Natural Selection on Two Seed‐Size Traits in the Common Morning GloryIpomoea purpurea(Convolvulaceae): Patterns and Evolutionary Consequences

1998 ◽  
Vol 152 (2) ◽  
pp. 188-203 ◽  
Author(s):  
Laura Mojonnier
Keyword(s):  
Natural Selection ◽  
Seed Size ◽  
The Common ◽  
Evolutionary Consequences

Evolutionary social science beyond culture

2006 ◽  
Vol 29 (4) ◽  
pp. 356-356
Author(s):  
Harold Kincaid
Keyword(s):  
Social Sciences ◽  
Natural Selection ◽  
Social Science ◽  
Social Processes ◽  
The Social ◽  
Social Explanations ◽  
The Common

Mesoudi et al.'s case can be improved by expanding to compelling selectionist explanations elsewhere in the social sciences and by seeing that natural selection is an instance of general selectionist process. Obstacles include the common use of extreme idealizations and optimality evidence, the copresence of nonselectionist social processes, and the fact that selectionist explanations often presuppose other kinds of social explanations.

A Simplified Bioenergetics Model of a Hammerhead Shark for Teaching Natural Selection

2019 ◽  
Vol 81 (2) ◽  
pp. 115-119
Author(s):  
Jay Y. S. Hodgson
Keyword(s):  
Natural Selection ◽  
Reproductive Success ◽  
Computer Simulations ◽  
Trade Off ◽  
Bioenergetics Model ◽  
Hammerhead Shark ◽  
Differential Reproductive Success ◽  
Evolutionary Consequences ◽  
Successful Predation

Students often have difficulty understanding the underpinning mechanisms of natural selection because they lack the means to directly test hypotheses within the classroom. Computer simulations are ideal platforms to allow students to manipulate variables and observe evolutionary outcomes; however, many available models solve the scenario for the users without revealing the evolutionarily significant calculations. I developed a simplified bioenergetics model of a hammerhead shark for teaching natural selection that allows the users to manipulate variables and see the impacts of modeling while solving for the evolutionary consequences. Students generate variation within the population by controlling cephalofoil widths and swimming speeds of an individual, which affect its ability to detect and capture prey at the expense of energy lost as drag from swimming. The trade-off between energy gained from successful predation and energy lost from metabolic expenditures dictates rates of reproduction. By manipulating a subset of factors that influence differential reproductive success, students gain an improved understanding of natural selection.

scholarly journals Stability-based sorting: The forgotten process behind (not only) biological evolution

2017 ◽  
Author(s):  
Jaroslav Flegr ◽  
Jan Toman
Keyword(s):  
Natural Selection ◽  
Biological Evolution ◽  
Evolutionary Process ◽  
Static Stability ◽  
Main Process ◽  
Strict Sense ◽  
Broad Distribution ◽  
Evolutionary Consequences ◽  
Insight Into

AbstractNatural selection is considered to be the main process that drives biological evolution. It requires selected entities to originate dependent upon one another by the means of reproduction or copying, and for the progeny to inherit the qualities of their ancestors. However, natural selection is a manifestation of a more general persistence principle, whose temporal consequences we propose to name “stability-based sorting” (SBS). Sorting based on static stability, i.e., SBS in its strict sense and usual conception, favours characters that increase the persistence of their holders and act on all material and immaterial entities. Sorted entities could originate independently from each other, are not required to propagate and need not exhibit heredity. Natural selection is a specific form of SBS—sorting based on dynamic stability. It requires some form of heredity and is based on competition for the largest difference between the speed of generating its own copies and their expiration. SBS in its strict sense and selection thus have markedly different evolutionary consequences that are stressed in this paper. In contrast to selection, which is opportunistic, SBS is able to accumulate even momentarily detrimental characters that are advantageous for the long-term persistence of sorted entities. However, it lacks the amplification effect based on the preferential propagation of holders of advantageous characters. Thus, it works slower than selection and normally is unable to create complex adaptations. From a long-term perspective, SBS is a decisive force in evolution—especially macroevolution. SBS offers a new explanation for numerous evolutionary phenomena, including broad distribution and persistence of sexuality, altruistic behaviour, horizontal gene transfer, patterns of evolutionary stasis, planetary homeostasis, increasing ecosystem resistance to disturbances, and the universal decline of disparity in the evolution of metazoan lineages. SBS acts on all levels in all biotic and abiotic systems. It could be the only truly universal evolutionary process, and an explanatory framework based on SBS could provide new insight into the evolution of complex abiotic and biotic systems.

