A Genetic Oddity May Give Octopuses and Squids Their Smarts

According to a study from NY times, Coleoid cephalopods are the most intelligent invertebrates for their behavioral complexity through RNA editing. Coleoid cephalopods is a group compassing octopus, squids, and cuttlefish. Research has revealed that natural selection favored the RNA editing of the coleoids and slowed the DNA-based evolution that helped the organisms to have beneficial adaptations over time. The enzymes of these cephalopods swap out some of the letters (ACGU) of RNA encoding and produced modified RNA which creates proteins that weren't originally encoded in the DNA sequences. The coleoid genes share tens of thousands of these RNA editing sites which markably contained DNA mutations that leads to the source of new traits for adaptation of the organisms. Additionally, the RNA editing allows the invertebrates to swiftly manipulate their nervous system and to have dynamic control over proteins based on different environmental conditions or tasks. In octopus, RNA editing aids to quickly adapt to the changes in temperature.

I find it very interesting how the swapping of the RNA encoding letters in the coleoid genes creates DNA mutations which leads to advantageous traits for the organisms for adaptation. It is amazing how mutations in these invertebrates can be beneficial while in humans it can cause major defects.

Genetic Evidence Reveals Salmon are Shrinking!

      Salmon are an important species in the food chain and many species around the world rely on this fish as a part of their regular diet. There are a total of eight species of Salmon around the world, seven which are native to the Pacific Ocean and one which is located in the Atlantic Ocean. Each species plays a crucial role in maintaining a proper balance in the world's ecosystem, however, that role is being threatened by the fact that Salmon appear to be shrinking! Apparently researchers have been aware of this epidemic for some time now but what they didn't know was what was causing salmon to shrink. In order to find out why salmon are shrinking a study was conducted by the University of Helsinki and the Institute of Finland on a salmon population over the course of 36 years. A quote from a professor at Helsinki was posted by ScienceDaily stating that "we knew from our earlier research that the age at maturity had been decreasing over this period. Now we wanted to see if there were signs of this also at the genetic level" (Craig, 2018). This fortuitous observation provided scientists with a great opportunity to study a trait for adaptive evolution in vertebrates and apply what they learn to other species. The study was conducted by analyzing scales collected from salmon populations in the Treno River in Northern Finland. Upon analyzing the scales researchers found an allele located on a gene that influences maturity in salmon. The single locus responsible for late maturity in salmon was found in the Vgll3 region of the gene. According to the scientific journal posted in Nature, Ecology and Evolution researchers have calculated an 18% decrease in the vgll3 allele associated with late maturity in the salmon population. The gene which is passed on in sex specific selection is responsible for perpetuating this long observed trend in salmon during migration. Scientists are still exploring what evolutionary purpose this allele serves but what they do now know is it plays an incredible role in the trend of salmon populations around the world. By further studying the allelic effects of this gene, scientists may be able to glean more information about the fitness trait of evolution and get a better understanding of the phenotypic diversity of the salmon population as a whole.

The Pepper Moth: Decoded

The black peppered moth, a famous example of adaptive evolution, recently had a major breakthrough in what exactly helped it change form pepper to black.  Back in the 1800's, during England's industrial revolution, this moth adapted to its newfound, soot covered environment, by becoming darker, allowing it to blend in with the newly soot covered trees.  This adaptation allowed for the darker moths to pass down their genes, and become the new wild type.
Recently it was discovered that this change was all due to a gene called "cortex", which in most organisms codes for the function of cell division.  In moths, and butterflies, cortex was seen to code for wing and scale color.  This is not the beginning of this abnormality.  This gene is also known as a jumping gene, meaning that it can be found on different places all over the genome.  Dr. Saccheri, an evolutionary ecologist, describes it as "[a] huge chunk of DNA that doesn't itself code for anything, but somehow disrupts the nature of a gene".

The fact that these moths and butterflies of the like use a gene that normally codes for cell division in order to code for something as simple as wing color.  Also the fact that it is conveniently a jumping gene just adds to the strangeness of it's expression in the moth/butterfly.

http://www.nytimes.com/2016/06/02/science/moths-butterflies-dna-cortex-genes.html?rref=collection%2Fcolumn%2Ftrilobites 

http://www.nature.com/nature/journal/v534/n7605/full/nature17951.html