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.

Ethical Objections to Evolution in Contemporary Muslim Thought

2010 ◽  
Vol 27 (3) ◽  
pp. 79-92
Author(s):  
David Jalajel
Keyword(s):  
Natural Selection ◽  
Reproductive Success ◽  
Evolutionary Theory ◽  
Ethical Behavior ◽  
Human Beings ◽  
Islamic Theology ◽  
Theory Of Evolution ◽  
Ethical Norms ◽  
Differential Reproductive Success ◽  
Survival Of The Fittest

Muslim creationists often argue that the theory of evolution is inherently unethical, claiming that concepts such as natural selection, survival of the fittest, and differential reproductive success promote behaviors like selfishness, violence, and sex- ual promiscuity. This article explores the distinctions made by classical Islamic theologians between God’s actions and human- ity’s actions and their potential to address ethical objections to evolution. The question is examined with reference to two theological traditions: the Ash`ari and the Salafi. The first one distinguishes between God’s creation of actions and humanity’s acquisition (kasab) of actions. According to this approach, ethical valuation is understood to be an attribute of human volitional action. The second approach, followed by Ibn Taymiyyah, Ibn al-Qayyim, Ibn Abu al-`Izz, and others of the so-called Salafi tradition, distinguishes between God’s existential (kawni) will and legislative (shar`i) will. According to it, ethical valuation is restricted to the domain of what God legislates for His volitional creatures. Although these approaches differ in how they contextualize ethical behavior, both of them place ethical valuation strictly within the context of human volitional action. As a consequence, God’s actions in creation (and therefore what is observed in nature) can neither be taken as a pattern for determining ethical norms nor judged according to the ethical norms appropriate for human beings. The paper concludes that by making these distinctions, classical Islamic theology has the potential to effectively counter ethical objections to evolutionary theory.

scholarly journals Selfish Genes, Pleiotropy and the Origin of Recombination

Genetics ◽  
1998 ◽  
Vol 149 (4) ◽  
pp. 2089-2097 ◽  
Author(s):  
Jody Hey
Keyword(s):  
Natural Selection ◽  
Simple Model ◽  
Computer Simulations ◽  
Recombination Rate ◽  
Evolutionary Origin ◽  
Deleterious Mutations ◽  
Beneficial Mutations ◽  
Selfish Genes ◽  
Simple Interaction

Abstract If multiple linked polymorphisms are under natural selection, then conflicts arise and the efficiency of natural selection is hindered relative to the case of no linkage. This simple interaction between linkage and natural selection creates an opportunity for mutations that raise the level of recombination to increase in frequency and have an enhanced chance of fixation. This important finding by S. Otto and N. Barton means that mutations that raise the recombination rate, but are otherwise neutral, will be selectively favored under fairly general circumstances of multilocus selection and linkage. The effect described by Otto and Barton, which was limited to neutral modifiers, can also be extended to include all modifiers of recombination, both beneficial and deleterious. Computer simulations show that beneficial mutations that also increase recombination have an increased chance of fixation. Similarly, deleterious mutations that also decrease recombination have an increased chance of fixation. The results suggest that a simple model of recombination modifiers, including both neutral and pleiotropic modifiers, is a necessary explanation for the evolutionary origin of recombination.

scholarly journals Does natural selection favour taller stature among the tallest people on earth?

2015 ◽  
Vol 282 (1806) ◽  
pp. 20150211 ◽  
Author(s):  
Gert Stulp ◽  
Louise Barrett ◽  
Felix C. Tropf ◽  
Melinda Mills
Keyword(s):  
Natural Selection ◽  
Reproductive Success ◽  
The Netherlands ◽  
Child Survival ◽  
Average Height ◽  
Tall Stature ◽  
Age At First Birth ◽  
Number Of Children ◽  
The North ◽  
Rate Of Increase

