Question

Почему в ходе естественного отбора не выбраковываются все вредные генные мутации

Answer 1

Потому что мутации это спонтанное явление, и к окружающей среде могут приспособиться только самые сильные особи.

Answer 2

Можешь перефразировать вопрос?
Я думаю, что в связи с тем, что мутации проявляются не всегда, однако, если носитель гена мутации дает потомство, то его потомство также будет носителем этого гена муатации и рано или поздно, но он активируется. Я думаю так

Answer 3

The Role of Natural Selection in Eliminating Harmful Genetic Mutations

Natural selection is a fundamental mechanism of evolution that plays a crucial role in shaping the genetic makeup of populations over time. It acts as a filter, favoring individuals with traits that increase their chances of survival and reproduction, while reducing the frequency of traits that are detrimental to an organism's fitness.

1. Variation and Mutation: Genetic variation arises from mutations, which are random changes in the DNA sequence of an organism's genome. Mutations can be beneficial, harmful, or have no significant effect on an organism's fitness. Harmful mutations are those that decrease an organism's chances of survival or reproduction.

2. Natural Selection: Natural selection acts on the variation present in a population. It favors individuals with traits that provide a survival or reproductive advantage in a given environment. These individuals are more likely to pass on their genes to the next generation, increasing the frequency of beneficial traits in the population over time.

3. Selection Pressures: Selection pressures are the environmental factors that influence the fitness of individuals. They can include predation, competition for resources, disease, and other factors that affect an organism's chances of survival and reproduction. Harmful mutations that reduce an organism's fitness are more likely to be selected against by these pressures.

4. Elimination of Harmful Mutations: In the process of natural selection, harmful mutations are gradually eliminated from a population over time. This occurs because individuals with harmful mutations are less likely to survive, reproduce, and pass on their genes to the next generation. As a result, the frequency of harmful mutations decreases in the population.

However, it is important to note that not all harmful mutations are immediately eliminated. The rate at which harmful mutations are removed from a population depends on several factors, including the strength of selection pressures, the frequency of the mutation, and the degree to which the mutation affects an organism's fitness.

5. Genetic Load: Despite the elimination of harmful mutations, populations still carry a certain level of genetic load, which refers to the presence of deleterious mutations in a population. This is because new mutations constantly arise, and some of them may be harmful. The genetic load represents the cumulative effect of these harmful mutations on the overall fitness of a population.

In conclusion, while natural selection plays a crucial role in eliminating harmful genetic mutations from populations over time, it does not guarantee the complete removal of all harmful mutations. The presence of a certain level of genetic load is a natural consequence of the ongoing process of mutation and selection in populations.