Part A
On Earth there are estimated to be around 30 million different organisms. With this sheer volume of different life and the natural human instinct to know as much as possible, it is necessary for us to break up the huge amount of information into more convenient groups. Scientists take two different approaches to this the first is the classical taxonomy, also known as the five kingdom system and the second is new taxonomy or the three domain system. The five kingdom system has developed with time. Living organisms were first grouped according to how they moved, with plants in one kingdom and animals in a second, by Aristotle during the 4th Century BC. In 1700s Linnaeus developed the system of naming organisms, which we still use today, called binomial nomenclature; this system
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The five kingdom system is more organised than the domain system. In the domain system the two types of bacteria are divided and then everything else in the world is lumped together in a third domain. In the kingdom system things are divided logically according to their cell structure and appearance into five (or six) neat and tidy groups.
The kingdom system is better for understanding past mutations of an organism, because often mutations are just a reaction to a sudden change in environment. For example penguins are birds but, because of the extreme climate they live in they find no need for flying and instead their wings developed into flippers for swimming.
The domain system is superior when it comes to predicting future mutations, because it is easier to see subtle changes in DNA structures than to wait for it to have a more significant impact on the visible characteristics of an organism or its cell structure and make speculations on the final form the mutation will
(n.d.). Phenotypic methods of classifying microorganisms describe the diversity of bacterial species by naming and grouping organisms based on similarities. The differences between Bacteria, Archaea and Eukaryotes are basic.
This era’s technology opened numerous doors for new types of communication and ways to retrieve an abundance of information. The Internet is clearly one of the greatest inventions of all time, allowing people to communicate across the globe and accumulate countless information in a matter of seconds. This phenomenon undoubtedly marked a significant progress in our society. However, it also gave rise to qu...
o The terms of the classification tell us what the individuals in that class have in common.
Carl Woese’s (1990) groundbreaking paper categorised the Tree of Life into three domains for the first time– Archaea, Eubacteria and Eukarya. Before this, Archaea were known as Archaebacteria due to their prokaryotic, single-celled appearance similar to bacteria. However, Woese analysed 16S ribosomal RNA from all three groups and discovered there were differences of such significance in the sequences, for example between positions 180 and 197, that Archaea should be classified as their own domain. The three domains are believed to have separated from one common ancestor, with Eubacteria and Archaea diverging 3.8 billion years ago and Archaea separating from Eukarya 2.8 billion years ago. This means that, despite their appearance, Archaea share more similarities with eukaryotes, such as 33 identical ribosomal proteins, than with bacteria.
The start of any evolutionary story told about us lies within the origin of the eukaryote cell. This remarkable event consisted of a revolution of cell type matched in momentousness by the arrival on the biological scene of the prokaryote (O’Malley). Bacteria had a couple billion years head start on eukaryotes and have given rise to many biochemical processes that are essential to the ecosystem (Wernergreen). One organism living within another defines endosymbiosis. Nobody can say the exact origin of the eukaryote cell. The endosymbiosis theory dates back to the earliest 20th century and devotion to different models of its origins is strong and adamant (O’Malley).
...ous amount of information into many biological processes, our phylogenetic relationships and evolution (NHGRI, 2011).
eLibrary. Web. The Web. The Web. 18 February 2014.
Bloom, B.S, Rehage Kenneth J., Anderson, Lorin W. (1994) Bloom’s taxonomy: A forty- year retrospective. Chicago:NSSE.
...he species of an animal, and diversity is having many different branching species. (Alexander 261)
They also describe microbes as organisms that are often too small to be seen without the aid of a microscope. Microbes, also known as microorganisms, can be broken down into four classifications that are bacteria, viruses, fungi, and protozoa.
As well as drawing on his own observations, Darwin drew from the work of Linnaeus, Cuvier, Hutton, Lyell, Malthus and Lamarck. In the hierarchial classificatory system of Linnaeus there is a tacit acknowledgement of relatedness, for example, species belonging to one genus have more in common with each other than they do with species belonging to another genus. Linnaeus was a creationist -- as evidenced by his egotistical proclamation "God crea...
Throughout time, of course, marine biologists have created methods—or “techniques” (163)—that allow such a task to become more straightforward. The method which mainly comes to mind involves close observation of the organism, and noting as much of its minor and major characteristics while attempting to identify it. By recording such details as the organism’s symmetry, general shape, colors, external appearance, internal structure, and measurement, marine scientists can refer back to identification guides to figure out what specific classification their organism fits in, or whether they have the right taxonomy in mind or not (Mertz, Garrison and Baker 163-164). Upon confirming the organism’s identity with the noted characteristics, finding extra information about it becomes much easier
Kasdorf, B. (2014). Welcome to the metadata millenium. Book Business, 17(1), 18-23. Retrieved from http://search.proquest.com/docview/1500945974?accountid=10043
It is easy to say that species are constantly changing, and branching off into totally new species. But how do we know where the species originate? Phylogenies help to show us how all kinds of species are related to each other, and why. These relationships are put into what can be called a cladogram, which links species to common ancestors, in turn showing where, when, how, and why these ancestors diverged to form new species. Without phylogenies, it would be extremely difficult to put species in specific categories or relate them to one another. Along with phylogenies can come conflict on which species should be related to one another. This conflict causes many hypotheses and experiments, which can lead to phylogenetic retrofitting, which means adding some kind of data to a phylogeny that was not originally included. In M. S. Y. Lee’s article “Turtle origins: insights from phylogenetic retrofitting and molecular scaffolds”, the origin of the turtle (Testudines) is very controversial, and has been the source of experimenting to try to prove whether it should be placed under anapsid-grade parareptiles, according to Bayesian analyses, or diapsids as sisters to living archosaurs. The use of experiments including molecular scaffolding, which is an experiment involving using the scaffold protein of the backbone to place the turtles in a certain taxa, is used to show where turtles should actually be placed. I find it very interesting that scientists continue to go back and forth between new and old phylogenies, constantly rearranging and questioning the placement. Phylogenies are not just important for showcasing where species originated from, but also to illustrate how DNA sequences evolve as well. For example, in class, we t...