The Dutch are the tallest people on earth. Over the last 200 years, they have grown 20 cm in height: a rapid rate of increase that points to environmental causes. This secular trend in height is echoed across all Western populations, but came to an end, or at least levelled off, much earlier than in The Netherlands. One possibility, then, is that natural selection acted congruently with these environmentally induced changes to further promote tall stature among the people of the lowlands. Using data from the LifeLines study, which follows a large sample of the population of the north of The Netherlands ( n = 94 516), we examined how height was related to measures of reproductive success (as a proxy for fitness). Across three decades (1935–1967), height was consistently related to reproductive output (number of children born and number of surviving children), favouring taller men and average height women. This was despite a later age at first birth for taller individuals. Furthermore, even in this low-mortality population, taller women experienced higher child survival, which contributed positively to their increased reproductive success. Thus, natural selection in addition to good environmental conditions may help explain why the Dutch are so tall.

What is the Evolutionary Advantage of Migraine?

Cephalalgia ◽  
2002 ◽  
Vol 22 (8) ◽  
pp. 624-632 ◽  
Author(s):  
E Loder
Keyword(s):  
Nervous System ◽  
Natural Selection ◽  
Environmental Factors ◽  
Genetic Factors ◽  
Evolutionary Perspective ◽  
Defence Mechanism ◽  
Design Constraint ◽  
Trade Off ◽  
Evolutionary Advantage ◽  
Evolutionary Explanations

Susceptibility to migraine is determined by genetic factors and is therefore subject to the forces of natural selection. Migraine is a common and ancient disorder whose prevalence may be increasing, suggesting that a migraine-prone nervous system may be associated with reproductive or survival advantages. Five evolutionary explanations are reviewed that might account for the persistence of migraine: (i) migraine as a defence mechanism; (ii) migraine as a result of conflict with other organisms; (iii) migraine as result of novel environmental factors; (iv) migraine as a trade-off between genetic harms and benefits; and (v) migraine as a design constraint. An evolutionary perspective on migraine allows the generation of important hypotheses about the disorder and suggests rewarding possibilities for further research.

scholarly journals Mismatch induced speciation in Salmonella : model and data

2006 ◽  
Vol 361 (1475) ◽  
pp. 2045-2053 ◽  
Author(s):  
Daniel Falush ◽  
Mia Torpdahl ◽  
Xavier Didelot ◽  
Donald F Conrad ◽  
Daniel J Wilson ◽  
...  
Keyword(s):  
New Species ◽  
Natural Selection ◽  
Dna Sequence ◽  
Computer Simulations ◽  
De Novo ◽  
Sequence Data ◽  
Biological Species ◽  
Species Boundaries ◽  
Population Subdivision ◽  
Geographical Population

In bacteria, DNA sequence mismatches act as a barrier to recombination between distantly related organisms and can potentially promote the cohesion of species. We have performed computer simulations which show that the homology dependence of recombination can cause de novo speciation in a neutrally evolving population once a critical population size has been exceeded. Our model can explain the patterns of divergence and genetic exchange observed in the genus Salmonella , without invoking either natural selection or geographical population subdivision. If this model was validated, based on extensive sequence data, it would imply that the named subspecies of Salmonella enterica correspond to good biological species, making species boundaries objective. However, multilocus sequence typing data, analysed using several conventional tools, provide a misleading impression of relationships within S. enterica subspecies enterica and do not provide the resolution to establish whether new species are presently being formed.

Laboratory comparison of the relative success of Biomphalaria glabrata stocks which are susceptible and insusceptible to infection with Schistosoma mansoni

Parasitology ◽  
1983 ◽  
Vol 86 (2) ◽  
pp. 335-344 ◽  
Author(s):  
D. J. Minchella ◽  
P. T. Loverde
Keyword(s):  
Life Cycle ◽  
Natural Selection ◽  
Reproductive Success ◽  
Natural Populations ◽  
Biomphalaria Glabrata ◽  
Selective Advantage ◽  
Controlled Conditions ◽  
Plausible Answer ◽  
Major Objection ◽  
Transmit Disease

