
by
tuile » Mon May 21, 2001 1:07 am
Scientists (well, my proff for one!) do cite some examples of evolution:<BR><BR>Direct Evidence:<BR>Domestic breeds (artificial selection)<BR>Variation observed in the adaptation of a species that is introduced to a new area. The example was house sparrows that came form Europe. There was variation observed int their color (and wing length) as they adapted to new territories.<BR>Evolution of Insecticide Resistance. Insects evolved a resistence to DDT in three years. Three years!!! Amazing little bundle!!<BR><BR>Indirect evidence:<BR>Fossil record. The evolution of the horse is a fine example. <BR>Homologous structures. An example of this is the similarities in the forelimbs of frogs, lizards, birds, humans, rats, whales, bats. The plan of the forelimb is the same, with variation to allow different uses. Example of a common genetic code.<BR>Transfer RNA molecule. I don't have any notes about this one, except I think it was another example of a common genetic code. Help on this anyone????<BR><BR>For our class, evolution was simply defined as life changes which demonstrated descent with modification. Any changes induced by us would I think, be classified as artificial selection, as it is we or us who is imposing the restrictions and conditions for living, not the "natural" environment.<BR><BR>Evolution due to the natural environment can be seen in some degree in the high dwelling folk in the Himalayas and the Andes. I believe some studies have been done on their adaptations to their environment, but I don't know offhand what they were. I would think increased lung size???, increased capacity for the blood to carry oxegyn ( I can't remember the physiology !!)???? Faster transfer of carbon monoxide (crud, or is it dioxide??? I gotta go to bed!!!) and oxygen in the lungs???<BR><BR>As to the ape question, I think others have answered it great. We share a common ancestor with the apes; we did not evolve exactly FROM apes. The apes are doing great in their environment, provided we stop taking it from them and killing them, etc. etc. But there is still some amount of mutation occuring. <BR><BR>I don't think at all that we are the finished product of evolution. I think that is a form of arrogance on our part to assume that we're done! It's over folks! We're it! Look, but this is all from someone who's only taken one course in Evolution and Heredity and one course in Systematics. But,each course has led me to believe that we hardly know the tip of the iceberg. The process and mechanisms are soooo complex! Simply amazing. In fact, if you look at the absolute beauty in the harmony in a well-suited ecosystem and the amazing part each creature, plant, spore, and bacteria play a part, well for me, it makes me embarressed that we don't work with or within our environmnent better. But, that's just me! <img src="i/expressions/face-icon-small-smile.gif"border=0> We have no idea of what is to come, or how we'll handle it (genetically speaking!)<BR><BR>As to whether or not any changes will be induced by our own actions or nature's... at this stage, it seems kinda hard to distinguish between "our influences" and "natural selection" in a way. Our impact on the air, water and land... maybe as to genetic engeneering, weeelll, I don't like that subject. Makes me nervous. "You are meddeling with powers you can't possibly comprehend" -- the little university guy in Indiana Jones?? Something like that! I don't have a clue as to what we will have to respond to next. For me, my definition of evolution would not include anything we did for ourselves. It almost seems like cheating!!!<img src="i/expressions/face-icon-small-smile.gif"border=0> Like we have removed ourselves from the game and then claimed to have improved it, when we didn't understand it from the beginning. It seems to discredit the amazing acheivements of the snail (that shell!!) or the parasite ( that fecudity!!!) or the bat ( that hearing!!). I don't think fiddling with our own building blocks counts. Sorry, getting pooped, rambling!!!<img src="i/expressions/face-icon-small-smile.gif"border=0><BR><BR>Whassup with the paradox thingy? I'm not sure of the connection. Something simple I missed??? Why would there have to be a smallest thing? Is there a biggest thing? Perhaps it depends upon our definition of a particular thing? The way we reduce down, down, down,..am I arguing against myself in some strange fashion??? Lemme know, pleasse, <img src="i/expressions/face-icon-small-confused.gif"border=0> (I'll read this in the morning and smack myself on the head for not having seen the connection, huh? <img src="i/expressions/face-icon-small-smile.gif"border=0> ) bye..have a nice nite.<BR><BR><BR><BR>