Humans are 6,000 years old...promise!

by notsurewheretogo 15 Replies latest watchtower beliefs

• 

  bohm

  Crazyguy: Check out the original article, this is the primary reference for the age of the remains in the cave:

  http://www.ncbi.nlm.nih.gov/pubmed/9300339

  They used Uranium-series dating method, see here:

  http://en.wikipedia.org/wiki/Uranium-thorium_dating

  Notice the date, when matched up against the (statistically estimated) date of the mRNA fragments match up with the date in the above reference. Ie. using two vastly different dating methods we arrive at roughly the same age of about 400'000 years.
• 

  Bugbear

  I think the GB must be rather conspiratorial trying to establish their Bible chronology against modern sciense. They probable stick their heads in the sand, not listening, not hearing, not seeing, not talking. If they did anything of that, their empire will be ruined and totaly destroyed in e few month.

  But more and more people are getting better and better education, and people have better and better assets to information. The real enlightenment time has just arrived.

  Bugbear
• 

  Perry

  Here's an interesting link that should keep anyone new to the subject busy for quite a while.

  http://s8int.com/article1-simple.html
• 

  bohm

  Perry, I see you are selectively quoting 10+ year old tentative research which support your conclusion while ignoring all subsequent research. Sorry, it turned out the facts dont align with your pre-consieved ideas on this subject either, you need to go back to ignore them.

  ---

  For those interested, here is a description of the current research

  My summary: When better methods was made available to sequence mRNA, and the results could be build on more data, the data turned out to disconfirm the 6000-years old model for humans:

  http://www.evolutionpages.com/Mitochondrial%20Eve.htm

  Conclusion

  No-one in the science community thought that the Parsons et al study supported a matrilineal MRCA of 6,500 years. Nevertheless their work did result in discrepancies between the known date of human geographic dispersion (at least 60,000 years BP) and the apparently very high rate of mitochondrial mutation, which, if taken at face value, would yield a matrilineal MRCA 6,500 years ago.

  Subsequent studies have shown the following:

  • RFLP analysis (as used by Parsons et al and Howell et al) is not a an appropriate approach to determine mutational rates; whole genome sequencing as used by Ingman et al is more accurate
  • There is considerable disagreement between different studies of mutational rate, as measured by pedigree analysis of near relatives, concentrating on the D-loop
  • Some of this variation is simply the result of stochastic variations in small sample sizes
  • Much of this variation is due to genuinely different mutational rates on the D-loop in different populations
  • The rate of fixed mutations over many generations is much lower than the instantaneous mutational rate from generation to generation as a consequence of the elimination of slightly deleterious mutations from the gene pool
  • The presence of mitochondrial heteroplasmy will result in an elevated mutational rate in pedigree studies
  • The fixed mutational rate outside the D-loop over many generations is constant across primate species and can be used as an accurate mutational 'clock'
  • A study of a representative sample of humans from the worldwide population using whole genome analysis and excluding the D-loop yields an age for matrilineal MRCA (Mitochondrial Eve) of 150,000 to 200,000 years
  • The same humans give an X-chromosome MRCA of ~480,000 years as predicted.

  It seems to be the nature of creationist apologists to misrepresent and misuse scientific work. The fact that so many creationists and creationist websites latch on to the Parsons et al paper ,and claim that it is proof for a biblical Eve living 6500 years ago, (even though Parsons et al claim no such thing), demonstrates two things:

  1. They do not understand or they deliberately misrepresent the concept of the matrilineal Most Recent Common Ancestor which does not point to the only female human ancestor
  2. They ignore the fact that subsequent research has largely resolved the issues that the Parsons et al paper raised.

  It is my confident prediction that both ill-informed creationists and those who should know better will be using this discredited argument 20 years from now. They will be as wrong then as they are now.
• 

  Tiktaalik

  To answer data-dog's question:

  Almost anything can be dated using one of the several radiometric clocks, depending on how far back in time you wish to date.

