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Microso. × 120218- x Flora of × nod/assign/view.php?id-2441608 e bookmarks bar. Import bookmarks now... Alex Petsko TE KUNENGA KI PUREHUROA UNIVERSITY OF NEW ZEALAND 18 S2FS MTUI Assessments Essay 2 Essay 2 Q. In lecture we used the scenario of genetically diverging lineages as the backdrop for several topics. In your own words, discusspotential short-term and long-term outcomes of genetic divergence between lineages, including the evolutionary processes that determine the outcome Your essay should be concise and informative and between 600 and 900 words. Make sure to read appropriately but you do not need to include referencing. Write a draft then review it. Please be mindful of your grammar, punctuation, spelling, etc., these factor a great deal into readability and clarity of thought. Use this as a chance to ensure you understand the scientific ideas AND to practice effective writing Upload your essay (as WORD.doc, or .PDF) via the portal by the end of Friday, 14 September. Your work will automatically be submitted to Turnitin, so use your own words. Submission status Submission status Due date Time remaining No attempt Friday, 14 September 2018, 11:55 PM 4 days 4 hoursExplanation / Answer
Genetic divergence is a term used to denote the two species which are once related and are now separated due to the accumulation of the genetic differences in them. The effect of genetic divergence can be short term or long term depending on the type of genetic variation it has obtained . The genetic divergence is caused by the changes in the genetic material, DNA. The composition of alleles are changed drastically if there is a stronger genetic drift .The genetic divergence is higher and more pronounced in smaller and asexual populations like fungi. Mutations , recombination , transposons etc causes changes in the alleles, between organisms of one species which eventually develop into new species. In fungi , natural and artificial ecosystem cause genetic divergence .
In the theory of genetic divergence , there is a controversy exists whether changes in the DNA sequence and genetic divergence or selection causes organisms to evolve. Genetic sequence changes occurs due to mutations like changes in amino acid composition , substitution and deletion rates, frequency of recombination. It is studied that selection operates in such a manner which eventually forces molecular evolution leading to genetic diversity .
It is also important to note that in current scenario , genetic diversity is caused by anthropogenic effects . These effects leads to habitat fragmentation . Fragmentation leads to isolation of species and becomes more threatening to key species of a particular habitat . Fragmentation also leads to extinction of certain species due to restricted gene flow or mixing up of new genes in a particular habitat . As fragmentation leads to isolation of species , the two species under goes molecular evolution which eventually develops into new species.
Genetic divergence occur in the following way. First separation of organisms of one species, incompatibility between the genes , isolation in reproduction , gene flow hindrance and finally evolution of new species.
The genetic divergence can be due to geographical isolation or it can be adaptive for survival of the organism depending on the surrounding environment. Geographical isolation occurs when organisms of same species are separated by geographical barriers and gene flow between these two species is stopped. The distance between the to organism is proportionally equal to the chance of developing into new species. Over a period of time the organisms in different regions of same species develop into two different species. New gene flow, mutations in these organisms causes them to arise as new species. Genetic distance also leads to reproductive isolation .This leads to reproductive isolation of species . Pre and post mating effects also leads to isolation of species. This type of effect leads to long term effects..
Adaptive radiation is a type of genetic divergence which leads to accumulation of mutation in the organism due to the changes in the environmental conditions. This type of speciation takes long periods of time . Cladogenetic speciation is a type of speciation which is also called as punctuated equilibrium . This type of speciation occurs in short bursts. In contrast anagenetic speciation is the type of speciation which is formed due to founder effect and its long term accumulation of genetic differences. The difference between adaptive radiation and anagenetic speciation is adaptive radiation is rapid compared to anagenetic speciation which is very slow and takes very longer periods for speciation .
Short term effects are those effects caused by mutation . It is not actually short term. For e.g. if an organism is mutated once and survives in a particular environment and when it reaches a other environment it adapts itself to the new place by certain mutations. So here the earlier mutation , is short lived . E.g. for this type of organism is bacteria
These are some of the long term and short term effects of genetic divergence between lineages. Mostly all the genetically divergent species have long term effects and cannot be reversed.