The statistical method used to judge whether a population is genetically balanced in a certain trait is

The statistical method used to judge whether a population is genetically balanced in a certain trait is: the formula of genetic balance law.

The genotype frequency can be calculated by the law of genetic balance to judge whether a population is genetically balanced in a certain trait.

1. Formula of genetic balance law: A+a=p+q= 1, AA+Aa+aa=p2+2pq+q2= 1.

The following equation relationship exists between gene frequency and genotype frequency and remains unchanged: when there is only one pair of alleles (Aa), let the frequency of gene A be p and the frequency of gene A be q, then A+a=p+q= 1, AA+Aa+aa=p2+2pq+q2= 1.

In Aa and AA individuals, the frequencies of the two genes are certain, A=2/3, a= 1/3. After a generation of free mating, the offspring reached genetic balance, AA=4/9, Aa=4/9, aa= 1/9.

Second, the law of gene balance.

If a group meets the following conditions: the group is huge, and the mating among individuals in the group is random, that is to say, the mating opportunities of each individual in the group and other individuals in the group are equal, and there is no mutation, individual migration between groups or natural selection for gene exchange. Then, the gene frequency of this population, including genotype frequency, can be balanced.

Factors affecting genetic balance:

1. Non-random mating: These non-random mating methods will make some genes in the offspring appear frequently, and even cause rare homozygotes, which will affect the genetic balance;

2. Natural selection: individuals carrying a certain genotype may have more offspring than individuals carrying another gene, so that the frequency of a certain gene in the next generation will increase, thus affecting the genetic balance;

3. Gene mutation: DNA mutation will produce new alleles and pass them on to the next generation, thus affecting the genetic balance;

4. Gene exchange (migration) and genetic drift: When different populations are mixed, gene exchange between populations will gradually change the allele frequency, thus affecting the genetic balance.