Genetic Shuffling (Meiosis) — Definition & Overview

Genetic Recombination

Genetic shuffling, or genetic recombination, is the creation of new combinations of traits in offspring that are different from those in the parents. In eukaryotes, this happens as a result of sexual reproduction.

The two main processes that contribute to shuffling are meiosis and crossing-over. Genetic shuffling can also happen between prokaryotes, like bacteria, but it works differently since they reproduce asexually.

An Example of Genetic Shuffling:

For this blobby species, red body color (RR) is dominant to white body color (rr), and long arms (LL) are dominant to short arms (ll).

A red individual with short arms (genotype Rrll) mates with a white individual with long arms (genotype rrLl). They produce a child with a red body and long arms (genotype RrLl).

Now, suppose red body color and long arms are considered attractive traits. In this case, genetic shuffling resulted in an advantageous combination of genes.

However, shuffling of genes can also break up favorable combinations of traits.

For example, these two blobby individuals in the pedigree below, each have a favorable combination of traits—red body color and long arms, so it makes sense that they would be likely to mate with each other.

But there's also a chance that they could produce homozygous recessive offspring.

The takeaway message is that genetic shuffling is not necessarily a "good" or "bad" process but is simply something that happens during sexual reproduction.

What Is Genetic Shuffling?

Genetic shuffling causes an increase in genetic variation. One type of shuffling, crossing-over, happens in sexual reproduction during meiosis.

Let's refresh our memory—remember how homologous pairs are chromosomes that have the same shape, size, and carry the same type of genetic information? Also, recall that crossing-over is when the homologous chromosomes pair up and switch parts of the genetic information.

Genetic recombination is the result of this mixing; it is the random combination of both parents' genes. You can see an illustration of this below if you're a little fuzzy on it.

Humans have 23 pairs of chromosomes and during meiosis can recombine these into 8.4 million gene combinations. That's a lot of variation. This is how you get different features from both of your parents, like your mom's eyes and your dad's chin.

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$\color{#8925AE}{\text{Genetic Shuffling}}$ : The result of crossing-over, it is the random combination of both parents' genes during meiosis

What's Genetic Shuffling?

Genetic shuffling, such as genetic recombination, is a complex process which causes variation. Meiosis is the process by which diploid cells become haploid. More generally, this is how males produce sperm and females produce eggs.

Each chromosome has a "sister": one comes from the father, and the other comes from the mother. These two chromosomes line up and transfer a portion of the genetic information from one to the other. This process of transferring genetic information is called recombination.

The reason behind this is so that the offspring will have a unique portion of each of their four grandparents' genes. This also ensures that siblings are not all genetically identical.

(Video) Crossing Over and Recombination

by Learning Simply

This video goes into the details of how crossing-over occurs in meiosis and how this genetic recombination, or genetic shuffling, gives us biodiversity.