Darwinian Evolution by the Natural Selection of Heritable Variation: Definition of Parameters and Application to Social Behaviors

2017 ◽  
pp. 140-158 ◽  
Author(s):  
James M. Cheverud
Heredity ◽  
2019 ◽  
Vol 124 (2) ◽  
pp. 263-273
Author(s):  
Daniel J. Fairbanks

AbstractMendel and Darwin were contemporaries, with much overlap in their scientifically productive years. Available evidence shows that Mendel knew much about Darwin, whereas Darwin knew nothing of Mendel. Because of the fragmentary nature of this evidence, published inferences regarding Mendel’s views on Darwinian evolution are contradictory and enigmatic, with claims ranging from enthusiastic acceptance to outright rejection. The objective of this review is to examine evidence from Mendel’s published and private writings on evolution and Darwin, and the influence of the scientific environment in which he was immersed. Much of this evidence lies in Mendel’s handwritten annotations in his copies of Darwin’s books, which this review scrutinises in detail. Darwin’s writings directly influenced Mendel’s classic 1866 paper, and his letters to Nägeli. He commended and criticised Darwin on specific issues pertinent to his research, including the provisional hypothesis of pangenesis, the role of pollen in fertilisation, and the influence of “conditions of life” on heritable variation. In his final letter to Nägeli, Mendel proposed a Darwinian scenario for natural selection using the same German term for “struggle for existence” as in his copies of Darwin’s books. His published and private scientific writings are entirely objective, devoid of polemics or religious allusions, and address evolutionary questions in a manner consistent with that of his scientific contemporaries. The image that emerges of Mendel is of a meticulous scientist who accepted the tenets of Darwinian evolution, while privately pinpointing aspects of Darwin’s views of inheritance that were not supported by Mendel’s own experiments.


2002 ◽  
Vol 25 (3) ◽  
pp. 422-423 ◽  
Author(s):  
Peter A. van der Helm

Implicitly, Wynn's target article starts from the transformational definition of symmetry. Unlike his suggestion, this traditional definition and the recent holographic definition are relevant to the discussion on the cognitive evolution of visual symmetries. These definitions reveal underlying properties and, thereby, they support the natural selection hypothesis. The holographic definition even agrees with an indirect test of this hypothesis.


2005 ◽  
Vol 143 (4) ◽  
pp. 245-254 ◽  
Author(s):  
S. L. PHILLIPS ◽  
M. S. WOLFE

Heritable variation is at the heart of the process of evolution. However, variation is restricted in breeding for uniform crop populations using the pedigree line approach. Pedigree lines are successful in agriculture because synthetic inputs are used to raise fertility and control weeds, pests and diseases. An alternative method promoted for exploring the value of variation and evolutionary fitness in crops is to create composite cross populations. Composite cross populations are formed by assembling seed stocks with diverse evolutionary origins, recombination of these stocks by hybridization, the bulking of F1 progeny, and subsequent natural selection for mass sorting of the progeny in successive natural cropping environments. Composite cross populations can provide dynamic gene pools, which in turn provide a means of conserving germplasm resources: they can also allow selection of heterogeneous crop varieties. The value of composite cross populations in achieving these aims is dependent on the outcome of mass trials by artificial and natural selection acting upon the heterogeneous mixture. There is evidence to suggest that composite cross populations may be an efficient way of providing heterogeneous crops and of selecting superior pure lines for low input systems characterized by unpredictable stress conditions.


2018 ◽  
Vol 115 (16) ◽  
pp. 4006-4014 ◽  
Author(s):  
W. Ford Doolittle ◽  
S. Andrew Inkpen

