Purpose
The purpose of this study and corresponding results is to determine the kinship of a number of fish and shellfish. This must be done first to gain insight into the method, which is electrophoresis of proteins instead of nuclear material, but also partly to do some evolutionary considerations to ultimately come up with a family tree.
Theory
Map of evolution and genetics
If one considers the composition and diversity of animals on earth, from a Darwinian point of view, one is the view of all animals are created from the same ancestor, which here would be a little procaryote organisms. This organism would have to have multiplied to a lot of new species, which in turn would have evolved into new species and subspecies. The reason that so today is so rich in wildlife with birds, fish and land animals is that all these individuals have been selection pressure for different make from his companions so that they were better able to exploit a specific niche. As an example of this, we giraffe, Giraffa camelopardalis, the liver primarily from the leaves of the tall acacia, which nobody else can reach. It originates from Okapi which then has been a selection pressure to isolate themselves, niche differentiation, the Okapi, so that it could reach the high leaves, and you have looked at the way for a long period of time, creating two species. This example of the giraffe must not be viewed as Jean Baptist Lamarc did it with that through giraffe's life, it will have longer necks, but the emergence of spontaneous mutations that make it a longer neck, and that his offspring will have better survival prospects as a result of more food, causing gene / property with them.
Looking at this from a molecular viewpoint, one can use it to study their origin, one can look at what proteins different individuals have, and then among other things find out how old the protein is and what animals are in family with whom. This whole branch of biology, so the doctrine of heredity, or genetics is thus the study of living organisms originate their development and inherited properties through the study of genes. In other words, the importance of inheritance and variation when an organism created and developed. And it was primarily originated when people began to be interested in, from which human strains.
Analog and homologous development
When they began to classify animals on earth, in an attempt to create a universal family tree, one would need to know which animals were in families with whom, and how close the family they were, so it looked on their similarities. And you looked at the similarities among animals from two different criteria: homologous, which is a manifestation that they have the same ancestor, and then a common heritage. So is a property similar in two animals, because their common ancestor had the property. Analog is the opposite, here looks the same, not because they have the same basic form, but because the evolutionary process has developed the same characteristics, this type of development is also called convergent development. Another disadvantage of this type of development is called divergent development, and is an expression of two animals that are homologous in the same class (same basic form) but are different because they have evolved in two different directions.
Species protein composition
The exciting thing about species protein composition is that from this, can see from where they originated, one can also quite accurately dating the protein age, because if two animals, such as fish, have the same protein, so it is the same protein, understood such that the two proteins in principle could arise from mutations independently, but the likelihood of this is very close to zero. So if you find the same protein in two species, one can say with certainty that they have the same ancestor, but only on the comparison of proteins, one can not necessarily say anything more about when they have evolved away from their common progenitor. For example, we have in the experiment included an actin-myosin protein solution, and exciting about this is that it is one of the key muscle proteins by human muscle tissue is constructed. Has the fish this too, one can say a lot about protein age, for it is as I said, really long time ago that the human stem form, and fish, did differ from one another.
Something else that proteins course also shows the composition of DNA, since it is DNA which ultimately codes for the proteins a given cell can produce.
Method
see Exercise Guide.
The seafood we used for our experiments were as follows:
1st Shrimp (saltwater) - Prawn
2nd Edible crab - Cancer pagurus
3rd Cod - Gadus morhua
4th Pollock - Pollachius virens
5th Herring - Glupea harengus
6th Weevers - Trachinidae
7th Halibut - Reinhardtius hippoglossoides
8th Plaice - Pleuronectes platessa
Hypothesis
Before you had access to advanced molecular biology tools we have today made the stem of trees from other criteria. It looked primarily at appearance and habitat, I also thought, as a hypothesis to create a family tree based on these criteria, then later to see how accurate it is compared with the molecular biological method.
To provide a fairly realistic family tree, we need to explore different living conditions for the various fish and shellfish. The first thing we see is that they are all saltwater fish, this is not so significant compared with muscle proteins, but helps to understand their origins. One could thus imagine that even in ancient times, has been a split between the fish living in freshwater, and those who lived in salt water.
