Anyone can use their imagination to make up pretend creatures. Kids do it all the time. They bring home a drawing from school to show you with pride, and you smile and say, “Tell me about your wonderful picture!” while having no idea what is depicted therein. Adults create fictional characters and creatures when they write, host RPGs or just doodle. Using your imagination is a fantastic way of creating something new. But consider instead using probability and genetics. You may end up with something that you couldn’t have imagined on your own.
My kids are studying biology for homeschool this year, and my daughter recently finished the section in her book on genetics and heredity. She learned the joy of basic probability and Punnett Squares. “They’re fun!” she says (she’s 9).
Punnett Squares are handy tools to use when crossing two things of the same species and seeing what the possibilities are for traits in the offspring. This can be done for flowers, plants, birds or even people.
One of the labs she did for this section had to do with creating a creature with a long list of traits, such as different feet, beaks, antennae and more. Each parent had one dominant (T) and one recessive gene (t), so when two parents mated (each one Tt), there would be a 25 % chance that the offspring would be TT, 50% Tt and 25% tt. The recessive gene only shows itself outwardly with a tt result, since the dominant gene overpowers the recessive one in Tt.
So, for the lab my daughter used a pre-made list of made-up genes, each one having traits labeled dominant or recessive. Then she flipped two coins (one side of each labeled T and the other labeled t), writing down the results for each gene, and ending up with a random creature. Then she had the fun of drawing the resulting creature. While my daughter only did this once, you could do this any number of times to create different offspring from these parents. Also, we could have instead created the list of genes and traits ourselves to create even more unusual creatures.
To recap, here’s how it would be done. Make a list of traits you want to control. Decide what the dominant and recessive version of this trait would be (something like brown eyes (T) and blue eyes (t), or curly hair (T) and straight hair (t)). Use the coins as used earlier. Flip the coins and write down the result for each gene. If the result is TT or Tt, the dominant trait will be observed in the creature. If the result is tt, the recessive trait will be observed. The recessive trait in Tt is hidden behind the dominant one. TT, Tt and tt are called the genotype of the trait, the code that’s in the genes that is passed on to offspring. The phenotype of the trait determines whether the offspring gets brown or blue eyes, or curly or straight hair. The phenotype is what you see.
Since most kids notice family resemblances, this can be a fun way to explain how traits are passed along to younger generations. In large or extended families, many combinations of traits can be observed.
Try it yourself or with your kids, and upload pictures of the resulting creatures (and/or your charts) to the GeekDad Flickr group! We’d love to see what you come up with.