5.19 哈迪温贝格
Section outline
-
What you will learn
::你会学到什么-
What is the
Hardy-Weinberg theorem
::哈迪温伯格的定理是什么? -
When is a
in
Hardy-Weinberg equilibrium
::何时在哈代温贝的平衡中
Why is balance important?
::为什么平衡很重要?To these individuals, the importance of maintaining balance is obvious. If balance, or equilibrium, is maintained within a population's genes , can evolution occur? No. But maintaining this type of balance today is difficult.
::对这些人来说,保持平衡的重要性是显而易见的。 如果平衡或平衡在人口基因中得以维持,那么进化能否发生? 不。 但今天维持这种平衡是困难的。The Hardy-Weinberg Theorem
::哈迪温贝格理论Godfrey Hardy was an English mathematician. Wilhelm Weinberg was a German doctor. Each worked alone to come up with the founding principle of . Today, that principle is called the Hardy-Weinberg theorem . It shows that allele frequencies do not change in a population if certain conditions are met. Such a population is said to be in Hardy-Weinberg equilibrium . The conditions for equilibrium are:
::Godfrey Hardy是一位英国数学家。Wilhelm Weinberg是一位德国医生。每个人都独自工作,提出创始原则。今天,这一原则被称为Hardy-Weinberg理论。它表明,如果满足某些条件,人口频率不会改变。据说,这样的人口处于Hardy-Weinberg的平衡状态。平衡的条件是:-
No new
are occurring. Therefore, no new
are being created.
::没有出现新的情况。 因此,没有出现新的情况。 -
There is no
. In other words, no one is moving into or out of the population.
::没有。 换句话说,没有人进入或离开人口。 -
The population is very large.
::人口非常多。 -
Mating
is at random in the population. This means that individuals do not choose mates based on
genotype
.
::在人口中,配对是随机的,这意味着个人不选择基于基因型的伴侣。 -
There is no
. Thus, all members of the population have an equal chance of reproducing and passing their genes to the next generation.
::因此,所有人口成员都有平等的机会复制他们的基因,并将其基因传给下一代。
These five conditions rarely occur in nature. When one or more of the conditions does not exist, then evolution can occur. As a result, allele frequencies are constantly changing, and populations are constantly evolving. As mutations and natural selection occur frequently in nature, it is difficult for a population to be at genetic equilibrium. When all these conditions are met, allele frequencies stay the same. Genotype frequencies also remain constant. In addition, genotype frequencies can be expressed in terms of allele frequencies, as the Table shows.
::这五个条件在性质上很少发生。当一个或一个以上条件不存在时,就会发生演变。结果,所有频率都在不断变化,人口也在不断变化。随着突变和自然选择经常发生,人口很难达到遗传平衡。当所有这些条件得到满足时,所有频率保持不变。热亚型频率也保持不变。此外,基因型频率可以用所有频率表示,如表所示。Hardy and Weinberg used mathematics to describe an equilibrium population ( p = frequency of A , q = frequency of a , so p + q = 1): p 2 + 2 pq + q 2 = 1. Using the genotype frequencies shown in Table , if p = 0.4, what is the frequency of the AA genotype?
::Hardy和Weinberg用数学来描述均衡人口(p = A的频率, q = a的频率, 所以p + q = 1):p2 + 2pq + q2 = 1. 使用表所示的基因型频率,如果p = 0.4,A的基因型的频率是多少?Genotype Genotype Frequency AA p 2 Aa 2 pq aa q 2
Summary
::摘要-
The Hardy-Weinberg theorem states that, if a population meets certain conditions, it will be in equilibrium.
::Hardy-Weinberg理论指出,如果一个人口符合某些条件,它将处于平衡状态。 -
In an equilibrium population, allele and genotype frequencies do not change over time.
::在均衡的人群中,所有频率和基因型频率不会随时间而变化。 -
The conditions that must be met are no mutation, no migration, very large population size, random mating, and no natural selection.
::必须满足的条件不是突变、没有移徙、人口规模很大、随意交配、没有自然选择。
Review
::回顾-
Describe a Hardy-Weinberg equilibrium population. What conditions must it meet to remain in equilibrium?
::描述Hardy-Weinberg均衡人口。它必须满足哪些条件才能保持平衡? -
Assume that a population is in Hardy-Weinberg equilibrium for a particular gene with two alleles,
A
and
a
. The frequency of
A
is
p
, and the frequency of
a
is
q
. Because these are the only two alleles for this gene,
p
+
q
= 1.0. If the frequency of homozygous recessive individuals (
aa
) is 0.04, what is the value of
q
? What is the value of
p
?
::假设人口处于Hardy-Weinberg均衡状态, 具有两个等同基因, A 和 a。 A 的频率是 p , a 的频率是 q 。 因为这两个是这个基因的唯一两个等同基因, p + q = 1. 0 。 如果同性休眠个体(aa) 的频率是 0.04, q 的值是什么? p 的值是什么? -
Use the values of
p
and
q
from question 2 to calculate the frequency of the heterozygote genotype (
Aa
).
::使用问题2中的 p和 q 值计算异体zygote 基因型(Aa)的频率。
-
What is the
Hardy-Weinberg theorem
