Charles Darwin and the Theory of Natural Selection
            . By Edward B. Poulton. New York, The Macmillan Co. 1896.

Abstract In Descent of Man, Charles Darwin noted the impact of political institutions on natural selection. He thought that institutions such as asylums or hospitals may deter natural selection; however, he did not reach a decisive answer. Questions remain as to whether the selective impacts of political institutions, which in Darwin’s terms may be referred to as “artificial selection,” are compatible with natural selection, and if so, to what extent. This essay argues that currently there appears to be an essential mismatch between nature and political institutions. Unfitted institutions put exogenous and disproportionate pressures on living beings. This creates consequences for what is postulated as the condition of basic equivalence, which allows species and individuals to enjoy similar chances of survival under natural circumstances. Thus, contrary to Darwin’s expectations, it is sustained that assumed natural selection is not discouraged but becomes exacerbated by political institutions. In such conditions, selection becomes primarily artificial and perhaps mainly political, with consequences for species’ evolutionary future.

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‘Short-Spanned Living Creatures’: Evolutionary Perspectives in Rhoda Broughton’s Not Wisely, but Too Well (1867)

Journal of Victorian Culture ◽

10.1093/jvcult/vcaa040 ◽

2021 ◽

Author(s):

James Aaron Green

Keyword(s):

Natural Selection ◽

Evolutionary Theory ◽

Simple Structure ◽

Charles Darwin ◽

Origin Of Species ◽

Charles Lyell ◽

Crystal Palace ◽

The Status ◽

The Individual ◽

Evolutionary Perspectives

Abstract In Geological Evidences of the Antiquity of Man (1863), Charles Lyell appraised the distinct contribution made by his protégé, Charles Darwin (On the Origin of Species (1859)), to evolutionary theory: ‘Progression … is not a necessary accompaniment of variation and natural selection [… Darwin’s theory accounts] equally well for what is called degradation, or a retrogressive movement towards a simple structure’. In Rhoda Broughton’s first novel, Not Wisely, but Too Well (1867), written contemporaneously with Lyell’s book, the Crystal Palace at Sydenham prompts precisely this sort of Darwinian ambivalence to progress; but whether British civilization ‘advance[s] or retreat[s]’, her narrator adds that this prophesized state ‘will not be in our days’ – its realization exceeds the single lifespan. This article argues that Not Wisely, but Too Well is attentive to the irreconcilability of Darwinism to the Victorian ‘idea of progress’: Broughton’s novel, distinctly from its peers, raises the retrogressive and nihilistic potentials of Darwin’s theory and purposes them to reflect on the status of the individual in mid-century Britain.

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Cryptic variation and its manifestation in the Lower Trentonian Rafinesquina lineage (Ordovician, New York State)

The Paleontological Society Special Publications ◽

10.1017/s2475262200008522 ◽

1992 ◽

Vol 6 ◽

pp. 292-292

Author(s):

Robert Titus

Keyword(s):

New York ◽

Genetic Variation ◽

Natural Selection ◽

New York State ◽

Ecological Factors ◽

Stabilizing Selection ◽

Rapid Population Growth ◽

York State ◽

Cryptic Variation ◽

Adaptive Peak

Species populations commonly carry a great deal of genetic variation which is not expressed in individual phenotypes. Cryptic variation can be carried in recessive alleles, in cases of heterosis, or where modifier genes inhibit expression of the hidden trait. Other genetic and ecological factors also allow cryptic variation. Stabilizing selection prevents the expression of hidden traits; normalizing selection weeds out the deviants and canalizing selection suppresses their traits. Together the two keep the species near the top of the adaptive peak. Cryptic variation balances a species' need to be well-adapted to its environment and also for it to maintain a reserve of variation for potential environmental change. Expression of cryptic traits is rare and is usually associated with times of greatly reduced natural selection and rapid population growth, when the lower slopes of the adaptive peak are exposed.A possible example of the manifestation of cryptic traits occurs within the lower Trentonian Rafinesquina lineage of New York State. The two most commonly reported species of the genus have been reappraised in terms of cryptic variation. Extensive collections of Rafinesquina “lennoxensis” reveal far more intergrading morphotypes than had hitherto been recognized. The form which Salmon (1942) described is broadly U-shaped with sulcate margins. It grades into very convex forms as well as sharply-defined or convexly geniculate types. Of great importance, all forms grade into the flat, U-shaped, alate R. trentonensis, which is, by far, the most common and widespread lower Trentonian member of the genus. The R. “lennoxensis” assemblage has a very narrow biostratigraphy, being confined to a few locations in the upper Napanee Limestone. This places it in a quiet, protected, low stress, lagoonal setting behind the barrier shoal facies of the Kings Falls Limestone.The R. “lennoxensis” assemblage does not constitute a natural biologic species; it is reinterpreted as an assemblage of phenodeviants occupying a low stress, low natural selection lagoon facies. All such forms should be included within R. trentonensis. Given the evolutionary plasticity of this genus, extensive cryptic variation is not surprising.

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