Question

question 6 (multiple choice worth 3 points)
(05.03r mc)

years ago, scientists determined that all mitochondrial dna in humans came from a common african ancestor. based on this information, which of the following can be inferred?

• all modern humans evolved from one group of african h. sapiens.
• ancestors of h. sapiens all migrated from africa and evolved into different species.
• several populations of h. sapiens from different continents moved to africa.
• the mitochondrial dna of h. sapiens can evolve to form new species over millions of years.

Explanation:

Analyze the given premise

The premise states that all mitochondrial DNA (mtDNA) in modern humans traces back to a single common African ancestor. This concept is widely known in Hominid Evolution as "Mitochondrial Eve."

Evaluate the first option

Since mtDNA is inherited maternally, tracing all modern human mtDNA to a single African ancestor supports the "Out of Africa" model. This model infers that all modern humans descended from a single ancestral population of Homo sapiens in Africa.

Evaluate the second option

The second option suggests ancestors migrated and evolved into different species. However, modern humans (H. sapiens) are all one species, making this option incorrect.

Evaluate the third option

The third option suggests populations moved to Africa from other continents. This contradicts the genetic evidence showing an African origin and outward migration.

Evaluate the fourth option

The fourth option states mtDNA itself evolves to form new species. DNA molecules do not evolve into species; populations of organisms do.

Answer:

• (A) All modern humans evolved from one group of African H. sapiens. (Correct answer)
• (B) Ancestors of H. sapiens all migrated from Africa and evolved into different species.
• (C) Several populations of H. sapiens from different continents moved to Africa.
• (D) The mitochondrial DNA of H. sapiens can evolve to form new species over millions of years.