Difficulty: Easy to Moderate | Primary Game: Creatures 1
Emmit Ter: My shocked expression worked, and I finally got us moving on a new genetics lesson! We last let Gene Gnome take charge with a lesson related to appearance genes, and we touched upon the idea of duplicate genes. Remember that many Creatures genes can be copied when two genomes are mixed together, so a Norn might end up with two of the same gene. We want to look at the answer to one particular question: What can duplicate genes do and what implications might they have in future generations? Jump in with me as we have a little fun with genetics!
Part I: Laying the Foundation for Analysis
There are many different genes that can be duplicated. To make matters simple, this discussion will look at what happens when a single gene is duplicated. To see the results of this experiment, I chose a gene that would be easy to graph in the Science Kit. This is the digestion gene in Creatures 1: It states that 1 unit of starch is converted into 2 units of glucose, and the reaction occurs pretty quickly. This one is easy to measure because it will only be triggered when a Norn eats, so there are no worries about external sources. If you want to experiment, this gene is numbered 142 and labeled “027 Digestion – Reaction”. Different genomes may change its number or label, though.
Time for a biochemical graph! Sometimes the gene makes sense as it is, but a visual helps to explain exactly what it does. The spikes in the blue line (starch) show when the Norn ate a piece of food. Notice how that starch quickly drops off as it gets converted into the green line (glucose). It continues to drop off as the reaction continues, and the half-life for starch also kicks in. But that’s for another discussion about how different genes interact! The important takeaways are to see how quickly starch is converted into glucose and how nothing happens with alcohol. The reasoning for its inclusion will become clear further on! So now we have the base values and chemical levels that we can use for comparison. This graph may look fairly familiar, since Norns using the standard genome will experience the same reaction.
Part II: Duplicating a Single Gene
The Creatures 1 Genetics Kit takes some getting used to, and there is a little bit of a process involved with copying a gene. Unfortunately, there is no actual copy and paste feature: A new gene must be created and edited with the correct parameters. This is pretty simple for a gene like this one, but things get very complicated for the half-life gene or brain lobe genes! Luckily, those are outside of the scope of this lesson. Just be prepared to learn as you go!
Without further ado, the digestion gene was duplicated. If you recall from the lesson related to experimenting with appearance genes, only one duplicated gene was used. This makes sense, since a Norn can’t exactly have two different appearances at the same time! What would happen with this gene? As you can see from this graph, it looks quite similar to the baseline pictured above. Ignore the fact that there is only one spike in starch: The test Norn was very stubborn! Although it isn’t drastically different, the rate at which the starch spike falls is actually more dramatic. The reason for this is because both copies of the digestion gene are working at the same time. It’s an interesting math problem that will be explored in just a moment. The bottom line is that the game engine is using them both. So how does the math work?
Emmi Ter: How rude of my twin to leave me out until now! Contrary to what he might say, I am not some accidental duplicate. We’re a good example of how this duplicated gene works: We carry identical genetic instructions, yet we’re treated as individuals. The original gene states that 1 unit of starch is converted into 2 units of glucose. Two genes means that it ultimately states that 2 units of starch are converted into 4 units of glucose, which gives us the same ratio. Why is there a difference in the graphs? Because each gene triggers simultaneously, and the reaction rates convert starch separately.
Emmit Ter: What my twin is trying to say is that the two genes happen at the same time, but aren’t actually combined. There are two reactions that take place, even though they’re identical. Kind of like how Emmi and I have two explanations going on at the same time, and mine is clearly better. Just think of 1 unit of starch going into one bucket to be converted, and another 1 unit of starch heading off into a separate bucket. The same ratio of starch is converted into glucose, but the subtle change in the total time comes from the fact that each bucket is going through the reactions at the same time, but not together.
Part III: Mutating a Duplicated Gene
We now know that all duplicated genes will be used. This might mean that a Norn could end up with many copies of the same gene over time. Yet there is also one other consideration: What if a duplicated gene becomes mutated? In essence, it becomes an entirely new gene. In this example, a duplicate gene was altered to state that 1 unit of starch is converted into 2 units of alcohol. Now it makes sense why that chemical was in all of the graphs! In this Norn, starch is converted into both glucose and alcohol. It may seem simple, yet there are many implications of this in future generations. A duplicated gene might not be as harmless as it sounds: Note how starch is used up quickly and does not linger in the Norn’s system as long as it does in the base example. It might even mutate further into a dangerous gene.
The good news is that getting a duplicate gene is a rather rare occurrence. Standard mutations, where something is changed in the gene itself, are far more common. Still, the possibility exists for some very interesting results when a duplicate gene enters the picture! This is probably something that will really only affect high generation populations, yet it has the potential to produce very unique genomes… Possibly good, and possibly fatal.
Part IV: The Endless Possibilities of Duplicate Genes
Emmit Ter: At the end of the day, the really neat thing about duplicate genes is the vastness of them. Through natural duplications and mutations, an entirely new kind of Norn can come about! There are enough unique things that can happen with normal genetic mutations, but think about what duplicate genes can do! One duplicate might get mutated, yet the original might still be in place… So a normally fatal mutation might end up being harmless, or do much less damage than expected. Duplicates also make genetic analysis all the more challenging, and that’s precisely why the genetics team is here!
Part V: Extended Learning
Experiment, experiment, and experiment some more! The best way to learn more about Creatures genetics is to study existing genomes and see what various changes can do. Try to find a Norn who has a duplicate gene: Does he or she differ in subtle or major ways? Some genes can not be duplicated, as this is set in the gene header information. Why might these genes be set up so that they can’t be duplicated? There are some genes that seem to be accidentally marked as duplicatable. Can you find some of these and maybe create a better genome?