Discuss how eukaryotic organisms came into existence - Coursework Example

The study of the origin of the eukaryotes is a dynamic branch of this science, and much research has taken place in order to try and explain the development of this unique and structurally and functionally distinct class of organisms (Bacterial phylogeny, 2006). There are many theories and models regarding this debate, and many of those models are conflicting in nature (Bacterial phylogeny, 2006). This paper purports to discuss the most commonly accepted and relevant models of the origin of eukaryotes, analyzing their strengths and weaknesses, and presenting a conclusion about the needs for future research into this field, and the specific parameters that should be aimed for in that future research.

Discussion/Body: Let us begin our discussion with an understanding of a eukaryotic organism. The eukaryotic organisms, as opposed to the prokaryotic cells, have originated rather recently in the history of evolution (Bacterial phylogeny, 2006). . is no structurally developed control center like the nucleus of the eukaryotes (White, 2006), and the organelles, if present, are simple and non-membranous (White, 2006). Such organisms had the capability of surviving in the harshest of environments, as was necessary in the early development of the world’s ecosystems (White, 2006).

They reproduced by simple binary fission (Bacterial phylogeny, 2006) and could metabolise with or without the availability of oxygen (White, 2006), using a variety of chemicals as substrates for metabolism. In contrast, the eukaryotes are defined by the presence of a well-defined nucleus, which is membrane bound (White, 2006). There are a variety of organelles, which are complex in nature and many are also membrane-bound (White, 2006); the division of labour is enhanced and made more efficient in the eukaryotes (White, 2006).

Such organisms are increasingly oxygen-dependent (White, 2006), and have a reduced capability to withstand extremes of environments, requiring a more stable environment around them (White, 2006). There is a general consensus of scientific opinion that the eukaryotes came into being by the ‘fusion’ (Rivera & Lake, 2004) or ‘association’ (Rivera & Lake, 2004) of different prokaryotic organisms (Rivera & Lake, 2004). Unfortunately, the consensus of opinion is limited till here. From this conjecture, several theories have arisen in an effort to best explain the behavior of eukaryotes, both genetically and phenotypically.

Two of the most common models are the ‘nucleus and mitochondria co-origin’ (Bacterial phylogeny, 2006) model and the ‘nucleus-first, mitochondria-later’ (Bacterial phylogeny, 2006) model. Let us study the co-origin model first. Scientists supporting the co-origin model claim that a fusion