Steps towards human.

[SkinWalker]

H. erectus existed from about 300,000 years ago to about 1.5 million years ago (from now on, I'll use shorter versions like 300 kya and 1.5 mya).

 

The similarities between H. erectus and H. sapiens is striking: they were bipedal, used tools, had small canine teeth, used campsites/home bases, and apparently had clan structure and perhaps marriage. However, their brain cases were only about 2/3 that of modern H. sapiens (around 900 - 1100 cc as opposed to 1400 cc). Also, the H. erectus still had the sagital crest along the center ridge of the skull for anchoring jaw muscles used in chewing.

 

H. erectus lies between modern H. sapiens and the australopithicines in the hominid evolutionary timeline. The latter includes Australopithicus robustus and A. boisei, both of around 1.25 to 2 mya.

 

There was another hominid between these two, and there is much to suggest an evlutionary link from this one, H. habilis, and H. erectus. Actually, H. habilis was a contemporary of A. robustus and A. boisei, living at around 1.5 to 2 mya on the evolutionary timeline.

 

------------------------------

 

I've waited a while before posting in this thread, and those of you that know I'm an anthropology major may have wondered why. The reason is that the subject of Human Evolution is one that can be complex but certainly lengthy to discuss.

 

Perhaps the only way to really get a grasp of the subject is to educate yourself, either formally through classes, or informally through literature. For the former, I would suggest seeking honors classes in the High School level and definately biology classes as well as Physical Anthropology classes at the college level, even if you aren't majoring in a science. For the latter method, I could reccomend many books, but perhaps a visit to a used book store to pick up a physical anthropology text book (probably to be had for less than $6) and definately The Selfish Gene by Richard Dawkins.

 

Many people would recomend Darwin's works, but I caution against it for several reasons: 1) He was a Victorian and wrote in victorian style; 2) Victorian mores are not compatible with contemporary mores and values and Darwin cannot be read by those that would judge the literary style and wording through the lens of modern morals; 3) so many advances have been made since Darwin began his work on the Beagle.

 

Having said that, I fully recomend Darwin after immersing in evolutionary study to gain a wonderful perspective of his work, life and insight.

 

I close this post, but will post more if the discussion continues, by saying that Biology as a subject cannot be fully appreciated without understanding evolution. Evolution is an on-going process that defines the current state of biological entities from plants to animals to bacteria and viruses.

[Kurgan]

The Creation stories in the Bible (and pretty much all of Genesis until we get to Abraham) is Myth.

 

I don't mean Myth as in a "lie" but in the more common definition of a non-literal sacred story.

 

That is, it has meaning for life and it teaches moral lessons and values, but it is not science, nor literal history.

 

For the first three or four centuries of the Christian Church, it was interpreted by Christian teachers and theologians symbolically, allegorically, etc (ie: as Myth) rather than as literal historical fact.

 

I would speculate that this was also the way that the Rabbinical tradition in this period also viewed it.

 

Granted, there were some interpretations of Genesis as literal, but these were not the primary interpretations, and certainly not the only ones as modern day fundamentalists would like you to believe. I find it hard to believe that these Christians, who were far closer in history to Jesus and the Apostles than we are now, would have gotten it wrong for all these centuries.

 

Why should we assume that the people in the 19th century (when this whole messy debate started off, correct me if I'm wrong) were so much smarter at interpreting the Bible than the people who lived through it and who wrote it down and would have been closest to the actual events?

 

The writer(s) of Genesis weren't liar(s). But realize they weren't even THERE when the story "happened." Some Christians believe that Moses wrote Genesis. I disagree, but let's not argue about who it was. Suffice to say even if it was Moses, we're talking 1500 BC. Well, you do the math. Even with a very young earth that's thousands of years after the fact.

 

Do you think it mattered to a pre-scientific society who's primary goal was survival (by having land and lots of children) and wanted to teach their children about their God who protected them about some oddball scientific theory that wouldn't be understood for millennia?

 

Sure, you could believe in young earth creationism if you wanted to, but now we have mountains of scientific evidence suggesting that this hypothesis is very very unlikely (ie: the earth is billions of years old, not merely thousands, and fossiles exist of countless extinct and ancient creatures).

 

Evolution is also a very misunderstood theory. Most scientists agree that it happens, but not all agree exactly HOW it happens. Darwin suggested it was by natural selection, that is the living things that were best suited to their environments (note: evolution is environmentally dependant, not based on "progress" or anything like that) are the most likely to reproduce, thus passing on their unique genetic traits to the next generation, while those less suited tend to die out and thus are removed from the environment.

