Failure to remove a flap rapidly can have important consequences in regions of repeated sequences such as deletion and duplication

TLS Online TPP Program

#Id: 8951

#Unit 11. Evolution and Behavior

TLS Online TPP Program

#Id: 8952

#Unit 11. Evolution and Behavior

One is unequal crossing over, in which recombination happens between different positions on chromosomes that are misaligned during meiosis. 

Another is replication slippage, in which the DNA polymerase loses its place and copies a segment of chromosome twice.

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#Id: 8953

#Unit 11. Evolution and Behavior

A third way that gene duplicates arise is by retrotransposition.

Here the messenger RNA from a gene is reverse-transcribed to DNA, which is then integrated into the genome.

TLS Online TPP Program

#Id: 8954

#Unit 11. Evolution and Behavior

As a chromosome with a new gene duplicate spreads through a population, there is polymorphism in the number of copies of the gene that individuals carry. This situation, called copy number variation.

TLS Online TPP Program

#Id: 8955

#Unit 11. Evolution and Behavior

TLS Online TPP Program

#Id: 8956

#Unit 11. Evolution and Behavior

Mixtures of exons duplicated from genes with different functions can generate new genes with new functions, a process that is called exon shuffling.