Chimeras have become very important in science. There are two major examples which I describe in two seperate pages
- Mitochondria in animal cells
- Cloroplasts in plant cells
In both cases it seems that cells (microbes ?) have "taken in" other cells, which evolved seperately, but have become integral parts on the main cell.
Other work is being done to create human/animal chimeras, so that human organs can be grown to order and not be rejected by the sick persons body.
At the end of this page I write briefly about Epigenetics, which is another strange and unexpected variation on genetics
However, there is a long human history of Chimeras - Homer's brief description in the Iliad is the earliest surviving literary reference to the Chimera:
"a thing of immortal make, not human, lion-fronted and snake behind, a goat in the middle, and snorting out the breath of the terrible flame of bright fire" It lived in Lycia in Asia Minor, and the name “chimera” has ever since been used to describe all such compound creatures, such as the Sphinx (lion’s body and human head), the Makara/Capricorn (goat torso and crocodile rear and tail) or the Lamassu (winged bull of the Assyrians with human head). Some of these are thought to be keys to the ancient mysteries.
Back to chimeras in Science
In the past, authors have generally said that the larger cell enslaved the smaller, energy-producing cell, both in the case of mitochondria and cyanobacteria. The author of the paper on mitochondria is clear that this is untrue, and the picture is more complex, however the plant / cyanobacteria author straightforwardly says that the plant enslaved the bacteria.
What we would have expected from cells 2 million years ago (or even today !) would be that one cell would eat the other, as we assume there is a sort of “war” between bacteria, microbes and cells, and each cell has semi-permeable barriers to keep out “invaders” but to take in food and nutrients.
It seems to be a sort of union, in both cases. Maybe it began as a type of symbiosis (ants enslave some aphids, some orchids can only grow if a particular fungus is present), but these cells are internalised, and propagate together with one offspring.
It is difficult to put a spiritual gloss on it, as far as I know there is nothing about photosynthesis, the double helix of DNA or the role of mitochondria anywhere in the spiritual literature. However, one might imagine that there are only a certain number of templates for living creatures in the planetary locker – maybe mitochondria are not descended from small lozenge-shaped bacteria, but they have both evolved following the same original template. It is equally difficult to imagine how the mitochondria arose - there is no known bacteria “in the wild” that could have formed the first mitochondria, in the same way that there are no suitable candidates for the plant / cyanobacteria combination.
However we choose to describe it, it is a very unusual thing to have happened, especially since it happened twice !
MicroRNA and Epigenetics
There are several types of RNA, which is identical in composition to DNA, but only has a single strand rather than the double strand of DNA. (New Scientist, 13th April 2014)
In brief, it seems that some excess miRNA fragments in the sperm are passed to the embryo (the same may also apply to the miRNA in the egg). However, if the father had been stressed, for example by a mouse pup being separated from its mother, then this affects the miRNA, and the stress is also passed to the children and grandchildren (but not thereafter). When purified samples of the stressed miRNA were extracted and injected into normal mouse embryos, the mice born were stressed too, proving that this really was the mechanism.
So, it seems the first work has been done to demonstrate a mechanism of how environmental and social factors can be inherited by offspring.