Friday, July 11, 2014

Interesting Science Subjects

Supernova 1987-A
It is Friday, again, so I am sharing some links to various and sundry scientific subjects today.

Over the years the Dredd Blog System has featured posts on a variety of scientific subjects.

Typically I try to keep up with new subject matter as the new subject develops.

In the past few years, and in this the 21st Century, a virtual revolution is taking place in genetics and microbiology, including viruses.

And I do mean a revolution in understanding based on discoveries in and out of the labs.

Viruses

For example:
"The theory of evolution was first proposed based on visual observations of animals and plants. Then, in the latter half of the 19th century, the invention of the modern optical microscope helped scientists begin to systematically explore the vast world of previously invisible organisms, dubbed “microbes” by the late, great Louis Pasteur, and led to a rethinking of the classification of living things.

In the mid-1970s, based on the analysis of the ribosomal genes of these organisms, Carl Woese and others proposed a classification that divided living organisms into three domains: eukaryotes, bacteria, and archaea ... Even though viruses were by that time visible using electron microscopes, they were left off the tree of life because they did not possess the ribosomal genes typically used in phylogenetic analyses. And viruses are still largely considered to be nonliving biomolecules —a characterization spurred, in part, by the work of 1946 Nobel laureate Wendell Meredith Stanley, who in 1935 succeeded in crystallizing the tobacco mosaic virus. Even after crystallization, the virus maintained its biological properties, such as its ability to infect cells, suggesting to Stanley that the virus could not be truly alive.
...
Now, with the advent of whole-genome sequencing, researchers are beginning to realize that most organisms are in fact chimeras containing genes from many different sources—eukaryotic, prokaryotic, and viral alike—leading us to rethink evolution, especially the extent of gene flow between the visible and microscopic worlds. Genomic analysis has, for example, suggested that eukaryotes are the result of ancient interactions between bacteria and archaea. In this context, viruses are becoming more widely recognized as shuttles of genetic material, with metagenomic studies suggesting that the billions of viruses on Earth harbor more genetic information than the rest of the living world combined.

Viruses may be little more than a ball of genetic material with a single functional goal of transmitting pure information in the form of DNA or RNA, but researchers are finding more and more evidence that viruses freely share their genes among diverse ecosystems, making viruses a powerful and large genetic reservoir that challenges how we think about all biological life.1 As pure biological language, however, viruses are inherently difficult to understand." - (Viruses Reconsidered).
...
"For more than 130 years, since the first inkling that viruses existed, these submicroscopic entities have continued to occupy a sort of netherworld in both the scientific community and the public consciousness.

What is clear, however, is phages’ vital role in human and environmental health, and many laboratories across the globe are looking to uncover how bacteriophages interact with their bacterial hosts to affect the Earth’s ecosystems. Found in virtually every biome on the planet, from coral reefs to the mucus layers of many animals, bacteriophages are the most ubiquitous “organisms” on Earth. We encounter billions of phages daily in what we breathe, eat, drink, and bathe in—shedding an equally large number as we live our lives. Phages powerfully affect genetic change in soils, vegetation, and oceans, regulating nutrient cycling, evolution, and even climate change on a global scale." - (Going Viral).
(emphasis added). If that doesn't generate some curiosity, let's review:
There are an estimated 1031 viruses on Earth. That is to say: there may be a hundred million times more viruses on Earth than there are stars in the universe. The majority of these viruses infect microbes, including bacteria, archaea, and microeukaryotes, all of which are vital players in the global fixation and cycling of key elements such as carbon, nitrogen, and phosphorus. These two facts combined—the sheer number of viruses and their intimate relationship with microbial life—suggest that viruses, too, play a critical role in the planet’s biosphere.
(Ocean of Viruses, emphasis added). You can look at the Series Posts tab and find a "series" posts (more than one post, linked together, covering a subject).

An example series is On The Origin of the Genes of Viruses (2, 3, 4, 5, 6, 7, 8, 9).

