Evolution: What is your take on it?

[Sanguvixen]

I notice that within the other parts of Gaia and in a forum site that I no longer participate in: That whenever atheists go against religious people and debate starts, Evolution usually crops up. The religious have a tendacy to point accusing fingers with the word Evolution. They act as though it is some awful swear word.

I've been asked "Do you believe in Evolution?"

Now I can perfectly admit that the Theory of Evolution still has some holes. I can also point out that the Bible has more holes.

There are however some very valid parts of it (Evolution) that has relevence to real history. Or have people not noticed that Micro-evolution is real...and that is why we have to keep coming up with newer medications to evade the evolving illnesses that strike our kin down.

Firstly...Humans do have Tail-bones. Or more accurately, the remnant of a tail-bone. To me that implies that we once had tails. For some reason the religious never quite come up with a response to pawn that obvservation. Usually it gets ignored.

Secondly...Humans are 99% genetically identical to the Chimpanzee.

Thirdly...There have been remains found of all sorts of humanoid species..that appear to possibly have been sentinant beings.

Here is a interesting story I ran across:

http://news.nationalgeographic.com/news/2006/03/0308_060308_all_fours_2.html

It talks about humans who were born with the inability to walk upright...they are quadreped humans. There are 4 living in Turkey.

Also, people have found remains of Pigmy Humans. If you don't beleive me:
http://blogs.nationalgeographic.com/channel/blog/2005/03/explorer_hobbit.html

These people who cling to the fact that the Theory is still incomplete...blatently refuse to admit that the Bible itself has holes.
They will say that it was written by man, and man is imperfect...hence the flaws of the Bible. So...if they admit that it is flawed...why do they follow it?

So...if it was written by man...where does the God come in? I remember hearing somewhere inside a Church that "God" created man in the image of himself. Does that not mean that if he created imperfect beings, that he himself is imperfect...and therefore probably doesn't exist?

Anyway, after the Theory of Evolution popped up stirring intense religious and scientific debate, the religous came up with Creationism to counter Evolution and later on tried to dress up Creationism as science by changing it's name to Intelligent Design. For some reason that thing still makes me laugh...at the idiocy.

So...as if the discussable topic isn't already obvious:

What is your opinion (backed by some fact) of Evolution?
What is your opinion (backed by some fact) of Creationism?
What is your opinion (backed by some fact) of Intelligent Design?
What is your opinion (backed by some fact) of the flaws of the bible?

 

[Lesilrok]

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[Lesilrok]

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[Lesilrok]

There is not just one technique to date items that are found by scientists. Many creationists attack the methods of dating simply because they do not sync up with the < 10,000 year old biblical time.

Relative Dating:

Stratigraphy is used as relative dating. It utilizes the sedimentary layers of rock to determine what came before what. The older the layer or "strata", the further down it will be.

Stratigraphy

Pojcta and Springer

In the mid-1600's, about 200 years before Darwin published his theory of evolution, the Danish scientist Nicholas Steno found that it was possible to establish the order in which layered rocks were deposited.

...in any sequence of undisturbed layered rocks, a given bed must be older than any bed on top of it. This Principle of Superposition is fundamental to understanding the age of rocks; at any one place it indicates the relative age of the rock layers and of the fossils they contain.

If we begin at the present and examine older and older layers of rock, we will arrive at a level where no human fossils are found. If we continue backward in time, we successively come to layers where no fossils of birds are present, no mammals, no reptiles, no four-footed animals, no fishes, no shells, and no members of the animal kingdom. These concepts are summarized in the general principle called the Law of Fossil Succession. (14-15).

Quote:

Geologists create a relative time scale using rock sequences and the fossils contained within these sequences. The scale they create is based on The Law of Superposition, which states that in a regular series of sedimentary rock strata, or layers, the oldest strata will be at the bottom, and the younger strata will be on top. Danish geologist Nicolaus Steno (also called Niels Stensen) used the idea of uniformity of physical processes. Steno noted that sediment was denser than liquid or air, so it settled until it reached another solid. The newer sediment on the top layer is younger than the layer it settled upon. Since this is what happens in the world today, it should also determine how rock layers formed in the past. Crosscutting relationships are also used to determine the relative age of rocks. For instance, if a thin intrusion of granite, called a dike, cuts through a layer of limestone, the granite must be younger than the limestone.

From: http://encarta.msn.com/encyclopedia_761555455/Geology.html

The age of the earth as being older than what biblical text allows was accepted far before modern times and before Darwin's voyage on the Beagle.

Levin

From the time of Hutton [Jame Hutton (1726-1797)], leaders in the scientific community were convinced that the Earth was indeed very old, and certainly it was much older than the approximately 6000 years estimated by biblical scholars from calculations involving the ages ot post-Adamite generations. (1 cool

There is also fluorine analysis.