 

Over millions of years, with environmental changes species also change.

 

 

We did not evolve from monkeys, or gorillas or chimps. This is a misunderstanding.

 

Rather, we humans evolved from a COMMON ANCESTOR with apes. That is why apes are still around. If we evolved from apes, then they wouldn't be around anymore, or they would be utterly isolated from us in some environment in which they had a great advantage or something like that.

 

Evolution is based on random mutations (again scientists say) so it's more of a spectrum or transition, rather than "steps."

 

You might found a fossil that resembles humans more than apes, and another one that resembles humans even more. But this doesn't mean you have an ape, a "half human-half ape" creature then suddenly a human. That's not how it works. We can't reproduce with apes, even though our genes are very close.

 

One way a religious person who believes in God's creation of mankind might suggest a way these could be resolved is to say that evolution was "guided" by God to produce humanity. Or that God caused the mutations that favored the human race existing. Or simply that God began the creation (Big Bang) knowing full well (with foreknowledge) that humans would eventually result, and so he could reveal himself to them.

 

The Genesis story still has value, it is ultimately about SIN. It's about how the first humans were innocent, then they became curious. But they were also greedy and this greed caused them to fall away from their relationship with God, and they became alienated. This alienation lead to all sorts of problems in human society. They had to fend for themselvs and they fought one another. Their knowledge was imperfect and they didn't live in harmony with nature. But God still loved them and gave them help along the way like a parent dealing with rebellious children.

 

Christians see the Genesis story not as a depressing story about how God hates us, rather as the mistakes of our ancestors, that God tried to remedy by sending us his Prophets, and finally his own Son to redeem us from all those generations of sin and death.

 

This to me is far more important than trying to argue over and over like a broken record that scientists are all a bunch of atheist liars and the world is only a few thousand years old (thus shrinking down God's accomplishments, by saying that all these other creatures and history either didn't happen or it's some satanic trick.. I mean how did all those fossiles get there? It wasn't one flood, since they're spread out everywhere and in different layers), despite the evidence that continues to mount that evolution is more than just a "theory."

 

So does evolution happen? I say it does. The evidence points to it happening. Evolution isn't a religious belief, it's science.

 

That the Bible is inspired by God is a religious belief (based on faith, not scientific proofs), one which I share. But it does not force me to conclude that there is only one interpretation of it (ie: young earth creationism).

 

If believing in the literal creation story helps you to believe in God, fine. But I don't think that evolutionary theory is incompatible with Christianity, if the Bible is properly interpreted.

[Kurgan]

PS: This leads to the obvious question/retort about "well how do we know then what parts of the bible are Myth and which are true"?

 

Well again, I'd state that "Myth" doesn't mean lie. It simply means a non-literal sacred story that teaches a lesson.

 

We should look at how the early Christian Church viewed those documents definately, and we should also learn as much as we can about the cultural mileu and background in which each of the books was written. We should also look at the literary style.

 

Another example of a "Mythical" story is the Book of Job. The entire thing is an exercise in debating the idea "If God is Just, Why Does He Allow Bad Things to Happen to Good People?"

 

There may have been somebody like Job on which the story was based (people look at history all the time for "lessons" and heroes and villians to learn from, that's fine), but the point is, the story isn't meant to be taken as literal fact, but rather as a sacred story that is supposed to reveal to us truths about ourselves an about God.

 

Likewise, that Jesus and the Apostles said that these stories were "scripture" doesn't mean that they were literalists either. I'd again state that they saw allegory in them and treated them like Myth, not like scientific history.

 

Science is fun to study, but it doesn't tell us the WHY of things, only the how. Myths don't depend on science. They are multivalent stories that have meaning for each new generation. But if we ignore the context in which they were created we miss the point.

 

And finally, while the people comparing the Bible to science fiction I'm sure were trying to be clever about their non-belief statements, I would point out that the Bible was written before Science, so it can't be SCIENCE fiction. And Fiction is meant to be entertaining. While some of the stories in the Bible certainly contain entertainment value (who doesn't like to read about their heroes and their adventures?) it was written to record the history of a people (the Israelites/Jews and the Christians which came from them in the New Testament) and a teaching tool.

 

So these are sacred stories, just like the Epic of Gilgamesh, like the Illiad and the Odyssey, like Greek Myths. Even if one doesn't believe in the religion that created them, one can still appreciate them and respect the meanings inherent in them. That is why they are still studied today even by non-believers.

[SkinWalker]

Well said, my friend.

