Today we helped another lab member pick up some ethanol for a field trip. 100% ethanol is used for storing insect specimens, as it stops the DNA in the cells of the insect from breaking down. We need to keep the DNA in good condition so that we can extract it and sequence it, to eventually use it to determine how the different insect specimens are related to each other... but more on that later in the project! 

By using 100% ethanol and storing the insect specimens in the fridge, we can keep the DNA usable for years. Because older collections are often all pinned, or their specimens are in formalin (which makes the DNA unusable) or 70% ethanol (which contains water that breaks down the DNA), our project will need some fresh specimens stored in 100% ethanol to be able to do any work on the DNA. 

Today we learnt where to pick up ethanol from in the University, which will be handy when we go on our own field trip in Summer! 

Today we are thinking about how we are going to sequence the genes of our wasps. Originally, a taxonomist (a person who finds and describes new species) would use the morphological characteristics (what it looks like) of an animal to work out how it is related to other animals, and whether it is a new species or not. For example, a lion looks pretty different to a house cat, so by looking at them we might guess they are different species. We would also probably be able to say that they are more closely related to each other than either of them is to an elephant. 

Scientists represent this as a phylogeny - like a tree of life. 




With insects it can be a bit trickier. For one, they can be really tiny! They also sometimes show a lot of convergence - this is when two insects have a body part that looks the same, not because they are closely related, but because they both needed that body part to do the same job. You've probably noticed this in birds, bats and bees - they all have wings, but they're not closely related! They just all evolved wings so that they could fly. So if we were to group animals just based on whether they had wings or not, we wouldn't get a correct idea of their relationship to each other. 

These days insect taxonomists often use the help of molecular data as well as morphological. Inside every living thing is genetic information (like DNA or RNA) and by comparing how similar the DNA of a group of insects is, we get an idea of how many species there are and how they are related to each other. There is so much DNA in an insect though, that at the moment it is impractical to use all of it. So scientists working with molecular data tend to use just a few genes (genes = particular lengths of DNA. Jeans = cool denim pants).

Up until a few years ago, most people working on insects would use between three and six genes to build a phylogeny. A journal article (what's a journal article?) published last year used 1,478 genes to build a phylogeny of the insects. 1,478! That's a lot of genes!