Natural Selection (i) It is a process in which heritable variations help survival of an organism, enabling it to reproduce and give rise to large number of offsprings. (ii)There may be change in the frequency of genes and alleles in the future generations. (iii)It leads to the formation of new species Hardy Weinberg law states that allelic frequencies in a population are stable and stay constant from generation to generation but natural selection allow only one allele to adapt.
Factors which affect Hardy-Weinberg equilibrium are (i) Gene migration Due to migration, new genes or alleles are added to the population and are lost from the old population in turn, changing the frequencies. Migration when happens multiple times, is termed as gene flow. (ii) Genetic drift Changes occurring in frequencies by chance is called genetic drift. Due to changes in allele frequency in new population, some different species are formed. This is called founder effect and the original population is called founder. (iii) Mutations These occur randomly and at very slow rates. They lead to new phenotypes and due to considerable genetic variation, speciation occurs. (iv) Recombination During gametogenesis, crossing over in meiosis leads to new combination of genes.
How does the process of natural selection affect Hardy-Weinberg equilibrium? Explain. List the other four factors that disturb the equilibrium.
Answers
Anand
Natural Selection
(i) It is a process in which heritable variations help survival of an organism, enabling it to reproduce and give rise to large number of offsprings.
(ii)There may be change in the frequency of genes and alleles in the future generations.
(iii)It leads to the formation of new species Hardy Weinberg law states that allelic frequencies in a population are stable and stay constant from generation to generation but natural selection allow only one allele to adapt.
Factors which affect Hardy-Weinberg equilibrium are
(i) Gene migration Due to migration, new genes or alleles are added to the population and are lost from the old population in turn, changing the frequencies. Migration when happens multiple times, is termed as gene flow.
(ii) Genetic drift Changes occurring in frequencies by chance is called genetic drift. Due to changes in allele frequency in new population, some different species are formed. This is called founder effect and the original population is called founder.
(iii) Mutations These occur randomly and at very slow rates. They lead to new phenotypes and due to considerable genetic variation, speciation occurs.
(iv) Recombination During gametogenesis, crossing over in meiosis leads to new combination of genes.