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This is a response to Dr. Forbush's post about Outlawing historical documents from the fundamentalist viewpoint from a case in California. Stepdad's response to that and my subsequent comment resulted in a discussion on the Theory Of Evolution and "Inteliget Deisgn Theory. We got into it as a comment based item of discussion. I proposed that it be its own blog. It ended up as its own topic on Stepdad's blog. Since my response is too lengthy to add as a comment I have added it here. The original thread is here:
http://www.tblog.com/templates/index.php?bid=drforbush&" title="http://www.tblog.com/templates/index.php?bid=drforbush&" target="_blank"http://www.tblog.com/template...;static=352441
After my request that this become its own blog, stepdad posted this: &n bsp;
http://www.tblog.com/templates/index.php?bid=stepdad&" title="http://www.tblog.com/templates/index.php?bid=stepdad&" target="_blank"http://www.tblog.com/template...;static=353119
This is my reponse to that article:
Reply to: stepdad
So here it begins:
In order to follow a logical pattern I will break down your post. Sorry in advance for the lengthy quotations, but in this format I don't know of another way.
Regarding Bipedalism in Homo Sapiens and earlier hominids you state:
"The biggest hole in evolutionary theory is our own species, Homo Sapiens. Strictly speaking, as species go, our evolutionary design is terrible. We are physically the weakest species on the planet, because we walk erect. From an evolutionary design standpoint, it is a terrible design. All of our vital organs are exposed as a result, and all of our muscle groups must work against each other to hold us erect, making the energy available for lifting, grasping, running, etc far less than other designs.
Pound for pound there isn't a monkey or gorilla out there that doesn't far exceed us in the categories of physical strength and endurance, speed or dexterity. Many proponents state that our ability to stand erect is a result of our origins in the Savannah, where the ability to stand erect allowed us to sense danger more readily. as we could see much further this way. That would make a certain amount of sense, I suppose, if not for the fact that the predators we most likely would be trying to sense would not be standing erect, and as such our ability to see over the top of the grass would not be all that useful in spotting predators hiding in that same grass. It is also interesting to note that if this were indeed a desirable trait it is not a trait that man alone possesses. There are several other species that can stand erect when the situation calls for it, such as bears or even many species of ape.
So from an evolutionary standpoint, our ability to walk erect is actually a step backwards. The only reason we have survived as a species is thanks to our cognitive abilities. If, as evolution suggests, that man and ape had a common ancestor, it would have made far more sense from an evolutionary standpoint that the dominant species on this planet would have been far more akin to the ape in physicality but more intelligent. He would have walked only semi-erect, maintaining the lower profile and protecting his vital organs from attack as well as maintaining the superior strength and speed benefits.
Such a species would have been far more adaptable and survivable, and as such would have easily replaced us according to evolutionary theory. The only evolutionary advantage we have is our superior intelligence, and had both we and the ape evolved from a common ancestor as evolution suggests the natural evolutionary result would have been a creature that moves and carries itself like an ape and thinks like a man. Had we truly evolved from a common ancestor there is little doubt that our evolutionary path would have ended in a much different result, if the only guiding force in evolution was that of natural selection."
Here is your key statement regarding bipedalism: "So from an evolutionary standpoint, our ability to walk erect is actually a step backwards. The only reason we have survived as a species is thanks to our cognitive abilities."
No argument here that our large brains have greatly enhanced our ability to survive. The question is what allowed us to have large brains? In a word: Bipedalism.
This forwarded Human Evolution in 3 major ways. They are Encephelatic Development, Tool Making, and vocalization.For reasons of space and my personal time I will go into why bipedalism in hominids (including Homo Sapiens) is a positive evolutionary step within the context of Encephelatic Development. Should it be requested I will delve into tool making and vocalization.
Cranial Blood Flow and Encephalitic Capacity:
Previous to our becoming bipedal hominid species had an issue with heat exchange to and, more importantly, from the brain, much like other quadripeds. Heat exchange, or lack thereof limits cranial capacity. A bipedal organism experiences much less sunlight (and obviously heat exposure) than a quadriped. Also, as demonstrated by fossil evidence is evidence of increased vascular activity to and from the brain, both in quality and quantity. Meaning size and number of vascular pathways. Over time the advent of bipedalism “corrected” the heat exchange issue allowing us to be able to have larger cranial capacity previously limited by quadrapedal locomotion.