Jurmain, Nelson, Kilgore and Trevathan

Another method of dating is fluorine analysis, which only applies to bones. Bones in the earth are exposed to the seepage of groundwater that usually contains fluorine. The longer a bone lies in the earth, the more fluorine it will incorporate during the fossilization process. Therefore, bones deposited at the same time in the same location should contain the same amount of fluorine. (234)

Relative Dating and Fluorine Analysis

http://id-archserve.ucsb.edu/Anth3/Courseware/Chronology/01_Contents.html

Many methods were devised to extrapolate the age of the earth. However, with the discovery of radioactivity, our ability to say with certainty what the age was found its backing.

Radioisotope Dating:

This dating, called absolute dating, utilizes the decay of radioactive isotopes as clocks for dating materials. The most widely known method is the C-14 which has a half life of 5,730 years.

How Carbon-14 Dating Works

Plummer, McGeary and Carlson

...radiocarbon dating is useful only in dating things and events accurately back to about 40,000 years -- about seven half-lives. (However, new techniques allow some scientists to push the limit to nearly double that time.) (191)

Radiocarbon Dating

C-14 dating isn't the only method available though. Other methods include: Uranium-Lead method, potassium-argon method, rubidium-strontium method for example. Each has a different half-life and a range of time it can date accurately.

So what makes these isotopes "absolute dating"?

Levin

The rate of decay of radioactive isotopes is uniform and is not affected by changes in pressure, temperature, or the chemical environment. Therefore, once a quantity of radioactive nuclides has been incorporated into a growing mineral crystal, that quantity will begin to decay at a steady rate with a definite percentage of the radiogenic atoms undergoing decay in each increment of time. Each radioactive isotope has a particular mode of decay and a unique decay rate. (21)

Plummer et al disucsses the radioactive decay of isotopes:

Plummer et al.

Radioactive decay is the spontaneous nuclear change of isotopes with unstable nuclei. Energy is produced with radioactive decay. Emissions from radioactive elements can be detected by a Geiger counter or similar device, and, in high concentrations, can kill humans.

Nuclei of radioactive isotopes change primarily in three ways. An alpha emission is the ejection of two protons and two neutrons from a nucleus. When an alpha emission takes place the atomic number of the atom is reduced by two and its atomic mass number is reduced by four. After an alpha emission, U-238 becomes Th-234, which has an atomic number of 90. The original isotope (U-23 cool is referred to as the parent isotope. The new isotope (Th-234) is the daughter product.

Beta emissions involve the release of an electron from a nucleus. To understand this, we need to explain that electrons, which have virtually no mass and are usually in orbit around the nucleus, are also in the nucleus as part of a neutron. A neutron is a proton with an electron inside of it, thus it is electrically neutral. If an electron is emitted from a neutron during radioactive decay, the neutron becomes a proton and the atom's atomic number is increased by one.

The third mode of change is electron capture, whereby a proton in the nucleus captures an orbiting electron. The proton becomes a neutron. The atom becomes a different element having an atomic number one less than its parent isotope. (189-190)

Despite the attacks thrown by creationists, radioisotope dating gives us an extremely accurate timeframe for the age of fossils, artifacts, minerals, etc. Cross-checking is also used in conjunction with radiometric dates to obtain the most accurate and reliable date

A Radiometric Dating Resource List

Isochron Dating by Chris Stassen

Radiometric Time Scale

Radiometeric Dating Does Work! by G. Brent Dalrymple

Radiometric Dating and the Geological Time Scale: Circular Reasoning or Reliable Tools? by Andrew MacRae

More to come later.

REFERENCES:

Jurmain, R., Nelson, H., Kilgore, L., & Trevathan, W. (2000). Introduction to physical anthropology (8th ed.). Belmont: Wadsworth/Thomson.

Levin, H. (1999). The earth through time (6th ed.). Orlando: Harcourt Brace.

Plummer, C., McGeary, D., & Carlson, D. (2003). Physical geology (9th ed.). New York: McGraw Hill.

Pojcta, J. & Springer, D. Evolution and the fossil record (2001). Alexandria: American Geological Institute.  

[Lesilrok]

Natural Selection and other mechanisms of Evolution:

Natural Selection is defined by Audesirk as:

Audesirk et al.

the unequal survival and reproduction of organisms due to environmental forces, resulting in the preservation of favorable adaptations. Usually, natural selection refers specifically to differential survival and reproduction on the basis of genetic differences among individuals. (G-16) [1]

Natural selection is one of the most important if not the most important item in describing and researching into evolution. It is also probably the least well understood concept by the general public. People are fired at with phrases like "survival of the fittest" which was first coined by Herbert Spencer in support for his Social Darwinism which is a social theory and NOT a biological model for evolution.

