适应辐射(Adaptive Radiation)在进化生物学中指的是从原始的一般种类演变至多种多样、各自适应于独特生活方式的专门物种(不包括亚物种,就是说它们相互之间不能交配的物种)的过程。而这些新物种虽然有差别,但却在一定程度上保留了原始物种的某些构造特点。它们各自占据了合适自己的小生境。适应辐射这个概念适用于进化史中一个短的时间段内。 适应辐射是由变异和自然选择所推动的。
化石展示了人们所认知的“适应性辐射”,这也从生物学的角度解释了一定时期内急剧的生物多样性现象,致使个体物种的分化没有被世人所察觉.
The fossils show what is known as an adaptive radiation. This is biology-speak for a period of diversification so fast that the individual splits cannot be distinguished.
强调了极低剂量率电离辐射诱导适应性反应的可能及其剂量效应和时间效应关系的特点。
Emphasis is given to the characteristics of the dose response and time response relationships of adaptive response induced by extremely low dose rate ionizing radiation.
芝加哥消息——即使对于可疑脑梗死这样的适应症,医生也应该注意到检查过程中多排螺旋CT相关的辐射剂量问题。
CHICAGO - Even for indications as serious as suspected stroke, doctors should be aware of the radiation doses being delivered with the multiple ct exams typically delivered during the course of care.
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