r-selection:When parents don’t spend a lot or even any time caring for their young, they produce many offspring. This is a reproductive method used to make sure some offspring make it to the next generation. K-selection:Parents that put a lot of time and energy protecting and raising th...
SAN FRANCISCO, March 5 (Xinhua) -- An international team of researchers has found that rain and snow may play a more important role than how hot or cold it is for the evolution of plants and animals. By reviewing 168 published studies that measured natural selection over certain time periods...
Theory shows how sexual selection can exaggerate male traits beyond naturally selected optima and also how natural selection can ultimately halt trait elaboration. Empirical evidence supports this theory, but to our knowledge, there have been no experime
Directional selection leads to increase over time in the frequency of a favored allele. Consider three genotypes (AA,Aaandaa) that vary in fitness such thatAAindividuals produce, on average, more offspring than individuals of the other genotypes. In this case, assuming that the selective ...
O Their descendants will likely be shaped by natural selection to evolve genes that will make them fit to survive the next natural disaster. O Their survival may have been due to chance, but fitness also contributes to their survival over time. ...
potentially favorable gene combinations are often destroyed by indiscriminate environmental forces such as storms, floods, earthquakes, or volcanic eruptions, without natural selection being given the opportunity to favor these genotypes. Yet over time, in the survival of those few individuals that become...
Therefore, natural selection resulting in 'non-survival of the non-fit' leads to spreading of the risk of extinction of the population over genotypes and to the gradual development and accumulation of highly sophisticated adaptations. Only in an environment that has been stationary or even almost ...
Natural selection lacks foresight. It obviously could not anticipate our romantic and parenting needs in the modern era, nor could it “plan ahead” for any of the shifts in adaptive trade-offs occurring over evolutionary time. In consequence, we have a layered attachment system in which older ...
In goat breeds, the domestication followed by artificial selection for economically important traits have shaped genetic variation within populations, leading to the fixation of specific alleles for specific traits. This led to the formation and evolutio
英[ˈnætʃrəl] 美[ˈnætʃrəl] 释义 常用 高考讲解 adj. 自然的;意料之中的;出于本性的;天赋的;轻松自如的;天然的;亲生的;非婚生的;本位音的 n. 有天赋的人 词态变化 复数:naturals; 实用场景例句 全部 自然的 物质的 ...