 

 

Hiroki, as human evolution is the complicated subject that it is, and since I could easily co-opt the entire thread with lecture upon lecture (the academic kind...), it might be easier if you or others direct the discussion through questions. Just don't start any with the word "why."

 

This is the kind of discussion I live for, but here's hoping it doesn't turn into a "evolution -v- creation" debate.

[toms]

can anyone explain the point of toenails? Especially little toenails...

 

I was looking at my foot (don't ask:D ) at the weekend, and realised my little toenail has been trimmed down to near enough non-existance. I can't see that toenails have had any evolutionary benefit since just after man started walking upright, so i would think that they would have disappeared by now.

 

----

There was an interesting looking programme on channel4 (uk) last week about human mutants (and the implications they have for our future evolution - very x-men:D ). Unfortunately i was at the pub and missed it. they have a page with interesting info though at http://www.channel4.com/science/microsites/S/science/body/bodyshock_mutants.html

 

Mentions ostrich footed people. cool. And also gives a list of some interesting looking books on the subject.

[Hiroki]

Toe nails, huh? I can't really say I'm sure, myself. Why do men have nipples?

[Kain]

Originally posted by Hiroki

Why do men have nipples?

 

Thats because every fetus starts out female and then the Y chromosome develops later.

 

Well, thats what I heard atleast.

[C'jais]

Originally posted by toms

can anyone explain the point of toenails? Especially little toenails...

 

I was looking at my foot (don't ask:D ) at the weekend, and realised my little toenail has been trimmed down to near enough non-existance. I can't see that toenails have had any evolutionary benefit since just after man started walking upright, so i would think that they would have disappeared by now.

 

Actually, many scientists think the little toe is tossing its towel in the ring pretty soon. We have no direct use for it, we can keep our balance just fine without it. As such, there's no selection pressure to keep it in place and we might just as well lose it.

 

Same with the hind claws on cats and dogs - these have once been an extra "toe" for the animal but have since evolved into this useless appendage. And I'll bet a lot that there are breeders somewhere out there already trying to breed them out (they're cut off in many cases as well).

[Kurgan]

Well the toenails, like the fingernails do serve a purpose, which is to protect the sensitive ends of the digits with a hard shell.

 

Think of the number of times we brush our stub our toes or fingers against things. Without the nails, we'd have a lot more cuts, scratches, etc.

 

Sure, its not invulnerable, but at least with a severe hit, the nail breaks, but the skin underneath is still intact in many cases.

 

So even if we don't use our toenails for scratching things anymore, they are still useful to have.

 

If we applied Darwin's methodology, then we'd have to ask whether or not people born without toenails would be more likely to survive and reproduce than those who were born with them. If so, then over millennia, the sans toenail people might become the "norm."

 

But, given medical science today, chances are these folks would be fitted with some kind of artificial replacement for the missing nails, if for no other reason than cosmetics.

 

I've heard all kinds of pseudo theories about applying darwinism to human culture, but it just doesn't work all that well (again, Darwin's theories are either incomplete or else they simply are too far reaching to apply to short periods of time like 100 years which to us is a super long time but nothing in terms of the environment). For example mate selection. Is it based on beauty? Well what is beauty? That can change within a couple of years, fashions come and go. People can alter their hair color, skin color, body shape, etc. Philosophies change, even economics change. Why do we today use pieces of plastic and paper to buy food instead of hunks of metal like our ancestors did? Etc. so in our ever changing culture, those kinds of things are in such a state of flux, it would be very hard to predict what is going to happen or to point out some group of people and say "they're becoming extinct." Heck, even people who can't find a mate, can visit a fertility clinic!

 

The other thing to consider with evolution is that it is a long and very slow process. In 10,000 years of human history, have we really changed that much? Not really.

 

Sure we're taller, but that's due to better diet. Sure we live a bit longer (the lucky ones) but that's due to improved sanitation and medical advancements.

 

And it's not as if (in some kind of social darwinist fantasy) that the "bad people" get "weeded out." Rather, we lift each other up through science and keep going.

 

Our brains are part of our genetic gifts after all, so using them to develop technology to help us survive and prosper as a species is not "defying nature" as I see it. Rather, we're doing what every other animal on this planet does, using our "tools" to keep ourselves from extinction.

 

Are we really smarter now than people 10,000 years ago? Again, I question whether we are. Most of the knowledge we have is not created by us, but was passed down and built on the work of others over generations. Take that all away and raise people in primitive conditions without education or technology and they wouldn't be much better off than our far distant ancestors.

