tgamble

Did you explain that evolution is only a theory?

MrDarwin

First you have to define "human", recognizing that the definition has both historical and biological components. It seemed pretty self-evident for many thousands of years, and has only been modified since the discovery of fossil humans and human-like creatures. The current working definition seems to be "member of the genus Homo" (i.e., Homo erectus, etc. would be considered "human"). So I think the underlying question is, "why is there only one living species in genus Homo"?

As hinted at by Morpho, part of the reason why there is only one species of human is that, by definition, scientists originally decided--before the discovery of hominid fossils--that humans were so different from all other creatures that we merited a genus and species all our own. (In fact, I seem to recall that humans were once placed in their own family separate from the great apes, although I'm not sure if that's still the case.) In other words, there is only one living species of human because biologists say there is only one living species of human--it's really rather circular.

So the better question is, why are humans and chimps classified in different genera, when we share so many physical characteristics and are so similar genetically? And the much stickier questions is, where do we draw the line between human and non-human in the fossil record?

Oolon Colluphid

AFAIK, the Hominidae have been united with the great apes, but depending on where you go, what the family is called varies -- are the apes in the Hominidae, or are we in with the Pongidae? It seems to this bystander that the people responsible for the names are scrabbling to catch up with our close kinship.

It’s sticky of course because ‘drawing a line’ is the wrong image, because evolution is a process. You cannot draw a line on a process without what’s on each side of the line being pretty much the same. Black can gradually shade into white without ever crossing some magic boundary. Despite one end of the process being clearly non-human and the other being human, it’s a process of becoming, so the line has to be arbitrary.

Oolon

[ April 15, 2002: Message edited by: Oolon Colluphid ]</p>

stonetools

This is a good question, because until 50, 000 years ago, there were two and possibly three species of genus Homo. There was Homo Sapiens in Africa, Homo Neanderthalis in Europe, and possibly Homo Erectus in Asia.
Around that time, Homo Sapiens expanded from Africa and the Middle East into central Asia, then branched out into Europe and Southeast Asia.
By 30,000 years ago, Homo Erectus? was gone from Asia. Two thousand years later, Neaderthals were finished in Europe after a 200,000 year run. Coincidence? I don't think so. I think good ol'Home Sap. may have had a little something to do with pushing our brother Homo species into extinction.
We're pretty good at the extinction business. Any doubts on that, read Farley Mowatt's Sea of Slaughter, where we are shown driving scores of other species to extinction or near extinction.We are also at the scene of quite a few extinctions of megafuana over the last 50,000years.
Check out Jared Diamond's "The Third Chimpanzee"
or THE NEANDERTHAL ENIGMA: Solving the Mystery of Modern Human Origins by James Shreeve. New York: William Morrow and Company, Inc for much detailed info on human origins.

DNAunion

DNAunion: Oh, you guys would have been so proud of the newest Star Trek series last night. On "Enterprise" they traveled to a planet that had two species of humanoids: one technlogically advanced and the other primitive and lacking in intelligence. The more advanced species was dieing at an ever increasing rate because the proteins that bind to their chromosomes were genetically defective, and the trend had been worsening over the past 2,000 years to the point of it now being an epedemic. On the other hand, the lesser species of humanoids did not suffer from this genetic abnormality and were actually showing signs of increased intelligence, though still a millenium behind the more advanced species. Dr. Flock found a cure, but he did not want to give it to the more advanced species. Why? He did not want to intefere with nature. He reasoned that the more advanced species would die off soon and that would open the door for the lesser species to flourish. Would it be right for him to deny the lesser species that possibility? Should he play God? Should they rewrite the future evolution was going to produce? What if a ETI civilization had landed on Earth and given an advantage to Neandertals and they wiped us out? Would that have been doing the right thing? The captain did not see things his way and said that it was doctors duty to help anyone he could, and that he especially should not stop from doing so based on theory. Dr. Flock replied that evolution is more than just a theory; it is an undergirding foundation of all of biology. Okay, which one of you guys wrote that script????

stonetools

How do you know an ETI civilization did not land and giveus an advantage?Also, remember 2001: A Space Odessey.Paleontologists are still scratching their heads over why we developed bipedality or why we first started developing our big brains( BTW, the last couple of threads are OT,so the original poster should disregard. Regardless of what the Trekkies say, Star Trek is NOT science

Principia

First point: Dr. Phlox actually said on the show: "Evolution is more than just a theory -- it is a fundamental scientific principle." Countless of other Trekkie websites have it listed this way.

Second point: for those people who criticized the (a)moral implications of evolution, the Prime Directive doctrine trumpeted by Roddenberry is truly paradoxical.

Third point: Trek is SciFi. But, this episode was one of those moments when the writers were courageous and insightful enough to predict the longevity of evolution as a scientific principle.

SC

[ April 15, 2002: Message edited by: Scientiae ]</p>

DNAunion

DNAunion: First point: I did not use quotes and was not claiming to be rewriting verbatim what was on a show I had watched the night before.

DNAunion: Appears thou art a Trekkie nerd?

DNAunion: Thanks for clearing that up for me: I was so confused.

DNAunion: Yet many if not most of their episodes have the being courageous and insightful enough to predict that we will find intelligent extraterrestrial civilization with warp-speed technology: just the kind that could have designed life and seeded it on Earth. I WIN!!!

Principia

*laugh*

Yes, no doubt, you win the contest for presenting the most incoherent and irrelevant arguments. Congratulations!

SC

EDIT: maybe you would like to sell to the writers your theory that the center of mass of the solar system oscillates as a result of planetary orbits? I am sure the material would make quite an entertaining piece of science fiction for all.



[ April 15, 2002: Message edited by: Scientiae ]</p>

DNAunion

DNAunion: Or maybe you would like to openly admit that you are being an asshole. No, wait....no need...your childish antangonism is already speaking for itself!