RNA World 2.0

A subject that is linked to viruses is the ongoing hypothesis about RNA, especially "RNA viruses."

One specific question is whether they were the first entities to replicate:
The ubiquity and diverse functionality of ribonucleic acid (RNA) in today’s world suggest that the information polymer could well have been the leading player early on in the establishment of life on Earth, and, in theory, it’s a logical basis for primitive life. One can readily imagine that RNA, as a catalytic molecule capable of serving as a template for its own replication, might have reproduced itself and grown exponentially in the primordial environment. Perhaps such an RNA-based proto–life-form even replicated with an appropriate level of fidelity to allow natural selection to begin directing its evolution.
(RNA World 2.0, emphasis added). That research goes on as more and more lab work is done wherein RNA pieces and parts are built synthetically, and as more and more small pictures fit together to begin to make a larger picture possible (Let There Be Life, The Scientist).

Cellular Shape Shifters

It was thought for a long time that once a cell type formed it would stay that type for the duration, however, new understanding is developing in this arena:
For many years, researchers believed that mature cell types, stable as they were, could not be changed into different types of cells. In recent years, however, the engineered overexpression of specific transcription factors has yielded many dramatic transformations previously not thought possible—including the regression of adult fibroblasts to stem cell–like states and the direct conversion of mature skin cells to neurons.

Some cells are now even known to switch type during normal development. The epithelial lining of the esophagus, for example, is formed as a columnar epithelium, like the rest of the gut tube. Only later does it transform into a stratified squamous epithelium resembling that of the skin. Pancreatic endocrine cells are also seen occasionally popping up in the bile ducts of the liver. This change occurs in late embryogenesis and involves a switch from a ductal to an endocrine cell type.
(A Twist of Fate, emphasis added). The list of new discoveries in the realm of Microbiology continues to fascinate year after year.

On Science & Religion

Polls show that substantial numbers of Americans do not believe Evolution, rather, they have or lean toward Creationist beliefs:
More than four in 10 Americans continue to believe that God created humans in their present form 10,000 years ago, a view that has changed little over the past three decades. Half of Americans believe humans evolved, with the majority of these saying God guided the evolutionary process. However, the percentage who say God was not involved is rising.
(Gallup). The further back in time we go alters the percentages, to the point that at one time, it was probably more ok that it is now for scientists to contemplate such matters:
It would not be difficult to come to an agreement as to what we understand by science. Science is the century-old endeavor to bring together by means of systematic thought the perceptible phenomena of this world into as thoroughgoing an association as possible. To put it boldly, it is the attempt at the posterior reconstruction of existence by the process of conceptualization. But when asking myself what religion is I cannot think of the answer so easily. And even after finding an answer which may satisfy me at this particular moment, I still remain convinced that I can never under any circumstances bring together, even to a slight extent, the thoughts of all those who have given this question serious consideration.

At first, then, instead of asking what religion is I should prefer to ask what characterizes the aspirations of a person who gives me the impression of being religious: a person who is religiously enlightened appears to me to be one who has, to the best of his ability, liberated himself from the fetters of his selfish desires and is preoccupied with thoughts, feelings, and aspirations to which he clings because of their superpersonalvalue. It seems to me that what is important is the force of this superpersonal content and the depth of the conviction concerning its overpowering meaningfulness, regardless of whether any attempt is made to unite this content with a divine Being, for otherwise it would not be possible to count Buddha and Spinoza as religious personalities. Accordingly, a religious person is devout in the sense that he has no doubt of the significance and loftiness of those superpersonal objects and goals which neither require nor are capable of rational foundation.
(Einstein on God, "Religion, and Science", 1941). The subjects where religion and science have comparable viewpoints also makes for interesting reading (Message of Science & Religion - Western).

Have a very good weekend whatever your persuasion.

Mykonos by Fleet Foxes (lyrics here):



1 comment:

  1. Wow. More viruses on Earth than there are stars.

    ReplyDelete