scholarly journals Variation and evolution of alkaloid complex in yellow lupine (Lupinus luteus L.) during domestication

2013 ◽  
Vol 33 (2) ◽  
pp. 177-195 ◽  
Author(s):  
Wiktor Święcicki ◽  
Konrad Jach
Keyword(s):  
Natural Selection ◽  
Central Europe ◽  
Lupinus Luteus ◽  
Cross Breeding ◽  
Total Level ◽  
Common Opinion ◽  
Primitive Forms ◽  
The Common ◽  
New Form ◽  
Yellow Lupine

A colection of 178 primitive and cultivated forms of <em>Lupinus luteus</em> was analysed with respect to composition and level of alkaloids in seeds. A considerable quantitative and qualitative variation in alkaloids was found in the analysed forms. All analysed primitive forms, not cultivated in Central Europe, contained gramine and lupinine; the majority had sparteine as well. Contrary to the common opinion, yellow lupine has three basic alkaloids, i.e. gramine, lupinine and sparteine. Moreover, a large number of primitive forms showed traces of unidentified alkaline compounds with alkaloid characteristics. It appears that in the course of introduction of yellow lupine to central Europe, the composition and level of its alkaloids have been gradually changing. Their reproduction and natural selection remarkably decreased the number of forms containing gramine as well as the total level of alkaloids in seeds. Cross breeding and screening for low alkaloid bearing forms significantly decreased the total level of gramine as well as the number of forms containing gramine and almost entirely eliminated traces of unidentified alkaloids. One new form was found to have sparteine and only a little of lupinine (total level of alkaloids 0,04%).

Which is Better?

2013 ◽  
pp. 196-205
Author(s):  
Kazi Mostafa ◽  
Innchyn Her ◽  
Jonathan M. Her
Keyword(s):  
Natural Selection ◽  
Stability Margin ◽  
The Body ◽  
The Other ◽  
Common Belief ◽  
Walking Machines ◽  
The Common

Natural multiped gaits are believed to evolve from countless generations of natural selection. However, do they also prove to be better choices for walking machines? This paper compares two surefooted gaits, one natural and the other artificial, for six-legged animals or robots. In these gaits four legs are used to support the body, enabling greater stability and tolerance for faults. A standardized hexapod model was carefully examined as it moved in arbitrary directions. The study also introduced a new factor in addition to the traditional stability margin criterion to evaluate the equilibrium of such gaits. Contrary to the common belief that natural gaits would always provide better stability during locomotion, these results show that the artificial gait is superior to the natural gait when moving transversely in precarious conditions.

Strike-induced chemosensory searching by the anguid lizard Elgaria coerulea

1995 ◽  
Vol 16 (2) ◽  
pp. 147-156 ◽  
Author(s):  
William E. Cooper
Keyword(s):  
Natural Selection ◽  
Phylogenetic Relationships ◽  
Common Ancestor ◽  
Strong Association ◽  
Tongue Flick ◽  
Widespread Occurrence ◽  
Single Origin ◽  
Phylogenetic Inertia ◽  
The Common ◽  
Limited Duration

AbstractStrike-induced chemosensory searching (SICS), including a post-strike elevation in tongue-flick rate (PETF) and searching movements following experimental removal of prey from the predator's mouth, is demonstrated to occur in an anguid lizard, Elgaria coerulea. This finding confirms predictions based on the previously established widespread occurrence of SICS in scleroglossan (especially autarchoglossan) lizard families and on a strong association between SICS and active foraging. Reasons why SICS should be favored by natural selection in active foragers are discussed, but the presence of SICS in anguids is attributed to phylogenetic inertia rather than adaptation. SICS was statistically significant only during the first two minutes in E. coerulea. Its limited duration in an anguid and much greater duration in helodermatids, varanids, and snakes suggest that prolonged SICS may have had a single origin in the common ancestor of Varanoidea or, much less likely, of (Varanoidea + Xenosauridae). Uncertainties about origins due to missing data on certain taxa and to unresolved phylogenetic relationships within Seleroglossa are discussed.

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