What was once a fun snack time activity can now be highly educational. Science teachers have long used gummy bears in various colours to illustrate how genetics are passed down from parents to children.
But it wasn't until recently when the genetic gummy bear experiment went viral through the tweets of an NYU social neuroscience professor named Jay Van Bavel. If you didn't know, human individuals get half their genetic makeup from their father and the other half from their mother.
Jacinta Bowler recreated the gummy bear experiment. Here, you can see a yellow and red gummy bear couple produce a half-yellow and half-red child (Gummy Bear A), as a child receives 50% genetics from each parent.
Then, gummy bear A's genetics are crossed with a new individual (a green bear). The yellow and red gummy bear provides half the new genetics for this next child. This means that genetic recombination of their DNA has mixed up the chromosomes received from their parents. It also means that DNA inherited from both grandparents show up in their gummy bear grandchild.
However, certain DNA strands will no longer be represented in children, despite receiving DNA from one's mother and father, as they move down a family tree. DNA continues to recombine as it is passed along.
For this reason, someone with excellent genealogy skills might know that they had a single Spanish ancestor in the 16th century. However, this DNA may have been completely eliminated from the modern person's DNA over the years. As a result, their DNA test results would not suggest a Spanish ancestor.
With the use of Punnett Squares, one can determine the genetic possibilities for each gummy bear combination. These charts are a quick method to discover which traits – dominant or recessive – will appear in offspring.
The gummy bear genetics experiment will help you better understand the long-term passing of genetics. But, the use of a simple Punnett Square can tell why your parents both have brown eyes, but yours are blue.