Papers from the past week. [OA] are open access. Feel free to request a detailed discussion on any of these.
General Interest, Important:
Vivisection, the practice of dissecting living organisms for scientific study, is nowadays mostly frowned upon for bioethical reasons. We can study anatomy when the animal is dead, and there are many technologies available to allow us to non-invasively study physiological systems, so there is no major reason to do vivisections anymore. These technologies haven’t always been here though, and a lot of the early biological sciences were filled with accounts of vivisections, which did bring about a wealth of knowledge, so they weren’t wasted (or for fun, as animal rights terrorists would have you believe). This special issue has several papers on the growth of vivisections during the early times of this period, the 16th and 17th century.
There are two interesting and important aspects to this paper. The first is the insights into the endosymbiosis that led to the eukaryotes. The second is the one I am more interested in, and that’s the power of phylogenetic networks over phylogenetic trees. We have many phylogenetic trees of eukaryotes, but it was only with this paper and their employment of a network that we could clearly see the presence of the endosymbiosis, since a tree can only show one set of relationships – detecting things like endosymbioses and organismal fusions is simply beyond the scope of a phylogenetic tree, since a tree portrays hierarchical relationships where genes are passed vertically from parent to offspring, whereas an endosymbiosis is a relationship where genes are passed horizontally between unrelated organisms. Networks have no problem with such things, and can portray hybridisations, endosymbioses, reticulations, and other such phenomena that don’t fit into the standard basal-to-derived branching scheme of a phylogenetic tree. This paper is an example of this.
It’s well-accepted that science needs to play a dominant role when deciding how to deal with issues such as climate, not only because meteorology is a scientific discipline, but also because the scientific method has built-in mechanisms to check up on the effect of such policies and modify them as needed. Case in point: this paper, which examines how current climate policies are faring in the overall picture, if they are really working towards keeping the damage to a minimum or whether they’re just useless. We will not see the results of our work until at least the 2030s, according to the paper, and the conclusion is a rather obvious “the sooner the policies get to work, the better”, since a constant result is that the sooner emissions peak, the fewer the damages will be in the long run.
- From incipient to substantial: evolution of placentotrophy in a phylum of aquatic colonial invertebrates. [OA]
I recently wrote a tiny bit on bryozoan placentas, so here’s a paper with much more information.
- The G4 Genome. [OA]
G-quadruplexex are structure formed at the end of telomeres. Telomeres are repetitive DNA sequences at the end of chromosomes that get eaten away through the cell’s lifespan, acting as decoys so that the useful chromosomal DNA doesn’t get damaged. When you have four of them next to each other, they will fold with each other and form the G-quadruplex (G4). The G4 acts to stabilise the telomeres, and so have been actively researched over the past few years because telomere degradation is heavily implicated in cancer and ageing. It was also recently found that G4 complexes are found in other regions of the DNA molecule, not just at the bookends of it. If any of this stuff sounds interesting, this paper has a great summary of it all, and it also delves into a pretty cool discussion of how the genome ought to be viewed as a complex landscape rather than just a string of ATGCs. This biochemical stuff isn’t my cup of tea, but it’s interesting stuff anyway. Read the rest of this entry »