Dance Dance Evolution – do the DNA Dance!
What is this about?
In order for bacteria to grow and multiply, theirDNA must be replicated. Your task is to act as a DNA replicator and try to replicate a single strand of DNA by following the sequence of A/C/G/Ts that flash up on the screen. Mistakes made when replicating the DNA introduce changes (mutations) to the sequence. These mutations are how bacteria change (evolve) over time.
As you play, watch your DNA strand build and see how the four DNA bases pair with each other to form a double-helix. At the end of your turn your score will indicate the percentage of the sequence that you copied correctly.
How did you do?
High score – high fidelity replicator
Success! You are a high-fidelity replicator. This means you copied the DNA strand very accurately with a low error rate. This is essential as it ensures that the genetic information of the bacteria is carried from one generation to the next. It also prevents the introduction of mutations that could cause the bacteria to die.
Although not part of our game, DNA replication consists of mechanisms for proof-reading and error-correcting to even further ensure near perfect replication accuracy. So imagine you were able to go back and see the sequence you danced, you’d almost certainly be able to spot some mistakes and improve it!
Low score – hypermutator
Oh no! A low score means you are a hypermutator. This means you introduced a lot of mutations. Sometimes the proof-reading and error-correcting mechanisms fail and the mutations remain. This can be dangerous for the bacteria as it can introduce harmful mutations to genes which are essential to survive and affect their function.
However, DNA replication errors can actually be helpful in some circumstances, as they can produce mutations that enable the bacteria to quickly adapt to sudden threats to survival. So there is a trade-off between the positive and negative effects of being a hypermutator.
The Science of Dance Dance Evolution
Mutations are the raw information that we use to start to understand the differences between bacteria. We use mutations to tell apart closely related from distantly related bacteria; this is useful as it can help us to understand whether someone transmitted their bacterial infection to another person, or whether they both became infected from two different sources. This is important to know for example when patients become unwell with a bacterial infection on a hospital ward, as whether the bacteria infecting patients are closely or distantly related will have different implications for infection control.
We also use mutations to understand how bacteria become resistant to antibiotics. Sometimes bacteria can gain a whole gene that enables them to resist killing by an antibiotic. However often just a single mutation can prevent the antibiotic from working. By understanding which mutations are able to cause resistance, we can look for them in the DNA of bacteria causing infections. We can then predict which antibiotics will be able to kill the bacteria and treat patients with the right antibiotics more quickly than we can by using standard laboratory tests.
What is DNA, and how does it work?
Examples of how point mutations can lead to changes in an organism – dogs, humans and wolverine??
Different types of mutations summarised