Here is some source material:
Dr. Dean Faulk is given credit for discovering that the development of the larger brain was dependent on walking upright. She determined the brain, like any other electrical device, generates heat and its size is dependent on its cooling capacity. Its development was proportional to sun exposure. Heat was intense on the savannas where the transition occurred and, as depicted in the drawing, the upright body attracted 17% less sunlight than a body on all four legs. It follows then that after the hip modification was complete for bipedalism, conditions were present for increased brain size.
Source: http://www.theodynamics.com/theoI/chapter3.html" title="http://www.theodynamics.com/theoI/chapter3.html" target="_blank"http://www.theodynamics.com/t...
Physiological alterations were needed to adapt to the differing effects of gravity on blood flow. The blood flow system in and around the brain gradually altered and had a cooling effect which then led to further expansion in brain size (Falk, 1990).
Source: http://radio.weblogs.com/0107127/stories/2003/ 01/12/foodAndHumanEvoluti on.html" title="http://radio.weblogs.com/0107127/stories/2003/ 01/12/foodAndHumanEvoluti on.html" target="_blank"http://radio.weblogs.com/0107...
Since larger brains are associated with greater cooling needs, they were selected for in conjunction with elaboration of a vascular mechanism for keeping brain temperature within safe limits. In a sense, the human brain (like the engine of a car) has a radiator that prevents overheating
What accounts for the different pattern of cranial blood flow that occurred in A. africanus compared to other early hominids in response to altered gravitational pressures associated with bipedalism? Possibly, gracile australopithecines slept in trees at night, and ventured into "mosaic" regions that included open grasslands during the day. Bipedalism would have allowed these little hominids to minimize the amount of body surface that was exposed to overhead sun, thereby reducing heat loads and facilitating adaptation to thermally stressful savanna habitats (Wheeler, 1988). If so, the vasculature of gracile australopithecines became modified in response to gravitational and thermal pressures that were associated with refinement of bipedalism in hot, open habitats. The result was the beginning of a cranial radiator network of veins that could help cool the brain under conditions of intense exercise. More important, once in place, this system was itself modifiable and capable of keeping up with the increasing thermolytic needs of an evolving (enlarging) brain.
Source: http://www.albany.edu/braindance/Theories.htm" title="http://www.albany.edu/braindance/Theories.htm" target="_blank"http://www.albany.edu/brainda...
Physiological studies of cranial blood flow in humans in reclining vs. upright postures suggest that selection for bipedalism was correlated with the establishment of epigenetic adaptations for delivering blood preferentially to the vertebral plexus of veins, depending upon momentary respiratory and postural constraints. The frequencies of vascular/osteological channels used to deliver blood to the vertebral plexus of veins were determined for samples of African pongids, various taxa of fossil hominids, and extant Homo sapiens. These channels include an enlarged occipital/marginal (O/M) sinus system, multiple hypoglossal canals, and foramina that conduct emissary veins: posterior condyloid, mastoid, occipital, and parietal.
Source: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&" title="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&" target="_blank"http://www.ncbi.nlm.nih.gov/e...;db=PubMed&list_uids= 3092672&dopt=Abstract
Given the above evidence, I think it is safe to say that bipedalism had a positive effect on cranial capacity of hominid species, including of course, the end result to date, Homo Sapiens. Which is of course diametrically opposite to Stepdad’s postulate that bipedalism is a “backwards evolutionary step”.
Stepdad mentions the Human Eye:
“Then you have structures such as the human eye. The eye is pretty much an all or nothing type of affair. In order to function all of the parts have to be there and they all have to be in working order and in the right proportions. How does something like this "evolve"? Why aren't the vast majority of species on this planet blind, and if we are looking at a process of natural selection (blind creatures have a disadvantage and as such went extinct) why aren't there thousands of species of blind creatures in our fossil record? How is it that a structure as complex as the eye, one that would lend no evolutionary advantage until it was complete (requiring vast amounts of time and random mutations), evolve? Sure, it's technically possible, but it would require a vast number of random mutations to explain, and most of these mutations would have no evolutionary advantage until the structure was complete. So, if random mutation and natural selection are the process by which we evolve, why did all of these random mutations that had no real evolutionary advantage survive and reproduce as opposed to those more numerous, non-mutated members of the species that had all the same evolutionary advantages until the eye structure was complete enough and complex enough to lend an advantage? Furthermore where is the fossilized record of all of these blind species that must have existed prior to the evolution of the eye? It really just makes no sense, if random chance and natural selection are the only means by which life progressed, that the eye would develop as a result. It would be far more likely that our world would be populated by species that are mostly blind, and only a few or even one would have achieved sight through evolution.”
