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Difficulty: EasyModern Evolutionary Theory and Genetic Basis of Evolution

According to modern evolutionary theory (Neo-Darwinism), which mechanism serves as the ultimate source of new genetic variations upon which natural selection acts?

  1. Gene mutations that alter DNA sequencesAnswer
  2. B
    Somatic adaptations acquired through use and disuse during an organism's lifetime
  3. C
    Non-heritable environmental modifications of continuous phenotypic traits
  4. D
    Functional adjustments made by analogous structures in response to habitat demands

Answer

Gene mutations that alter DNA sequences serve as the ultimate source of new genetic variations in Neo-Darwinism.
Modern evolutionary theory (Neo-Darwinism) establishes that random gene mutations (along with genetic recombination) generate new alleles. Natural selection then acts upon this heritable genetic variation.

Step-by-Step Solution

1
Identify the primary source of genetic variation in population genetics.
Gene mutations create brand-new alleles within the gene pool.
Modern evolutionary theory unites Darwinian natural selection with Mendelian genetics, establishing that mutations produce genetic novelty.
2
Distinguish heritable genetic changes from non-heritable modifications.
Only changes in germline DNA (gene mutations) are inherited by subsequent generations.
Acquired somatic traits or environmental phenotypic shifts do not alter germ cells.

Key Concept

Gene Mutation as the Source of Evolutionary Variation
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Topics

Modern Evolutionary Theory and Genetic Basis of Evolution

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