D. People plant different types of flowers in a garden. 相关知识点: 试题来源: 解析 C。解析:自然选择是指生物在生存斗争中适者生存、不适者被淘汰的现象。C 选项中昆虫对杀虫剂产生抗性是因为在使用杀虫剂的环境中,具有抗药性的昆虫能够生存下来并繁殖后代,这是自然选择的一个例子。A 选项是人工选择;B...
he raised the initiatives of joining with others to build a Silk Road Economic Belt and a 21st Century Maritime Silk Road (Belt and Road Initiative, or BRI). The
Thus, both genetic and demographic processes in selfing populations should lead to a decrease in the efficacy of natural selection and an increase in the fixation of slightly deleterious mutations, with important consequences for genome evolution. The accumulation of deleterious mutations may also be ...
1.D 事 细节题根据第二 中的"Natural selection usually takes hundreds or even thousands of years to occur. For the peppered moth, this process occurred comparatively quickly.”以及第三段中的 "Within 50 years, the peppered moth went from being mostly light-colored to being mostly dark-colored....
different directions of natural selection. At the same time, no matter how often nonadaptive variations may arise under any given conditions of variation, they will be eliminated and will exert no influence on the direction of selection. Thus, variability alone cannot determine the direction of ...
It’s important to know two different types of memory: long-term and working memory. Long-term memories are a broad category of memories that involve knowledge and experiences stored in the brain for extended periods. On the other hand, thoughts in working memory, whose certain characteristics ...
This was described by Darwin for indigenous New Zealand species of animals and plants, which died out when competing species from Europe were introduced. 1/14 The phrase “mechanisms of natural selection”in the passage is closest in meaning to A types of natural selection B dangers of ...
In nineteenth-century England, certain types of peppered moths were able to better blend (融合) into their surroundings. During that time period, great changes were happening in Great Britain. The Industrial Revolution was part of this change, and with it came air pollution. Natural selection oft...
no selection; (d) studying changes over many generations in the mean of a character in a population; and (e) methods for studying selection in relationship to mating.From the review it becomes obvious that it has proved to be very difficult to obtain unequivocal evidence of natural selection....
1.Natural competition in natural selection Fig.1 In the history of evolution of all species, including human beings, natural competition is seemed as the main driving force which compelled species to survive in the selection of nature. In this section we will discuss the competition in natural ...