Where even to begin? Lets start here”
“Zoologist Dan-Erik Nilsson demonstrates how the complex human eye could have evolved through natural selection acting on small variations. Starting with a simple patch of light sensitive cells, Nilsson's model "evolves" until a clear image is produced. Examples of organisms that still use the intermediary forms of vision are also shown. From Evolution: "Darwin's Dangerous Idea."
Source: http://www.pbs.org/wgbh/evolution/librar y/01/1/l_011_01.html" title="http://www.pbs.org/wgbh/evolution/librar y/01/1/l_011_01.html" target="_blank"http://www.pbs.org/wgbh/evolu...
Complex organs such as eyes can evolve gradually
Many creationists use the example of the human eye to debunk evolution. The argument goes like this:
The human eye is an extremely complex organ, with many parts working in unison for it to function - the lens, retina, iris, optic nerve, muscles etc. It would be impossible for such a thing to spontaneously pop into existence, and each of the individual parts are useless without the rest.
Well, I agree. That is a perfectly valid argument. However, no evolutionist would even consider suggesting that the eye simply appeared on some new-born primate a million years ago.
The eye evolved very slowly, over a long span of time, starting with a simple patch of light-sensitive cells, and evolving into it's present state. The following rough diagram illustrates the development:
The green represents the creature that is evolving, the pink represents light-sensitive cells. Imagine these changes happening over a period of two million years (which is a microscopic fraction of the history of the Earth), each generation of creatures only changing by a fraction of a percent).
A: The creature is blind. This has obvious disadvantages as it cannot see predators approaching, and has to rely on sound, smell etc.
B: A random mutation has given this creature a patch of light-sensitive cells (not a problem - see below). It can detect light and dark. A sudden change of light to dark could indicate a predator approaching, allowing the creature to defend itself (by fleeing, fighting etc.) and dramatically increase it's chances of surviving and reproducing. Which is more likely to survive long enough to reproduce - a creature that runs when a shadow passes over it, or one that stands still? Your skin is covered in cells/nerves that detect heat, pressure, taste, smell and so on. Light is not that much different (see below).
C: Two patches, one either side of the head have developed (no surprise, as symettrical mutations are very common). The creatures can now determine which side the shadow is approaching from, and run in the opposite direction (or it may distinguish open spaces from dark shelter, for instance). Again, a huge improvement in their chances of survival from a fairly small change in their body. Slugs and snails see like this (admittedly, they can't run very well, but who wants to eat a slug anyway?).
D: If the patch of cells becomes hollow, cup-shaped, it gives the ability to better determine the direction of light (a dome would work just as well, but would be easier to damage. Also, a hollow would help create greater contrast with well-defined shadows). One side of the cup will be better-lit than the other. This creature can therefore better determine the direction that a shadow is approaching from (or, again, find a dark shelter more easily).
E: The hollow deepens over time and starts to close in on itself. A photographer would recognise this a pin-hole camera. It will form a reasonable image on the cells (retina), allowing the creature to see shapes, not just differentiate between light and dark. The Nautilus (a marine mollusc) has eyes exactly like this.
F: A transparent membrane covers the pin-hole, forming a crude lens (alternatively, the eye may be filled with a transparent jelly). This will make the images formed on the retina much sharper as well as protecting the delicate surface from dirt and infections. The creature can see predators/prey much more clearly now.
G: Muscles around the lens develop, allowing the creature to alter the shape of the lens and change focus. Now it can clearly see objects close by or far away. This is how the eyes of most mammals (such as humans) function. The Chameleon's eyes are quite different - instead of changing the shape of the lens, muscles move the lens backwards and forwards to focus the image, in the same way that an auto-focus camera works.
Source: http://www.abarnett.demon.co....
You further state:
“Welcome to the current state of affairs in our public schools. The Theory of Evolution is now being taught as scientific fact and being misrepresented to give the students the impression that there can be no God, no Supreme Being, no Creator. Sad but true.”
The Theory Of Evolution is taught as The Theory Of Evolution. You have neglected to mention anywhere in your post how it is taught as fact. I challenge you to name one case where this is so and source it.
