| THEORIES WITH PROBLEMS - THE BIG BANG THEORY -> Evolution and adaption | Start A New Topic | Reply |
| Post Info | TOPIC: Evolution and adaption |
| Posted By: Keith Mayes Posted On: Oct 30, 2002 Views: 1090 | Evolution and adaption Hi Katie, Thanks for clearing up the age of the planet bit. To answer your question on evolution. Life first originated on earth some 3.8 billion years ago and has evolved into the many organisms we have today, us humans being just one example. At the same time, simpler organisms like algae, bacteria, yeast, and fungi, which arose several billion years ago, not only persist but thrive. The presence of single-celled organisms alongside complex organisms like humans testifies to the fact that evolution within a given lineage does not necessarily advance toward increasing complexity. When more complex organs are advantageous, complex organs have arisen. Single-celled organisms, however, fill many roles, or niches, much better than any multicellular organism could, and so they remain in a relatively stable state of adaptation. Adaption however, will still continue if we have major changes in the environment. You ask Where and what are the middle "stage" of the evolution process? Im afraid I do not understand the question so I cant answer it. Perhaps you can clarify. Thanks, Keith |
| Posted By: Katie Posted On: Oct 30, 2002 Views: 1088 | RE: Evolution and adaption Thank you for your response. My question :"Where and what are the middle "stage" of the evolution process?" To clarify what I meant was if we evolved from something (apes?) than why are there still apes and where is the middle stage of that evolutionary prosess? I don't know if I can clarify it anymore...sorry if you don't understand what I'm trying to say. |
| Posted By: Keith Mayes Posted On: Oct 31, 2002 Views: 1086 | RE: Evolution and adaption Hi Katie, Ok, Got it now. Our closest living relative is the chimpanzee, we share 98% of our DNA, and that's close. The fact that humans evolved from chimps into something that went on to become successful, does not mean that it was the end of the line for chimps, they are far better adapted to life in the jungle than we are, thats why they are still there. The evolution to humans would have started from the mating of just two chimps, not the entire population involved, and the resulting new born chimp would have had some small advantage, due to a 'mistake' in the genetic code. Maybe, because of this small genetic 'mistake' it could stand taller for instance and better see approaching danger on the ground. This genetic change would have been passed onto its offspring, and with this small advantage they would live longer and therefore breed more. In this manner the new chimps become successful, but different, from the other chimps and live a slightly different lifestyle because of the change that has occurred. They may for instance stay on the ground now and not live in the trees. We now have a new branch of chimps that lives on the ground, eats different food, is spending more time standing upright and is not in competition with the original chimps. They live side by side. The new chimps undergo changes by adaption to their new lifestyle, and gradually pursue their own line of development that eventually leads to human beings. There is no 'middle stage'. You cannot point to a moment in history and say this is the point of transition from ape to man. It was done over thousands of tiny changes, each overlapping the next, there is no famous 'missing link'. Try taking a bacteria and a man and asking the same question - what is the middle stage. See what I mean? Keith |
| Posted By: Katie Posted On: Nov 3, 2002 Views: 1076 | RE: Evolution and adaption Thank you. I'm now understanding what the heck it's all about. I still don't believe it, but I understand the theory. You are very informative. |
| Posted By: Nicho Posted On: Nov 27, 2002 Views: 1055 | RE: Evolution and adaption I know it's probably too late for the purposes of your discussion, but I just wanted to point out an inaccuracy in Keith's explanation of human evolution. It's a very subtle point; Keith was mostly correct in his explanation and very often the precise kind of evolution that Keith described actually does occur in nature. It's a common misconception that humans evolved from chimps; people tend to confuse "nearest living relative" with "ancestor." However, the fact that chimps and humans are so closely related points to a common ancestor for the two species, not an ancestor-descendant relationship. Chimps are very likely more similar to the common ancestor than humans (austrolopithicene remains suggest this; they looked almost like upright chimpanzees) but they actually represent a distinct evolutionary branch. The fossil record suggests that it's not uncommon for a single species to evolve in two directions at the same time. It could be that some species of arboreal ape was subjected to environmental stress in the form of shrinking forests. The ancestors of chimps may have adapted to the shrinking jungles by taking to the ground occasionally and the ancestors of humans may have wandered into the sevanna to make a go of it there. The point is, originally there was one species exchanging genetic information through unimpeded breeding and at some point the gene pool was divided by environmental barriers or mutation. One portion of the gene pool, through continued adaptation, evolved into chimpanzees, and the other into modern humans. Clear as mud right? I hope it helped anyway. |
| Posted By: Keith Mayes Posted On: Nov 27, 2002 Views: 1053 | RE: Evolution and adaption Hi Nicho, I always knew that someday somebody would make a monkey out of me :-) Many thanks for clearing that up, I have always found the small print of evolution confusing as text books on the subject tend to be a bit weighty. Thanks again, Keith |
| Posted By: Carl Rofe Posted On: Feb 4, 2003 Views: 1001 | RE: Evolution and adaption I watched a documentary on the find of the "Lucy" fossils. Fossil finds like that are found to be dated back to about 3.5 million years or so. If there existed a number of related species which had the attribute of similar "early" human form, as shown in the documentary, what would be the likely cause of such an extinct that only our kind remains? Was it luck or did we have an advantage? Bipedalism is theororised to be an attribute of all these similar species. |