Biology of microbes
Philip A. Geis in Cosmetic Microbiology, 2006
Admittedly, nature has no sentience and therefore cannot actually select or make a choice. Therefore the idea of natural selection is more of an analogy or metaphor akin to a human’s sentient choice of artificial selection or breeding. But metaphors and analogies are powerful ways of thinking and evolution provides an enormous amount of explanatory sense, especially in light of the neo-Darwinian syntheses of such biologists as Ernst Mayr, Sir Ronald Fisher, and Edward Wilson. Nature is not actually “selecting” in the sense of making sentient choices. Instead, it “chooses” purely by serendipity, with the “goal” of any creature being simply to proliferate as best it can whether that occurs through competition or cooperation. Perhaps a far more useful idea than Herbert Spencer’s Victorian idea of survival of the fittest or its equally Victorian corollary of progress via the scala naturae is a more modern concept that takes into account the serendipitous stochasticity of evolution — an idea I shall call Brannan’s corollary: proliferation of the slightly better. Whatever allows a creature to proliferate slightly better is what really matters; not survival and not even being the best!
Evolution, Natural Selection, and Behavior
Gail S. Anderson in Biological Influences on Criminal Behavior, 2019
Humans frequently enter into this process and produce unnatural selection or artificial selection. For example, we have made pets from many animals that were originally wild. Wolves were artificially selected by humans to make their descendants into dogs. Humans chose the friendliest wolf cubs and bred them to other friendly cubs to eventually produce early dogs. They then selected specific traits within the dogs to produce dogs with different functions, such as fighting, hunting, and shepherding. If pet dogs go back to the wild, natural selection takes over after a few generations and produces a wolf-/shepherd-type dog, which is obviously the best type to survive in the wild. However, because we want pet dogs and can provide things that the wild environment does not, such as protection and food, a large variety of dog breeds survive in our society just fine, usually on someone’s bed.
Genetics of muscle mass and strength
Adam P. Sharples, James P. Morton, Henning Wackerhage in Molecular Exercise Physiology, 2022
At the end of this chapter, we will discuss the results of selective breeding and inbred mouse strain studies as a non-biased strategy to identify genes that affect muscle mass and/or strength. Apart from farmers and horse breeders, geneticists have performed selective breeding experiments to (a) identify the cumulative effect of selecting, in the ideal case, all DNA sequence variants within a population that affect muscle size and (b) identify these DNA sequence variants. Selection studies for body weight have also led to an accumulation of genetic variants or alleles that increase or decrease muscle mass, as muscle mass is related to body mass. For example, the gastrocnemius weight in males of the so-called DUH mouse strain that have high body mass is ≈247 mg, whilst the gastrocnemius weight of mice selected for small body weight reaches only ≈66 mg (25). Among the selected alleles, there might be some that affect the growth of all cells such as genetic variations in the growth hormone system and alleles that affect muscle mass specifically such as those in the myostatin-Smad pathway.
Echinacea biotechnology: advances, commercialization and future considerations
Published in Pharmaceutical Biology, 2018
Jessica L. Parsons, Stewart I. Cameron, Cory S. Harris, Myron L. Smith
Conventional selective breeding techniques have traditionally led to the gradual improvement of many plant species. While industry will undoubtedly continue to develop “improved” varieties, published Echinacea breeding studies (and patents) have focused primarily on ornamentals (Ault 2002; Korlipara 2008) and reducing seed dormancy (Qu and Widrlechner 2012). Traditional selective breeding of Echinacea can make use of the existing genetic and phenotypic variation in commercial and wild collected plants and is widely accepted by the public, including within the organic farming industry. Conversely, direct alteration of the genome of a plant through molecular genetic techniques is the most precise way to modify developmental and biosynthetic processes. Whereas public concerns will likely continue to impede the use of Genetically Modified Organisms (GMOs), several potentially “organically acceptable” biotechnological approaches have been developed to modify Echinacea, including transformation with Agrobacterium and the induction of polyploids.
Personhood, Welfare, and Enhancement
Published in The American Journal of Bioethics, 2022
The first problem is that liberal principles are not necessarily respected when selecting persons with highest expected welfare. Think of how eugenicists justified measures such as forcible sterilization with reference to a utilitarian calculation where the short-term pains of administering cruel treatments and of suppressing instincts of sympathy were outweighed by the long-term benefit to the human stock. Similarly, if we stipulate that some type of trait, such as “intelligence,” is an intrinsic good because it raises the welfare of the person involved, one could use utilitarian reasoning to justify the genetic enhancement of such a trait through methods that are equivalent to improving human stock. Of course, there is a significant moral difference between the artificial selection on embryos and the artificial selection on fully developed human beings. Nonetheless, there is nothing in this line of reasoning that should preclude the endorsement of widespread social programs to improve human stock at the embryonic stage.
The application of proteomics in muscle exercise physiology
Published in Expert Review of Proteomics, 2020
Stuart J Hesketh, Ben N Stansfield, Connor A Stead, Jatin G Burniston
Exercise spans a continuum from high-force maximal/singular contractions associated with strength training to sustained periods of lower-intensity contractions associated with endurance exercise (Figure 1). Interval training, involving high-intensity bouts of exercise interspersed by short recovery periods, also develops endurance and is associated with adaptations in aerobic metabolism that afford protection against chronic diseases and the effects of aging. Exercise prescription specifies the intensity, duration, frequency and mode of exercise. Each of these attributes influence the magnitude and nature of the adaptations that occur in the heart and skeletal muscle and, therefore, cannot be ignored when interpreting data or designing exercise interventions. There are also complex interactions between exercise and the genome that may influence either baseline (innate) capacity or an individual’s responsiveness (acquired) to exercise training. As such, an individual’s capacity for exercise is a product of their genetic heritage as well as their recent level of habitual activity. As yet, individual variability in human muscle response to exercise has not been investigated using proteomics. However, bi-directional artificial selection has been used to generate animal models that provide highly useful substrate for investigating innate [17] and acquired [18] differences in aerobic capacity and therefore disease risk and mortality [19].
Related Knowledge Centers
- Animal
- Inbreeding
- Phenotypic Trait
- Sexual Reproduction
- Plant Breeding
- Natural Selection
- Offspring
- Hybrid
- Wheat
- Rice