What is hard to understand is that life itself has only emerged once. Everything living is genetically related.
Just because two species are genetically related does not mean they will express the same traits. Example: jellyfish and ostrich
And yet all of the neural processes in the ostrich can be traced to jellies (Cnidaria) which were the first organisms to grow nerve cells. I guess it depends on how a person wants to define "traits". It may be sort of a cultural phenomenon (as in "culture wars") that we tend to think of traits in terms of gross appearance (no creationist wants to be told their ancestors were "dumb animals" despite the irony). But in a very liberal sense, there are certain traits that can be compared between any two creatures. The one I have been wondering about is the genetic similarity between humans and bananas. I'd like to know what those genes are doing inside of us! https://www.youtube.com/watch?v=nrbni0tVBZ8
Captain Kremmen: From your Post #2 Perhaps every place suitable for the emergence of life is already occupied by existing life forms & any new competitor becomes food before developing into a self sufficient organism.
Water is the main component of life in terms of number of molecules. The various potentials within water, most connected to hydrogen bonding, and their interaction with organics, creates a consistent set of potentials which cause life to follow paths that often converge. The organic carbon compounds have the ability to form endless variation allowing different "looks" at the same water potentials. If we start with water and lipids, with the lipids being a mixture of cis or trans bonding of molecules of various lengths, the push of water will still form a membrane since the "look" of the potentials is still close. Another good example is the DNA is the most hydrated molecule in the cell. Evolution from protein, to RNA to DNA follows the trend of increasing organic hydration all the way to DNA. Life will converge at DNA because this path was pre-defined by potentials that exist in the water. The water does not become more organic, so something had to give; DNA appears. If you look at the structures of life, by taking a snap shot of a cell, life lowers molecular entropy to form order from simple molecules, and gains energy value as its grow. For example, proteins fold in exact folds with a probability of 1.0. There is no entropy difference between two similar protein after they fold; these will converge at minimal entropy. However, since the universe prefers to increase entropy and lower energy, there will be universal push to reverse both the energy and the entropy within life; diversity and activity. With life and the universe, moving in opposite directions the path of life is useful because interaction of life with the environment and therefore the universe, causes an increase in entropy (also expends energy) providing entropic change in proportion to external potentials. Life becomes tailored to the unique set of potential within its local universe; first and second law.
You probably already knew this, but for those who didn't: http://www.omgfacts.com/Animals/You-share-50-of-your-genes-with-a-banana/50377 I can think of one trait I share with a banana, but decency forbids me from goin there..Please Register or Log in to view the hidden image!
There is evidence of microorganisms not related to the ones now on Earth, living back in the era when only microorganisms had evolved. They have not been studied enough to guess why they didn't survive and evolve.
Who knows what those genes are doing in us? I fully expect to see an explanation of this in the not-too-distant future. In retrospect I should have said I wonder what the genetic similarity is between humans and banana plants. It could be a coincidence I suppose, it just defies common sense that this is the case. Presumably this is related to protein and/or enzyme production. Interesting side note to get your mind off the bananas: there is a gene we carry which is related to the suppression of the white apricot homolog! Obviously there is a whole lot more to the picture here, but more to the point: we are 60% genetically similar to the fruit fly, so it's remarkable that this gene is associated with them as well. I keep wanting to Google on questions no one has the answer to. What does the suppression of the white apricot homolog have to do with evolutionary history, that it ever got into animal DNA, and it persisted thereafter? And what does it have to do with fruit flies (a homolog is a similar structure, which, although fruit flies must love apricots, we have no reason to believe there would be similar structures in the fly as in the plant). Curiouser and curiouser. We need a geneticist onboard at SciForums! I see Capt K is raising a point we sometimes see in science v creationism debates: Why did life only arise once? Actually there is no way to say how many times living organisms arose abiotically. It's just that there was a period of about 1-2 billion years when those first organisms (esp. cyanobacteria) appear to have dominated the Earth. This is evident from stromatolites (fossils of fiberous mats they build to form colonies). And during that time it's quite certain they rebuilt the atmosphere. In so doing they must have brought an end to the conditions under which abiogenesis could continue. But for all we know abiogenesis was widespread for some indefinite period of time, at least until the atmospheric chemistry changed too much, and/or the presence of feeders like cyanobacteria consumed the ingredients needed to promote abiogenesis.