Update #1:
There is no fossil evidence of a "Transitory Species"
There is no evidence of a “transitory species”? I am not sure what a transitory species is. I think you have a fundamental misconception about Evolution. There is no static state for organisms of any kind. All species are dynamic. The process is continuous. Therefore all species are transitory.
I am guessing however that what you are asking for is fossil evidence of organisms evolving into other organisms? In regards to Human Evolution what exactly do you think, Homo Sapiens Neandertalensis, Homo Sapiens, Homo Erectus, Homo Habilus, Australopithecus Robustus, Australopithecus Afarensis, and Australopithecus Ramidus are? These are our ancestors. Although the line is not always direct.
For instance, there is considerable evidence that we did not directly come from the Australopithecus Robustus line. They split off genetically speaking earlier and then died out. Thus making them an indirect ancestor. Sapiens Sapiens followed the Autralopithecus Afarensis line that continued through Homo Erectus and so forth. That is still in existence today, namely us.
Even within our species there is considerable fossil evidence of these species as that’s how we discovered them. Of course, much remains to be done. Complete fossils millions of years old of our ancestors are hard to come by. Relatively speaking, research has just begun. New fossils are found all the time.
One very recent example is the so called “hobbit” skeleton found in Flores’ cave last October. Early indictaors are that this newly discovered species lived much closer in time to us than all of the others ones. I have read estimates that it may have been possible for them to live as early as 500 years ago. Other estimates are are considerablly earlier but still far closer than othe known ancestors. Again, much more research needs to be done.
That to me is plenty of evidence of the misnomered “Transitory Species” that you speak of. As well as fossil record evidence.
Source: http://www.wsu.edu:8001/vwsu/gened/learn-mo dules/top_longfor/timelin e/timeline.html
Source: http://www.talkorigins.org/faqs/homs/" title="http://www.talkorigins.org/faqs/homs/" target="_blank"http://www.talkorigins.org/fa...
Source: http://www.india-overland.com/The" title="http://www.india-overland.com/The" target="_blank"http://www.india-overland.com...%20Origin%20of%20Species.html
Source: http://news.nationalgeographic.com/news/2004/10/1027_041 027_homo_floresiensis.html#main" title="http://news.nationalgeographic.com/news/2004/10/1027_041 027_homo_floresiensis.html#main" target="_blank"http://news.nationalgeographi...
Update #2:
Stepdad contends that one of the problems with the Theory of Evolution is how life formed here on Earth. Apparenly, has a problem with how organic life developed from inorganic material. Specifically mention ing amino acids and protein formation.
I beg to differ. This has been tested and is repeatable in a lab.
An exerpt form the this source: http://mediatheek.thinkquest....~ll125/en/life-2.htm
In 1924 Alexander Oparin hypothesized that organic compounds where formed in the early earth when the high energy provided by UV Rays, and storms, caused different molecules to react, and create new organic compounds, such as Amino Acids DNA, and RNA.
In the early 1950s, Professor Harold Urey and one of his students, Stanley Miller, began experimenting to prove Oparin's theory. Miller built an apparatus which circulated gasses likely to be present in the early atmosphere (Methane (CH4), Ammonia (NH3), Water (H2O), and hydrogen (H2) ) past an electrical discharge, simulating the UV Rays and violent electrical storms present in the early atmosphere.
After allowing the experiment to continue for a week, the results where startling. The previously colorless solution inside the apparatus had turned red. Upon analyzing the solution, Miller found many organic molecules present, some of which couldn't be readily identified. The most important of created compounds, however, where amino acids. This, in effect, proved Oparin's theory that organic compounds could have been created in the early atmosphere. Further studies showed that some amino acids would have combined with hydrogen cyanide (HCN), which is a byproduct of volcanic activity. This combination would form purines and pyrinidines, which are used to make nucleic acids, which in turn create DNA
After these compounds had been created on the early earth, the earth eventually began to cool. Water vapor the condensed, which formed vast oceans, seas and lakes, in which simple organic molecules began to accumulate for millions of years, producing an "organic soup" of sorts. The amino acids would have then polymerized (which means they formed chains, such as proteins. E.g... (aa=amino acid) aa-aa-aa-aa-aa = protein). The most likely theory as to how the amino acids combined is that they where washed up into clay/rock depressions on land, where the water evaporated, leaving behind concentrated organic compounds in high heat.
Sidney W. Fox set out to prove this. He took a mixture of approximately 20 different amino acids, and heated then to the melting point. When they cooled, Fox observed that they had polymerized into proteins.
So much for that idea.
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