So, after an extended break, normal service is resuming, although the post today will be slightly off the usual topic of the evolutionary journey.
As I mentioned yesterday, I have been writing my bachelor project, and I thought I would share with you a little of the topic I have written it on.
I could write a post which would keep my good e-friend Argyle Sock very happy, with lots of statistical stuff in it, but, honestly, if I see the terms “not normally distributed” one more time, my head may go pop!
Also, the actual topic is much cooler than the stats (even though they are very cool too of course!).
I would like to introduce to a group of pigments called anthocyanins. These are the reason for the colour of blueberries, blackberries, some grape species, olives and many other fruits, and purple or red colourings in flowers, like these pansies:
The amazing bright red colours you see in autumn leaves is also down to anthocyanins.
So..why have I spent this last semester writing about pretty red colours?
Well..here is where it gets a little more interesting (not that pretty purple flowers are not interesting of course!)
Anthocyanins are also found in leaves which are not about to fall off the tree. Some plants have red leaves when they are young, and some plants can turn on and off the red colouring under certain conditions
Sciencey term for the day: This is called phenotypic plasticity….a phenotype is the appearance something has due to certain genes being expressed. If a phenotype is plastic, it means it can change under certain environmental conditions.
So, I have been looking at a particular plant, which is usually green and grows in shallow lakes. These lakes dry out a bit in the summer (Yes, we have summer in Denmark, sometimes!), and so some of these plants may end up out of the water. If this happens, 90% of these plants turn red, until the water covers them again.
The reason I have been looking at this plant (with a bunch of other people who are much better at scary maths than me!) is because it is not entirely clear exactly what the red stuff in the leaves does. In some plants it seems to act a bit like a sunscreen, in others it seems to stop the plant being eaten by insects.
The amazingly awesome Leaf-cutter ants (Several posts on them will come along a bit later in our evolution journey) will not harvest leaves which are red. This may be because insects do not see red the way we do, they do not have the parts in their eyes which can collect red light.
It has also been suggested that anthocyanins can help plants survive during cold or drought conditions, so, there seems to be a whole lot of stuff that this pigment helps with.
The health food industry has even been getting in on it, and you can buy anthocyanin supplements…this is because in plants, they work as anti-oxidants, and we are always hearing about how having free radicals is bad for us, and so we should eat blueberries, or whatever the cool food to eat this week is (its usually the most expensive one!). I am not entirely sold on this idea, as, last time I checked, I am not a plant.
So anyway, I have been working with an awesome group of my fellow students, and we have been trying to make these poor plants very stressed to see what happens. We grew them under some very bright lights, and then did some tests where we zapped them with..well…an even brighter light, to see what they did.
Personally, I find the plant we have been studying more interesting than the actual pigment we have been looking at, although, that has been fascinating to learn about. The plant itself has no stomata, which are the holes which plants use for taking in carbon dioxide and giving out oxygen and look like this in extreme close-up:
Because this plant has no stomata, it has to breathe through its roots, which is extremely cool! This means that it can only live in lakes which do not have a lot of nutrients in them, because, if you increase the amount of nutrients which end up at the bottom of a lake, you decrease the amount of carbon dioxide which is produced by the bacteria eating all the dead stuff at the bottom.
As more dead stuff ends up at the bottom of the lake, the bacteria down there start using up more oxygen than is available, and so the only ones that can live there produce methane (CH4) instead of carbon dioxide (CO2). This is what is found in my favourite land-types, the wetlands, bogs and moors.
Oh, yes, I forgot to show you a picture of the plant! This is the little thing I have spent 6 weeks growing, and then several weeks cutting up and zapping with bright lights!
So, I hope I did not bore you too much with the slightly off-topic post, and next time we will pick up on the evolutionary trail again, with some weird and wonderful creatures. If you prefer plants, hang in there, we will get to them in a few million years or so!