Secondly, we can see that they all have gills, this is obviously also a characteristic that is unique to just fish and shellfish, a simple observation, but it shows that they all have the same ancestor, but again far back. But that's just not all marine animals which have gills, such as turtles, saltwater crocodiles, whales and seals.
Results
Below is a scan of the gel, as it looked after electrophoresis. We had two pictures to choose from, this was the strongest pure color regularly, and I chose it for exactly this reason. For the second gel were tapes very weak, and it was therefore difficult to distinguish between the various individual bands. I think we can improve on this.
Wells contain the following:
1: Kaleidoscope standard 2: myosin-actin standard 30-10: fish (see method for sequence).
You can order now determine a protein approximated from this model (Fig. 5).. If you know its weight, one can see how much it should have horizontal and vice versa, one can find its weight by looking at migration. This we can use to find out which proteins in the fish (see liste1).
A protein that only shrimp and taskekrappen have seen as the band has been running about 8 mm, thus 5 kD, this corresponds to thymosin. Shrimp and taskekrappen thus both the protein, which in turn by the other fish have, this gives rise to a common ancestor that has evolved away from the fish. A band that almost all fish and shellfish have and which is horizontally about 4.6 mm can be nebulin. It is that they all have a band at this point, talks about protein here must be very old because it has been present in the different species now common ancestor, the protein is also working in collaboration with actin, as I will later show that they all have, so therefore, you have one, it was often the second, otherwise protein (in this case actin) does not function optimally if it is because the head would work. One of the first to get noticed, is that they all have a tape which has horizontal 4 mm, this is according to our model of myosin. This is like an old actin protein as it occurs in all species. Something else which is also unique in myosin-actin formation in all the fish is that it is they are the same muscle proteins, as we humans and most animals possess. This tells us that is, it is an incredibly ancient protein of ours, birds and fish common ancestor have had it, and this ancestor is many millions of years ago. This also says something about the protein status. They have been very essential and important for the animals, and not only that, they have also apparently functioned optimally in as many years, because had it not what would a second, more muscle protein have replaced it reasonably quickly, and with the second, more protein would have a better chance of survival. The protein actin, which is also a very essential protein, we find a little farther down, at about 5.3 mm. However, it is a bit unclear to see how many people have this protein, but ummidelbart I would think that it was most. The two proteins work together namely, one can not function without the other and vice versa.
If we now go in and look at what fish are in families with each other, we then quickly the cod and Pollock are very similar not only in appearance, but especially in protein composition, but also herring, many homologous bands with the two. That is why, from this view, safe to say that the plaice and cod are family and that they have a homologue development, herring, however, has evolved into a second recess, and through selective pressure and mutation, the so and say changed direction compared to the cod and Pollock.
Halibut and plaice is also evident from the protein composition to be in the family, and thus a homologue development, they still resemble each other much. However, one can say that rock disc is an earlier species, because its eyes more like a "regular" fish that have eyes on both sides, whereas flounder has both eyes on the same page. No mug turns out to also be the family of the two because they have very similar bands. One can however look at my previous family tree that I have placed them in the same species group, but it's also made from a purely appearance viewpoint. No face has changed considerably since torn between it and plaice. This phenomenon that a fish does not resemble anything from nature it really belongs, but that it rather resembles a second group is called a polyfyletisk group (say it as it looks like it belongs to). Shrimp and taskekrappen is looking very different, but they have some homologous bands, as none of the others. (See opg 2).
Discussion
There was only one real source of error, but this was also of much importance. Namely that our electrophoresis were not allowed to run long enough. This means that bands should not have walked so far and that therefore there is so much to spread. The spread between the tapes would otherwise have done two task considerably easier. It is therefore difficult to determine which fish have the proteins. Ribbon density has also affected the determination of kinship among the fish. However, it is also important to state here that although the two bands have walked the same length, it is not necessarily the same protein. For proteins composed as said by various amino acids and composition of molecules differ, and hence also their weight. So you can say well have two different proteins with the same molecular weight. The method to determine slægsskab I think ummidelbart, with my limited knowledge of other methods are fine enough, if so just experiment is well made.
