Q3CC

Question

WHAT IF? There are three times as many Alu elements in the human genome as in the chimpanzee genome. How do you think these extra Alu elements arose in the human genome? Propose a role they might have played in the divergence of these two species.

Step-by-Step Solution

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Answer

In the human genome, Alu elements must have undergone more active transposition than in chimpanzees. Differential duplications may have grown more prevalent when the number of recombination errors in the human genome grew due to an increase in Alu elements.

1Alu elements

Primate species possess Alu elements, which are transposable elements (TE) or jumping genes. TEs move across the genome, or hop from one place to another, occasionally inserting copies of themselves directly into protein-coding genes.

2Genome

All genetic information about an organism is contained in its genome. Molecular sequences such as DNA and RNA are encoded in each cell of the body. The genome includes all the genes of an organism, including both coding and non-coding elements 

3Divergence

During the evolution of an organism, when two features develop out of a common ancestor that grew apart over time, the process is known as divergence. When a descendent species' population splits into two or more descendent species, its form and structure become progressively different.

 

The Alu elements are responsible for the divergence between the genomes of chimpanzees and humans, as they are more numerous in the human genome. Human impacts have also been linked to insertions or deletions of Alu in a number of situations.