48. junk DNAjunk dna refers to dna that is thought to be a single or set of DNAsthat can cause biological variation or death in Dna. now scientists think it may be alien coding but also one of the most mysterious part of dna.introductionedit how do simple organisms such as yeast and worms evolve into complex organisms like birds and mammals a broad comparative study of genomes shows that the answer to a question may be hidden in the organisms junk dna american scientists found that the more complex the organism the more it carries the garbage dna but it is precisely these non-coding useless dna to help advanced organisms evolved a complex body.

There are many possible explanations for this so-called junk dna from mutation protection to the structural support of chromosomes. however the consistent study of junk dna from humans mice and rats shows that important regulatory mechanisms may be involved in this area to control underlying biochemical reactions and developmental processes which will help creatures evolve into more complex bodies. the fact that more genes in complex organisms do not mutate compared to simple eukaryotes undoubtedly greatly reinforces this finding. to gain a deeper understanding of this issue a research team led by david haussler a computational biologist at the university of california santa cruz ucsc evaluated five vertebrate-human mouse rat chicken and puffer were compared with the junk dna sequences of four insects two worms and seven yeasts. the researchers got an amazing pattern from the comparison: the more complex the organism the more important the junk dna seems to be. the implication here is that if different kinds of organisms have the same dna then the dna must be used to solve some of the key issues. subsequently the researchers compared vertebrates to insects which are more complex than worms and found that more than 66% of the common dna contained uncoded dna. adam siepel a ucsc computational biologist involved in the research said the study on worms needs to be treated with caution because scientists analyzed only two ofthe genomes.

nevertheless siepel believes that this finding strongly supports the theory that the increase in the biological complexityof vertebrates and insects is mainly due to the fine mode of gene regulation. philip green a molecular biologist at the university of washington in seattle agrees. the research is convincing he said but at the same time he emphasizes that the study of all non-biologically shared uncoded dna remains inconclusive