Understanding the history of the earth before the discovery of tectonicsre

While reading S.J. Gould's "Time's arrow, time's cycle  - Myth and metaphore in the Discovery of Geological Time", I noticed a few things.


In the first part of the book, Gould describes the ideas on the -brief- history of the earth as seen by Thomas Burnett (late 17th century). It gets far more interesting, as far as the modern thought is concerned, in the second part of the book. There, we find the work of James Hutton, a scottish geologist of the 18th century. He had made very accurate and original observations in his homeland (discordances, discontinuities...). He tried to explain them but in vain. How would it be possible to understand a discontinuity, sediment orientation, etc. without having any knowledge of a mechanism that would allow change of the surface of the earth? How is it possible to study and understand the history of the earth without using tectonics?


The third part of the book is dedicated to the work of Charles Lyell (19th century). There again, we see that he observes faults and other landscape results of earthquakes. As much as Lyell's work is significant to Geology, the mechanism responsible for some of his observations was still unknown; raising the same problems of the changes of the surface of the earth. All the theories preceding the discovery of tectonics were speculative even if the scientists tried to be realistic.


If we want to do a parallel with evolutionary biology, I remember the famous quote of Theodosius Dobzhansky: "Nothing makes sense in Biology except in the light of Evolution". Well, I think that something similar can be said about tectonics: "Nothing makes sense in Geology, except in the light of Tectonics". Therefore, Tectonics is to Geology what Evolution is to Biology.

Evolution by Alfred Russel Wallace

Yes, in our minds Evolution = Charles Darwin. But if we lived in the 19th century things would be slightly different.
In 1855 Alfred Russel Wallace had not only been convinced of the existence of natural selection but he strongly believed that it was a driving force in the process of evolution. Like most naturalists of his time, he traveled first in Brazil - on board of the Mischief - along with entomologist Henry Bates. What is really interesting about this naturalist is that he deliberately planned his work hoping to find evidence that would support the evolutionary theory, which by the way was called "the transmutation of species" at that time.
It does seem a bit odd that A. R. Wallace is largely unknown and it was very nice to see that a team of the Natural History Museum of London is currently working on his collections of insects and other specimens, as well as on his letters and notes.
Wallace had a bigger interest for studying populations and observing more insects and plants. Maybe this is due to his fellow friends with whom he collected all of his specimens, unlike Charles Darwin who traveled by himself. The fundamental ecological and biogeographical perspectives that Wallace gave to the evolutionary theory along with his observations that led to the "discovery" of natural selection make him a fundamentally important naturalist in evolutionary sciences and maybe another person for creationists to blame...

Evolutionary Epigenetism: why do we still mention it?

I was at the lab (UOA) looking for bibliography on the Pliocene of Greece, when  I found a copy of a rather old book on Evolutionary Paleontology ("Paléontologie Evolutive" of Jean Roger, 1976). It caught my attention, not only because it is one of my favorite subjects, but also because from what I've seen, Evolutionary Paleontology is and has been taught in different ways.

In the summary I found a lot of things that I've learned in relevant lectures, but there was one or two things that really got my attention. So here is my question: why do we still talk about evolutionary epigenetics?

Yes, in genetics classes we've learned that there are modifications of the genes after they're transcripted into mRNA, and we've been told that this is one epigenetic mechanism. But, what is the relation between this and the evolutionary theories of epigenetics?

The book enlightened one first point, in the chapter on the mechanisms of evolution there is one part about the epigenetic theory. The author quotes P.P. Grassié: "an evolutionary necessity is the acquisition of new genes". And later on we find another quote by S. Ohno (1970): "natural selection, much like a "policeman" is extremely conservative; if evolution depended only on this, from Bacteria could be obtained only many other forms of Bacteria. The creation of Metazoans, Fish, Mammals would be almost impossible without the creation of new genes." No further explanation by the author. This is epigenetic evolution. The lack of further knowledge on genetics, genes duplication, the fact that natural selection is able to produce new genes, horizontal transfer etc. generated this idea that there are other mechanisms that produce diversity, independent from Darwin's evolutionary theory. It does seem a little like an ensemble of speculations, because there is no specific proposition of a precise epigenetic mechanism. Also, and very wisely, the author does not take any sides, and waits for further research for an answer on the importance and the existance of such processes. 

Modern epigenetics do not have the same evolutionary dimension.