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Week 4 involved exploring the role of Sexual Selection. In Week 5, we explore why animals look the way they do and how signals are used by animals to make decisions.


Setting up Spinder

Once again we’ll be logging into the eWorksheet using our Arludo ID – a student’s alias. When asked, please also ensure your students log into Spinder with their class code (at the top of their worksheet) and also enter their Arludo ID in the Player ID settings. This will allow you to track their performance and answers in your teacher dashboard.

In this game, students are trying to create peacock spiders with different traits. Individuals have their own spider on the top (seen above) and they have to make that spider look a a particular way. If the spider below theirs has the traits that they want, they swipe right and those traits are passed on to their spider. If they don’t want the traits that the bottom spider has, they swipe left and those traits are ignored.

It a really simple way for students to learn that traits are passed on to offspring, and to explore how different signals communicate information.

The game has several levels where students will build their knowledge and learn about why certain traits end up appearing together – because they are genetically correlated. That means that, in this game, it will be easier to create spiders with large, dark-blue tails and small, light-blue tails than it will be to create spiders with large tails that are light-blue (and vice versa). Additionally, it will be difficult for students to create spiders with large tails that are fast dancers.

As they play the game, they will learn about positively (large and dark tails) and negatively (large tails and slow dancers) correlated traits and why it’s impossible for certain trait combinations to go together. This is where you can talk about genetics and why plants and animals look the way they do.

The science data collected by the game will help students learn about how different signals can carry different types of information, and how certain signals may be better in certain contexts. More on that below.

How to read and use the figures

How the trait affects the time to swipe

If you take a look at the figure below, you can see that it takes students a different amount of time to swipe a spider epending on the trait students are asked to explore. Students are much faster at deciding whether a the tail is big enough compared to when they need to compare a tails colour or a spider’s dancing speed.

This is where you can ask students why they made decisions more quickly about certain traits than others. What does that mean for how our eyes and brains process information. Does this also explain why animals look the way they do?

How the trait affects the number of swipes

This next figure then explores how many swipes it took players to win that level.

As you can see below, they are really similar! So what this graph is telling us is that although it is easier to make decisions about whether a trait is the right size (above figure), it doesn’t mean that this trait is easier to create.

You can also discuss with students what affects how many times they swiped. This can be a discussion about sampling (i.e. maths) and how common different traits are in a population. By understanding that the bigger, darkest, and faster dancing individuals are rarer in a population, they can understand that it is difficult to make the biggest, darkest, and fast dancing spiders because they are hard to find. Even though they are easy to identify.

Even if your graph isn’t the same as the one below, you can still discuss the same story.

How trait combinations affect the time to swipe

This figure is similar to the first, except that instead of having single traits, it explores the creation of trait combinations – large size and dark colour, large tail size and increased dance speed, and large tail size and decreased dance speed. If you take a look a the figure below, you notice that anything with judging dance speed takes longer to do. This is because you have to make more decisions about whether the spider has the right traits.

The take-away message here is that id is sometimes more difficult to understand a signal, especially when it is complex. That’s why it’s important to be clear – especially for animals! Because imagine if you are trying to make a decision in nature, the longer it takes, the more likely you’ll encounter a predator – and that’s not a good thing!

How the combinations affect the numbers of swipes

This, once again, is similar to the second graph. Although it may look different, you can use it to teach the same lesson about what affects how many swipes you need to make. And that is the probability of finding the individuals with the traits that you need.

Extension questions

Some fun extension questions and projects for this game can revolve around finding animals and plants that have multiple traits and seeing which ones usually go together. Ask students to find some organisms they like and ask them to figure out which traits lead to individuals having more success. Are they the bright coloured ones? Are they the big ones?

This is also where you can introduce Gregor Mendel and his pea plants! You can start talking about genetics. and how this can explain why certain traits are more likely to appear together – because they are genetically linked. Or in other words, the genes appear to be very close together on a single chromosome.

Conclusion

This is a fun lesson where students can easily learn some basic concepts about genetics that are easily scaffolded into higher order concepts if teachers like.