Many practicing biologists accept that nothing in their discipline makes sense except in the light of evolution, and that natural selection is evolution’s principal sense-maker. But what natural selection actually is (a force or a statistical outcome, for example) and the levels of the biological hierarchy (genes, organisms, species, or even ecosystems) at which it operates directly are still actively disputed among philosophers and theoretical biologists. Most formulations of evolution by natural selection emphasize the differential reproduction of entities at one or the other of these levels. Some also recognize differential persistence, but in either case the focus is on lineages of material things: even species can be thought of as spatiotemporally restricted, if dispersed, physical beings. Few consider—as “units of selection” in their own right—the processes implemented by genes, cells, species, or communities. “It’s the song not the singer” (ITSNTS) theory does that, also claiming that evolution by natural selection of processes is more easily understood and explained as differential persistence than as differential reproduction. ITSNTS was formulated as a response to the observation that the collective functions of microbial communities (the songs) are more stably conserved and ecologically relevant than are the taxa that implement them (the singers). It aims to serve as a useful corrective to claims that “holobionts” (microbes and their animal or plant hosts) are aggregate “units of selection,” claims that often conflate meanings of that latter term. But ITSNS also seems broadly applicable, for example, to the evolution of global biogeochemical cycles and the definition of ecosystem function.


Author(s):  
P. M. Lowrie ◽  
W. S. Tyler

The importance of examining stained 1 to 2μ plastic sections by light microscopy has long been recognized, both for increased definition of many histologic features and for selection of specimen samples to be used in ultrastructural studies. Selection of specimens with specific orien ation relative to anatomical structures becomes of critical importance in ultrastructural investigations of organs such as the lung. The uantity of blocks necessary to locate special areas of interest by random sampling is large, however, and the method is lacking in precision. Several methods have been described for selection of specific areas for electron microscopy using light microscopic evaluation of paraffin, epoxy-infiltrated, or epoxy-embedded large blocks from which thick sections were cut. Selected areas from these thick sections were subsequently removed and re-embedded or attached to blank precasted blocks and resectioned for transmission electron microscopy (TEM).


1998 ◽  
Vol 43 (4) ◽  
pp. 263-264
Author(s):  
Joseph F. Rychlak

Author(s):  
Maria Ciaramella ◽  
Nadia Monacelli ◽  
Livia Concetta Eugenia Cocimano

AbstractThis systematic review aimed to contribute to a better and more focused understanding of the link between the concept of resilience and psychosocial interventions in the migrant population. The research questions concerned the type of population involved, definition of resilience, methodological choices and which intervention programmes were targeted at migrants. In the 90 articles included, an heterogeneity in defining resilience or not well specified definition resulted. Different migratory experiences were not adequately considered in the selection of participants. Few resilience interventions on migrants were resulted. A lack of procedure’s descriptions that keep in account specific migrants’ life-experiences and efficacy’s measures were highlighted.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Li-Yun Lin ◽  
Hui-Ying Huang ◽  
Xue-Yan Liang ◽  
Dong-De Xie ◽  
Jiang-Tao Chen ◽  
...  

Abstract Background Thrombospondin-related adhesive protein (TRAP) is a transmembrane protein that plays a crucial role during the invasion of Plasmodium falciparum into liver cells. As a potential malaria vaccine candidate, the genetic diversity and natural selection of PfTRAP was assessed and the global PfTRAP polymorphism pattern was described. Methods 153 blood spot samples from Bioko malaria patients were collected during 2016–2018 and the target TRAP gene was amplified. Together with the sequences from database, nucleotide diversity and natural selection analysis, and the structural prediction were preformed using bioinformatical tools. Results A total of 119 Bioko PfTRAP sequences were amplified successfully. On Bioko Island, PfTRAP shows its high degree of genetic diversity and heterogeneity, with π value for 0.01046 and Hd for 0.99. The value of dN–dS (6.2231, p < 0.05) hinted at natural selection of PfTRAP on Bioko Island. Globally, the African PfTRAPs showed more diverse than the Asian ones, and significant genetic differentiation was discovered by the fixation index between African and Asian countries (Fst > 0.15, p < 0.05). 667 Asian isolates clustered in 136 haplotypes and 739 African isolates clustered in 528 haplotypes by network analysis. The mutations I116T, L221I, Y128F, G228V and P299S were predicted as probably damaging by PolyPhen online service, while mutations L49V, R285G, R285S, P299S and K421N would lead to a significant increase of free energy difference (ΔΔG > 1) indicated a destabilization of protein structure. Conclusions Evidences in the present investigation supported that PfTRAP gene from Bioko Island and other malaria endemic countries is highly polymorphic (especially at T cell epitopes), which provided the genetic information background for developing an PfTRAP-based universal effective vaccine. Moreover, some mutations have been shown to be detrimental to the protein structure or function and deserve further study and continuous monitoring.


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