 

Now we do have to be smart about it, or we could kill ourselves off. Just as a herd of deer could kill themselves off if they ran around and trampled and ate up all their food supply instead of only using what they needed.

[toms]

I guess that the thing with evolution is that Traits that are beneficial get multiplied, traits that are detrimental get dropped, but traits that are just pointless won't really get affected one way or the other.

 

It would be interesting to go into the future and see how (and if) humanity has evolved. Since (basically) we invented farming and began to take control of the environment around us Evolution has probably had less and less of an effect on us. If we have a weakness we tend to compensate for it artificially, so it is much less likely to get dropped from the gene pool.

 

I can think of very few areas (in the western world at least) where evolution would really still apply. Fashion and attractiveness have actually probably come to be a more important force on the gene pool than evolution. Disease immunity is about the only one i can think of. In fact, we could (theoretically) even start to de-evolve as we all no longer need fit muscles or good senses to survive in the world. Obesity is on the rise, that is for sure.

 

I guess there are harsher areas of the world where evolution would still be a factor... which could even lead to the intriguing possibility of a split in evolution. With 3rd world humans developing into much more impressive physical specimins, while we devolve into obese lumps in our hoverchairs with built in food and entertainment systems.

 

[edit] isn't the diversity of the human race (black, white, etc..) a sign of tiny evolutionary steps to suit their environment (ie, survival of the best suited...)

[Kurgan]

"Races" (ie: different skin colors, superficial facial features like the extra fold of skin on some asiatic mongoloid eyes, etc) have been around for a loooong loooong time (not sure how long but, suffice to say it's been a long time, before modern science, before nation states, etc).

 

Some theorize that "races" developed to deal with the climates and environments of groups of people secluded across the globe, perhaps after they were seperated by vast migrations after an ice age or other development (though that may not be true, because the "native americans" we think of today are thought ot have come from so-called "oriental" races in the east, and they don't "look all that different" in terms of racial characteristics, even after 15,000+ years, but then that's not much time in evolutionary terms).

 

The idea is that "black people" had darker skin to protect them from the sun in areas with less shelter from harmful rays, "white people" had lighter skin because they lived in cooler climates with more shade, etc.

 

But, the thing is, racial characteristics don't mean anything now (except our artificially constructed biases like racism, which came from slavery, tribalism, etc) because we have technology.

 

Examples:

Darker skinned people are at decreased risk for skin cancers, but have trouble getting natural vitamin D from the sun. Light skinned people have increased risk of skin cancer, but can absorb their D a little easier.

 

BUT, technology makes this irrelevant. Now dark skinned people can live anywhere they want (if they can get on a plane), and light skinned people can as well (again, if they can get on a plane). Light skinned people can wear hats, stay indoors and wear sunscreen. Darker skinned people can buy vitamin D tablets or eat/drink foods that have been fortified with these nutrients as a supplement.

 

And now that we're rapidly becoming a "global" community, interrmarriage increases, and there really are very few "pure races" anymore (and despite what some supremecists might say, the real "pure races" are like those isolated aboriginal tribes in various corners of the globe).

 

So it's not like all of a sudden "white" or "black" people are going to become extinct, technology makes everyone equal (or it has the potential to).

 

Then again, the terms "white" and "black" are arbitrary (since there are almost no "pure races" anymore), so in the future it may be that these races as we now call them cease to exist. Everybody will just be kind of "tan" or something, since we'll all be so stirred up it won't matter, unless people decide through some kind of "body design" (using advanced technology) to be a certain "color" or something sci-fi like that.

 

Racial supremecists usually fall into two categories (in my understanding). They either think in religious terms (ie: God created MY race first and liked it better, then he created the other races and didn't like them as much or made them inferior on purpose.) or pseudo scientific terms (ie: since evolution must be about PROGRESS, then the "dark races" existed first, and the "white race" is an evolutionary step above them, so the white race is superior).

 

The trouble with that idea is that 1) many many religions disagree with this idea and so it's one truth claim vs. another, but the supremecists are in the minority, and 2) evolution is NOT about "progress" as we think of it, but rather adaptation to an environment. If the "white race" was an evolutionary step up, then why do the "other races" still exist? And even if the "white race" was superior, who's to say it will be forever? Perhaps a NEW RACE will come out of the white race that will be superior to that (since evolution doesn't just magically stop, it continues)? Like people with green skin or something. See? Both arguments are concocted to say "my group, as I define it, is best" but doesn't stand up to logical testing and intense scrutiny.