Size matters—the more DNA the better

DNA
DNA double helix. Credit: public domain

A new study from researchers at Uppsala University shows that variation in genome size may be much more important than previously believed. It is clear that, at least sometimes, a large genome is a good genome.

'Our study shows that females with larger genome lay more eggs and males with larger genome fertilize more eggs', says research leader Göran Arnqvist, Professor of Animal Ecology at Uppsala University.

The study of seed beetles is published in the scientific journal Proceedings of the Royal Society B of London.

The amount of nuclear DNA per cell, or the size of the genome, varies by orders of magnitude across organisms. Our understanding of the evolutionary forces that are responsible for this variation is very limited. For unknown reasons, there are simple plants with a genome almost 50 times as large and grasshoppers with a genome 5 times as large as our own! In fact, the insects with the smallest and largest genomes differ by a factor of 200, yet they all look and act like typical insects.

Biological explanations for these dramatic differences come in two flavours:

The first suggests that variation in genome size is made up by "junk" DNA that has little bearing on organismal function and that random processes determine genome size.

The second instead suggests that the amount of DNA matters and that shapes genome size. The study of now present evidence suggesting that natural selection may be more important.

The study is published in the scientific journal Proceedings of the Royal Society of London. Their results show that variation in may be much more important than previously believed. It is clear that, at least sometimes, a large genome is a good genome.


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More information: "Genome size correlates with reproductive fitness in seed beetles." Proceedings of the Royal Society B of London. DOI: 10.1098/rspb.2015.1421
Provided by Uppsala University
Citation: Size matters—the more DNA the better (2015, September 14) retrieved 23 August 2019 from https://phys.org/news/2015-09-size-mattersthe-dna.html
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JVK
Sep 14, 2015
Our understanding of the evolutionary forces that are responsible for this variation is very limited.


Nutrient-dependent RNA-mediated protein folding biochemistry links everything known to serious scientists about biophysically constrained thermodynamic cycles of protein biosynthesis and degradation. The cycles link the innate immune system of all living genera to all biodiversity. The innate immune system protects organisms from virus-driven perturbed protein folding.

For comparison to what is known about ecological adaptation in the context of an atoms to ecosystems model of RNA-mediated cell type differentiation, claims that evolutionary forces are responsible for "variation" attest to the unexplained magic of neo-Darwinian nonsense.

Sep 14, 2015
@JVK

We all know you're driven by a belief that Genesis is a scientific text, the evidence otherwise be damned.

Drop the "neo-Darwinian", you despise everything about Darwin.

JVK
Sep 14, 2015
See also: The octopus genome and the evolution of cephalopod neural and morphological novelties http://dx.doi.org...ure14668

The size of the octopus genome links the light-induced de novo creation of nucleic acids from RNA-mediated events to cell type differentiation in all marine and terrestrial invertebrates to all vertebrates via the biophysically constrained chemistry of nutrient-dependent protein folding. The octopus genome sequencing showed the importance of considering microRNAs and adhesion proteins that link viruses and mutations to gene loss and to pathology.

All that can be placed into the context of links from quantum physics to quantum Darwinism, but not to the evolution of any species via mutations and natural selection.

Claims that I "...despise everything about Darwin" should be placed into the context of what I despise about neo-Darwinian pseudoscientific nonsense compared to Darwin's "conditions of life."

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