Is the ‘Trade-off Hypothesis’ Worth Trading For? - …
This not being the case, we examined various trade-offs between brain mass and the mass of other expensive tissues such as gut mass, which is approximated by gut length or diet quality.
Is the 'trade-off hypothesis' worth trading for
I follow Kent Beck in making a distinction between internal and external quality. The pleasantness and effectiveness of a user-interface is external quality as it's something that can be perceived by the users of a system. That is something that can be sensibly involved in a trade off - do I want extra work on making feature A easier to use or should I add feature B?
Trade-offs between fitness related traits are expected to generate negative genetic covariances, unless genetic variance for resource acquisition exceeds that for resource allocation. For what concerns post-copulatory sexual selection, producing competitive ejaculates is costly, however, and it can be attained at the expenses of traits involved in mate acquisition and/or survival, because resources are limited. Alternatively, under a good‐sperm scenario, males that are better equipped for winning sperm competition should also show higher survival and, more generally, perform better than poor sperm competitors. In the guppy (Poecilia reticulata) the number of sperm inseminated is the most important determinant of male fertilization success, therefore to evaluate the evolutionary consequences of male investment in sperm production we performed a bidirectional artificial selection experiment for sperm production in guppies. Contrary to expectation, males selected for high sperm production not only transferred more sperm per copulation, but also grew faster, attained a larger body size, were more colourful, sexually more active and more attractive to females. Sperm velocity and morphology was not affected, but sperm viability increased with sperm number. All the other measured male and female fitness-related traits were unaffected by sperm production. These results suggest that, at least in lab conditions, some guppy genotypes perform better in most life-history traits, acquiring more resources than others.
trade off hypothesis - General Practice Notebook
The trade-off between locomotor costs and brain mass in birds lets us conclude that an analogous effect could have played a role in the evolution of a larger brain in human evolution.">
A Graduate Course in International Trade and Foreign Investment
The amount of fat that people carry is steadily increasing and has reached ‘pandemic’ scales. The adverse effects of obesity are more pronounced in higher grades of obesity and studies addressing the same show increased mortality when the entire spectrum of obesity is taken into account. Since the accumulating evidence favors the survival advantages of lesser degrees of adiposity and its detrimental effect on fertility, the bulging waistline of humans may be explained by this ‘fitness first’ hypothesis, which states that adiposity – overweight and grade 1 obesity – may be an evolutionary adaptation, ultimately aiming for better biological fitness (Figure 1). The decreased fertility associated with adiposity may not be acceptable to an individual, but considering the true definition of fitness – which is a property of the race rather than its individual member – the ability of the gene pool to persevere for a very long time with appropriate trade-offs remains the prime consideration.
Topic 5: Capital structure: trade off theory vs
The trade-off between locomotor costs and brain mass in birds lets us conclude that an analogous effect could have played a role in the evolution of a larger brain in human evolution.
06.01.2012 · Topic 5: Capital structure: trade off ..
Obesity, fertility and resources at large scale from the LHT perspective
The LHT observes that, as reproductive efforts are costly and can compromise growth and survival function, organisms regulate the number of offspring to sustain race depending upon environmental variables such as available resources and mortality rates. Species with a shorter lifespan tend to produce more offspring and those with a long lifespan, like humans, tend to produce fewer offspring. Such trade-offs are central to the principle of LHT and the resulting fitness is subjected to natural selection. ‘Fitness’ in evolutionary terms means the probabilistic function representing the ability of the race to sustain the copies of a gene in the long term and should not be confused with physical fitness (). Fitness can be calculated as the product of the survival probability of offspring to their number. Stable strategies that evolve improve the fitness with several trade-offs, a classical one being between quantity and quality.