10.31 allele Refriests - 高级

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• 选择节Aallele Falleetriques - 高级

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  Aallele Falleetriques - 高级

  

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  Why are some rabbits lighter in color?
  ::为什么有些兔子的颜色比较浅?

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  Because of the frequency of the alleles in the population's gene pool . Allele frequency , or how often an allele is found in a gene pool, is related to the expression of that allele.
  ::由于人口基因库中的异灵的频率。 异灵的频率,或基因库中常见的异灵的频率,与该异灵的表达方式有关。

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  Allele Frequencies
  ::千秋千秋千金

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  Our analysis of the rabbit ( Table ) showed that the relative numbers of various alleles are the best measure of variability in a gene pool (or a population). Population geneticists calculate the proportions, or frequencies, of each allele in order to study changes in populations. In fact, a change in allele frequency is the most precise measure of the process of evolution. Recall that genetic variability, as seen through numerous alleles, is the fundamental component for to occur. Without this variability, evolution cannot happen.
  ::我们对兔子的分析(表)表明,各种异灵的相对数量是衡量基因库(或人口)变异性的最佳尺度。 人口基因学家计算每个异灵的比例或频率,以研究人口的变化。 事实上,异灵频率的变化是进化过程的最精确尺度。 回顾从许多异灵中看到的遗传变异性是发生的基本要素。 没有这种变异性,进化不可能发生。

  Table of Phenotypes and Genotypes in Two Rabbit Populations

  Phenotypes	Number of each phenotype	Genotypes	Number of each genotype	Alleles contributed to gene pool	Total gene pool
  播放段落 Rabbit Population #1 ::1号兔子人口	$\begin{align*}90\end{align*}$ $\begin{align*}brown\end{align*}$	$\begin{align*}BB\end{align*}$	$\begin{align*}50\end{align*}$	$\begin{align*}100B\end{align*}$	$\begin{align*}140B\end{align*}$
  		$\begin{align*}Bb\end{align*}$	$\begin{align*}40\end{align*}$	$\begin{align*}40B+40b\end{align*}$	$\begin{align*}\;\end{align*}$
  	$\begin{align*}10\end{align*}$ $\begin{align*}albino\end{align*}$	$\begin{align*}bb\end{align*}$	$\begin{align*}10\end{align*}$	$\begin{align*}20b\end{align*}$	$\begin{align*}60b\end{align*}$
  播放段落 Rabbit Population #2 ::2号兔子人口	$\begin{align*}90\end{align*}$ $\begin{align*}brown\end{align*}$	$\begin{align*}BB\end{align*}$	$\begin{align*}70\end{align*}$	$\begin{align*}140B\end{align*}$	$\begin{align*}160B\end{align*}$
  		$\begin{align*}Bb\end{align*}$	$\begin{align*}20\end{align*}$	$\begin{align*}20B+20b\end{align*}$	$\begin{align*}\;\end{align*}$
  	$\begin{align*}10\end{align*}$ $\begin{align*}albino\end{align*}$	$\begin{align*}bb\end{align*}$	$\begin{align*}10\end{align*}$	$\begin{align*}20b\end{align*}$	$\begin{align*}40b\end{align*}$

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  An allele’s frequency is the fraction (expressed as a decimal) of a population’s gene pool made up of that particular allele. In rabbit population #1 above, the gene pool for coat color included 200 alleles, 140 of which were B. The frequency of allele B for population #1 is 140/200 = 0.7. Because frequencies must total 1.0, and the only other allele is b, the frequency of allele b is 0.3. (Alternatively, we can calculate the frequency of allele b by dividing the number of this allele by the total number of alleles: 60/200 is again 0.3.) In population #2, 160 of 200 alleles are B, so the frequency of allele B is 0.8, and the frequency of allele b is 0.2. What would change if albino rabbits comprised 20% of the population?
  ::Alle 的频率是由该特殊元素组成的人口基因库的分数(以小数表示 ) 。 在上面的兔子群 # 1 , 涂层的基因库包括200个所有者, 其中140个是 B。 人口1 的Alle B 频率是 140/ 200 = 0. 7 。 因为频率必须总共为 1. 0, 而其他唯一的其他偏数是 b , alle b 的频率是 0. 3 。 (另外, 我们可以通过将这个所有元素的数除以所有元素数来计算 Alele b 的频率: 60/200 又是 0. 3 ) 。 在 人口 2, 160 200 个所有元素中的 B, Altele B 的频率是 0. 8 , 而 Alee b 的频率是 0. 2 。 如果白兔占人口的20% , 那会有什么变化呢?

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  If all the members of a rabbit population (#3) are homozygous brown, the frequency of B is 1.0, the frequency of b is 0, and there is no diversity. Allele B is said to be fixed , and until a occurs, no possibility for evolution (with respect to this particular gene) exists. A population with frequencies of 0.5 for B and 0.5 for b would have maximum diversity for this two- gene system. Any change in those frequencies across generations would reflect evolution of the population.
  ::如果兔子人口(第3号)的所有成员都是同质黄瓜,B的频率为1.0,b的频率为0,没有多样性。据说,Alele B是固定的,在出现之前,没有演化的可能性(就这一特定基因而言)。B的频率为0.5,b的频率为0.5,b的频率为0.5,这种双基因系统将具有最大的多样性。这些频率在世代间的任何变化都会反映人口的演变。

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  Summary
  ::摘要

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  • Changes in allele frequency measure the process of evolution.
    ::异频变化测量进化过程。
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  • Allele frequency is the decimal fraction of a population’s gene pool made up of that particular allele.
    ::Allele 频率是人口基因库的十进制分数,该基因库由该特定ele组成。
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  • A gene pool containing only one type of allele is fixed; it lacks variation and potential for evolution, at least until mutation occurs.
    ::固定的基因库只包含一种异差;它缺乏变异和演化潜力,至少直到发生突变为止。
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  • For a gene with two alleles, allele frequencies of 0.5 indicate maximum variation.
    ::对于具有两个异形的基因来说,异形频率为0.5表示最大变异。
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  • Any change in allele frequency reflects evolution of a population.
    ::异频频率的任何变化都反映人口的变化。

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  Review
  ::回顾

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  1. Explain how to determine allele frequencies.
     ::解释如何确定Alele频率。
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  2. Evaluate phenotype, genotype, and allele frequencies as measures of variation, as raw material for evolution, and as a measure of evolution.
     ::评估苯型、基因型和Alle频率,作为变化的衡量尺度,作为进化的原材料,并作为进化的衡量尺度。