Examkin

Question

Difficulty: MediumModern Evolutionary Theory and Genetic Basis of Evolution

In a plant population growing in soil contaminated with heavy metals, a rare pre-existing gene mutation enables certain individuals to tolerate high toxicity. According to the modern synthetic theory of evolution, how does this trait become predominant in subsequent generations?

  1. Natural selection acts on the genetic variation, increasing the frequency of the favorable allele in the gene pool over time.Answer
  2. B
    The toxic environment causes non-tolerant plants to deliberately alter their somatic genes to pass tolerance to offspring.
  3. C
    Individual plants acquire metal resistance during their lifetime and directly transmit these physiological modifications to their seeds.
  4. D
    The mutation causes an immediate conversion of all continuous variations into non-heritable discontinuous variations.

Answer

Natural selection acts on the genetic variation, increasing the frequency of the favorable allele in the gene pool over time.
According to modern evolutionary theory (Neo-Darwinism), natural selection operates on pre-existing genetic variation produced by mutations. Individuals possessing the favorable allele survive heavy metal toxicity and reproduce more successfully, resulting in an increased allele frequency within the population's gene pool over time.

Step-by-Step Solution

1
Identify the source of variation in the population according to Neo-Darwinism.
The pre-existing gene mutation provides random, heritable genetic variation within the gene pool.
Modern evolutionary theory establishes gene mutation and recombination as the primary sources of genetic variation.
2
Evaluate the mechanism of evolutionary change acting on this variation.
Individuals carrying the resistant mutant allele have a higher survival and reproductive success rate in the presence of heavy metal stress.
Differential reproductive success (natural selection) favors advantageous phenotypes.
3
Determine the long-term impact on population genetics.
The frequency of the mutant allele increases in the gene pool over successive generations.
Evolution in the modern synthesis is defined as a change in allele frequencies within a population over time.

Key Concept

Modern Evolutionary Theory (Neo-Darwinism) and Population Genetics
Rate this question

Topics

Modern Evolutionary Theory and Genetic Basis of Evolution

More questions from this topic