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Supergenes in evolution - Coggle Diagram
Supergenes in evolution
Introduction
Organisms must adapt to match their environment but when an organism has troubled doing this but continue to interbreed they are passing on those troubles to their offspring
Local adaptations, all organisms that are less fit compared to its enviornment will spread its genes in hand reducing recombination
Supergenes, a balance in an organisms polymorphis that is expressed by asimple genetic base.
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Background
First siting of the Punnett was in 1905 that shared the works of Mendel which shed a new light on Darwinism.
Punnett discovered that variation was the key to evolution when previously everyone thought it was natural selection
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Fisher explained that it was not from one mutation but many steps which was taken by a single locus but without recombination.
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Darlington and Mather coined the word super gene as genes acting on an allelic combination, this hypothesized that selection chooses unlinked loci over linked.
Mimicry
Supergene example which demonstrates similar physical characteristics in organisms with co adaptation and a stable polymorphism, most known example is the butterfly.
Heliconius Numata adapted by Mullerian mimicry which had a huge effect of reduced recombination and a large position of linkage disequilibrium due to wing patters and genome comparisons.
Ancestors of the Heliconius species can be seen with the same pattern through predisposed locus proving this to be a supergene.
Supergene
mid - late 20th century selection was used to change the rate of recombination when in strong linkage disequilibrium. The rate would increase but the loci but already be linked to act upon
When linkage occrured with a supergene, a mutation was more likely to happen which was known as 'sieve'
The spread of inversion is dependent on the migration rate as well as the number of loci but is independent of the fitness on a set of alleles.
Final supergene definition states that a genetic organism which allows switching of phenotypes that also has multiple links will achieve stable polymorphism
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Social polymorphism
The term 'green beard' is used to prove that when you take an organism with altruistic behaviors and have them interact with an organism who is a carrier of an altruistic allele, the organism will adapt altruism.
'Green beard' hypothesis is resembled by the red fire ants, this organisms reproductive success is determined by an odorant attracting gene named "GP-9." This gene is the green bread gene. Due to tolerance, the homozygous dominant queens were killed. The recessive allele was favored in selection due to the greater success in forming colonies. Once separated there was evidence of large non-codon regions.
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Citation
Thompson MJ, Jiggins CD. 2014. Supergenes and their role in evolution. Heredity. 113(1):1–8. doi:10.1038/hdy.2014.20.