SUMMARYA method of interrupting the life-cycle of the human blood fluke Schistosoma by increasing the proportion of genetically insusceptible intermediate host snails in natural populations was first proposed nearly 25 years ago. The method assumes that insusceptible snails will be at a selective advantage over susceptible snails when the schistosome parasite is present, and therefore natural selection will act to increase the proportion of alleles for insusceptibility. A major objection to the proposed technique is ‘If insusceptible snails are at a selective advantage, then why are they not predominant in natural populations that transmit disease?’ One explanation of this paradox is that insusceptibility may be associated with a disadvantageous character or a physiological defect. This study tests this hypothesis by measuring the relative reproductive success of susceptible and insusceptible snails under controlled conditions. Results indicate that insusceptible (unsuitable) snails are negatively affected in the presence of either susceptible snails or schistosome parasites. Furthermore, in the presence of both susceptible snails and schistosome parasites, insusceptible snails are selectively disadvantaged compared to susceptible snails. These results obtained under laboratory-controlled conditions suggest a plausible answer as to why insusceptible snails are not predominant in natural populations that transmit disease.

scholarly journals Genome-wide analysis identifies genetic effects on reproductive success and ongoing natural selection at the FADS locus

2020 ◽  
Author(s):  
Iain Mathieson ◽  
Felix R. Day ◽  
Nicola Barban ◽  
Felix C. Tropf ◽  
David M. Brazel ◽  
...  
Keyword(s):  
Natural Selection ◽  
Reproductive Success ◽  
European Ancestry ◽  
Age At First Birth ◽  
Hormone Regulation ◽  
Number Of Children ◽  
Two Generations ◽  
Reproductive Ageing ◽  
Children Ever Born ◽  
Using Data

AbstractIdentifying genetic determinants of reproductive success may highlight mechanisms underlying fertility and also identify alleles under present-day selection. Using data in 785,604 individuals of European ancestry, we identify 43 genomic loci associated with either number of children ever born (NEB) or childlessness. These loci span diverse aspects of reproductive biology across the life course, including puberty timing, age at first birth, sex hormone regulation and age at menopause. Missense alleles in ARHGAP27 were associated with increased NEB but reduced reproductive lifespan, suggesting a trade-off between reproductive ageing and intensity. As NEB is one component of evolutionary fitness, our identified associations indicate loci under present-day natural selection. Accordingly, we find that NEB-increasing alleles have increased in frequency over the past two generations. Furthermore, integration with data from ancient selection scans identifies a unique example of an allele—FADS1/2 gene locus—that has been under selection for thousands of years and remains under selection today. Collectively, our findings demonstrate that diverse biological mechanisms contribute to reproductive success, implicating both neuro-endocrine and behavioural influences.

Human self-selection as a mechanism of human societal evolution: A critique of the cultural selection argument

2021 ◽  
pp. 136843102110497
Author(s):  
Shanyang Zhao
Keyword(s):  
Natural Selection ◽  
Reproductive Success ◽  
Social Research ◽  
Cultural Adaptations ◽  
Neolithic Revolution ◽  
Cultural Selection ◽  
Self Selection ◽  
New Type ◽  
Fitness Criterion ◽  
Societal Evolution

Natural selection is the main mechanism that drives the evolution of species, including human societies. Under natural selection, human species responds through genetic and cultural adaptations to internal and external selection pressures for survival and reproductive success. However, this theory is ineffective in explaining human societal evolution in the Holocene and a cultural selection argument has been made to remedy the theory. The present article provides a critique of the cultural selection argument and proposes an alternative conception that treats human self-selection as an emergent mechanism of human societal evolution characterized by a new type of selection pressure and a separate fitness criterion. Specifically, the evolution of human societies is divided into two major periods, each driven by a different mode of selection: natural selection acting on genes and cultures for survival and reproductive success prior to the Neolithic Revolution, and human self-selection acting on cultures – and potentially genes as well – for thrival and prosperous living after the Neolithic Revolution. The conditions for the transition from the first mode of selection to the second and the implications of this transition for social research are also discussed.

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