thereof in certain of their descendants.

Reversibility of Evolution

I HAVE read with deep interest the report of the lecture by my old friend, Prof. H. Fairfield Osborn, on “Tertiary Man”, published in NATURE of Jan. 11. In this lecture Prof. Osborn stresses very strongly Dollo's principle of the irreversibility of evolution; that is, the doctrine that once a structure has been lost by an animal through disuse, even if changed circumstances should again make it useful it cannot be revived.