Extraction of Ancient Insect DNA from Copal!

 

This article discusses the ability to extract ancient DNA from insects trapped in copal. It tests the hypothesis of whether or not aDNA (ancient DNA) could possibly be preserved over such an extensive period of time. They were able to extract endogenous DNA molecules from one of the samples they analyzed, and able to make taxonomic identifications regarding the organism, though it was incredibly degraded. They did so via radiocarbon analysis. They discuss struggles regarding human DNA contamination, and how tedious the separation of modern human DNA from the aDNA was. Additionally, they discuss reasons behind why they advise against this type of analysis- it is highly destructive to the samples.

I am highly interested in the extraction, sequencing, and use of ancient DNA in modern studies. Therefore, it is not surprising that I find this article incredibly fascinating. Scientifically, I find this an incredible feat, which is primarily attributed to the fact that DNA degrades so quickly. It is absolutely insane to think that we may be able to extract ancient biomolecules, and harness the ability to not only make assumptions about ancient organisms, but also use the information gathered to make strides in modern genetic research. 

First Feathered Dinosaur Tail Found Preserved in Amber

In May 2015 a paleontologist, Lida Xing, found an amber sample presenting some very important information while digging in the amber mines of Mayamar. Inside the plastic amber case was a feathered tail of a dinosaur believed to have been preserved in there for 9.9 million years. Initial analysis of the tail showed that the tail does in fact belong to a dinosaur and not a bird based on the number of vertebrates present. The feathers were also very intriguing as they vary greatly from that of modern birds. The flight feathers that modern birds have are made up of a central shaft, called a rachis, which has smaller barbs jutting out from it, and then even smaller feather filaments, called barbules, coming out from those. The dinosaur feathers however don’t have a rachis, and instead are just made up of the barbs and barbules. This provides information on how feathers first began to develop, and also supports the conclusion that these first dinosaur feathers weren’t used for flight, but instead were most likely ornamental feathers used by the dinosaur to signal to one another.

The tail didn’t just simply provide information on the structural evolution of dinosaurs, scientists were also able to look at the chemistry of the tail’s surface. This revealed the presence of ferrous iron, a decomposition product of hemoglobin that was originally present in the dinosaur’s tissue.  Based on how well the ferrous iron was preserved, it is believed that further analysis will provide much more information about the chemistry of the tail, and possibly even the dinosaur's DNA. Finding well preserved samples of ancient organisms like this is very valuable, as they are not plentiful. The information that this sample has provided and will provide in the future could lead to some important discoveries that will give answers to some of the many questions currently held about dinosaurs.

http://www.nytimes.com/2016/12/08/science/dinosaur-feathers-amber.html?_r=0

http://news.nationalgeographic.com/2016/12/feathered-dinosaur-tail-amber-theropod-myanmar-burma-cretaceous/