Jurmain et al. describe natural selection in action by telling about the peppered moth:

Jurmain et al.

A well-documented case of natural selection acting in modern populations concerns changes in pigmentation among peppered moths near Manchester, England.



Before the nineteenth century, the common variety of moth was a mottled gray color. This light, mottled coloration provided extremely effective camouflage against lichen-covered tree trunks. Also present, though less common, was a dark variety of the same species. While resting on light, lichen-covered trees, the dark, uncamouflaged moths were more visible to birds and were therefore eaten more often.

Thus in the end, the dark moths produced fewer offspring than the light, camouflaged moths. Yet, by the end of the nineteenth century, the common gray form had been almost completely replaced by the black variety.

What brought about this rapid change? The answer lies in the rapidly changing environment of industrialized nineteenth-century England. Coal dust in the area settled on trees, killing the lichen and turning the bark a dark color. Moths continued to rest on trees, but the gray (light) variety was increasingly conspicuous as the trees became darker. Consequently, they began to be preyed on more frequently by birds and contributed fewer genes to the next generation.

In the late twentieth century, increasing control of pollutants allowed trees to return to their lighter, lichen-covered, preindustrial condition. As would be expected, the black variety of moth is now being supplanted by the gray. (35-36) [2]

This is where the misunderstanding that "fitness" is a tautology. What may incur a benefit to a species at one point in time may become a deteriment later.

For some, the idea that fitness equals "power" or "being bigger and stronger" is inescapable and promotes the misunderstanding of natural selection.

Drickamer et al. comments on this:

Drickamer et al.

...the adaptive value of certain genes or genotypes depends on existing environmental conditions. A genotype may have high fitness in one environment, but low fitness in another. Fitness is therefore not an unchanging characteristic of an organism, such as eye color, but is determined by both the organism's characterstics and the environment.

How should fitness be measured...We gnerally test our hypotheses about fitness of different genotypes and phenotypes by measuring the reproductive success of the organisms in question. Reproductive success is a measure of an organism's production of offspring. It may be measuredc in several ways, including the number of offspring born, the number that survive to weaning, or the number that survive to mating.

Fitness is a property of traits or genotypes, while reproductive success is a property of individuals. (4 cool [3]

Drickamer's last note points out another area of ignorance about natural selection. Natural selection works upon individuals BUT it is populations that evolve.

Natural selection is also evident in strains of bacteria that become resistant to antibiotics.

Natural selection should not be confused with artificial selection. Artificial selection is evident in domestic dog breeding. Alters comments on this:

Alters

Artificial selection is based on the natural variation all organisms exhibit.

By choosing organisms that naturally exhibit a particular trait and then breeding that organism with another of the same species exhibiting the same trait, breeders are able (over successive breedings) to produce animals or plants having a desired, inherited trait. (534) [4]

Natural Selection

How Natural Selection Works

http://anthro.palomar.edu/evolve/evolve_2.htm

Next time:

Types of selection
Genetic Flow
Speciation

References:

1) Audesirk, T., Audesirk, G. & Byers, B. (2002). Biology: Life on earth. (6th ed.). Upper Saddle River: Prentice Hall.

2) Jurmain, R., Nelson, H., Kilgore, L. & Trevathan, W. (2000). Introduction to physical anthropology. (8th ed.). Stamford: Wadsworth/Thomson.

3) Drickamer, L., Vessey, S. & Jakob, E. (2002). Animal behavior: Mechanisms, ecology, evolution. (5th ed.). New York: McGraw Hill.

4) Alters, S. (2000). Biology: Understanding life. (3rd ed.). Sudbury: Jones and Bartlett  

[Lesilrok]

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[Lesilrok]

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[Lesilrok]

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[Lesilrok]

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[Lesilrok]

ms. sanguvixen,

I kind of assumed you would want some information and I posted this info on another forum board. These are facts crediting my opinion and you were somewhat assertive when it came to provide by facts so I did.

I hope this is enough facts for you and I will find more info when I do my homework.

as for flaws in the bible I do not want to take anymore post space so I will give this link. It is a website that I help created. It points out a whole lotta contradictions and inconsistencies in the bible.

www.skepticsannotatedbible.com

Hope this is enough for you guys smile  

[Dathu]

Wow. All four years of High School science and Bio 101 in one post.  

[Riratio]

I read about half of it. Lots of good info you guys collected. :3  

[Orson Welles]

shinobikun

Hope this is enough for you guys smile

It's more than enough. 3nodding  

[Sanguvixen]

Wow...Thanks Shino! I'll try to look through all of that...it should be helpful.

 

[GEt CrUnK iTs BiLlY!]

I was planning on giving my opinion but there is nothing that so thanks for saving me time biggrin