  Several elements are useful for dating purposes, because they can exist in different forms, or isotopes. An isotope is an element whose atoms have a different amount of neutrons in their nucleus. This gives the isotopes different properties and usually renders them unstable. This instability means that they decay at a set rate over time, and this is how they can be used to date objects.

  For dates stretching back to around 50,000 years isotopes of carbon are very useful and accurate. Carbon dating measures the abundance of the isotope carbon 14 (that is carbon with an extra 2 neutrons in its nucleus, normal carbon has 12) in the material you are seeking to date. Carbon 14 is formed in the atmosphere when high energy rays from the sun strike atoms of nitrogen and form carbon 14. The rate of creation equals the rate of decay, so the overall proportion of carbon 12 to carbon14 remains the same over time.

  All living things take up carbon 14 in the same relative abundance as it exists in the environment. Some of the carbon atoms in our bodies are actually carbon 14, and this is proportional to the abundance in the background environment. When we die, however, the intake of all carbon is halted. The proportion of carbon 12 does not change as it is stable, but the proportion of carbon 14 begins to decline. For the first time in the organism's existance, the ratio of c12 to c14 begins to differ from the normal background level. Because c14 decays at a known rate, the difference between the c12:c14 ratio in the object you are dating to that in the surrounding environment provides you with an accurate date on when that organism died.

  As I said earlier, carbon dating, or more accurately, radiocarbon dating since carbon 14 is radioactive, is only useful for dating objects no older than around 50,000 years. For objects older than that other radiometric clocks with other elements are used. Radioactive decay is termed the half-life. This is the time it takes for the one half of an unstable isotope to decay into a more stable (not radioactive) form. Carbon 14 has a half-life of around 5700 years. Other elements have much longer half-lives. One isotope of uranium has a half-life of around 80,000 years, so it was most probably used to date the bone sample above.

  Rocks can be dated many different ways, including radiometric dating. Other elements have much longer half-lives, stretching into the millions and even billions of years. These slower clocks are very useful for dating very old rocks.

  I hope that helps to answer your question.
• 

  bohm

  Tiktaalik: both c14 and Uranium series dating was used on the reamains in the cave, however for the older human bones it was u series dating as you point out. From the paper cited in the nature paper which i linked above:

  Sediments of the Sima de los Huesos vary greatly over distances of a few meters. This is typical of interior cave facies, and caused by cycles of cut and fill. Mud breccias containing human bones, grading upwards to mud containing bear bones, fill an irregular surface cut into basal marks and sands. The lack of Bedding and the chaotic abundance of fragile speleothem clasts in the fossiliferous muds suggests that the deposit was originally a subterranean pond facies, and that after emplacement of the human remains, underwent vigorous post-depositional rotation and collapse and brecciation, caused by underlying bedrock dissolution and undermining. The fossiliferous deposits are capped by flowstone and guano-bearing muds which lack large-mammal fossils. U-series and radiocarbon dating indicates the capping flowstones formed from about 68 ka to about 25 ka. U-series analyses of speleothem clasts among the human fossils indicate that all are at, or close to, isotopic equilibrium (> 350 ka). The distribution of U-series dates for 25 bear bones (154 +/- 66 ka) and for 16 human bones (148 +/- 34 ka) is similar and rather broad. Because the human bones seem to be stratigraphically older than chose of the bears, the results would indicate that most of the bones have been accumulating uranium irregularly with time. Electron spin resonance (ESR) analyses of six selected bear bones indicates dates of 189 +/- 28 ka, for which each is cordant with their corresponding U-series date (181 +/- 41 ka). Combined ESR and U-series dates for these samples yielded 200 +/- 4 ka. Such agreement is highly suggestive that uranium uptake in these bones was close to the early-uptake (EU) model, and the dates are essentially correct. Another three selected samples yielded combined ESR U-series dates of 320 +/- 4 ka with a modeled intermediate-mode of uranium uptake. The dating results, therefore, seem to provide a firm minimum age of about 200 ka for the human entry: and suggestive evidence of entry before 320 ka.