"Scientists have developed more than a dozen methods for determining the age of fossils, human artifacts, and the sediments in which such evidence is found." Various methods have dated some human remains older than 100,000 years.
New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens
" What’s more, the methods can be tested against one another to provide a highly reliable record of the past."
" Here of some of the well-tested methods of dating used in the study of early humans:
- Potassium-argon dating, Argon-argon dating, Carbon-14 (or Radiocarbon), and Uranium series. All of these methods measure the amount of radioactive decay of chemical elements; the decay occurs in a consistent manner, like a clock, over long periods of time.
- Thermo-luminescence, Optically stimulated luminescence, and Electron spin resonance. All of these methods measure the amount of electrons that get absorbed and trapped inside a rock or tooth over time.
- Paleomagnetism. This method compares the direction of the magnetic particles in layers of sediment to the known worldwide shifts in Earth’s magnetic field, which have well-established dates using other dating methods.
- Biochronology. Since animal species change over time, the fauna can be arranged from younger to older. At some sites, animal fossils can be dated precisely by one of these other methods. For sites that cannot be readily dated, the animal species found there can be compared to well-dated species from other sites. In this way, sites that do not have radioactive or other materials for dating can be given a reliable age estimate.
- Molecular clock. This method compares the amount of genetic difference between living organisms and computes an age based on well-tested rates of genetic mutation over time. Since genetic material (like DNA) decays rapidly, the molecular clock method can’t date very old fossils. It’s mainly useful for figuring out how long ago living species or populations shared a common ancestor, based on their DNA."
Frequently Asked Questions
Based on overwhelming fossil evidence as well as genetic evidence...I
don't believe, but accept as fact, there's been a significant enough gene pool alteration within a species changing over the course of many generations resulting in organisms having genetic traits different enough from their distant ancestors; so that there'd be no possible sexual reproduction occurring between somebody who were to have distant ancestral genetic traits with anybody living in the current population. There's little doubt all life forms share a common ancestor; so then, evolution is about as debatable as the Earth's ellipsoid shape.
ERVs provide the closest thing to a mathematical proof for evolution.. ERVs are the relics of ancient viral infections preserved in our DNA. The odd thing is many ERVs are located in exactly the same position on our genome and the chimpanzee genome! There are two explanations for the perfectly matched ERV locations. Either it is an unbelievable coincidence that viruses just by chance were inserted in exactly the same location in our genomes, or humans and chimps share a common ancestor. The chances that a virus was inserted at the exact same location is nearly 1 in 3,000,000,000. Humans and chimps share 7 instances of viruses inserted at perfectly matched location. It was our common ancestor that was infected, and we both inherited the ERVs.
Johnson, Welkin E.; Coffin, John M. (1999-08-31).
"Constructing primate phylogenies from ancient retrovirus sequences".
Proceedings of the National Academy of Sciences. 96(18): 10254–10260.
Bibcode:
1999PNAS...9610254J.
doi:
10.1073/pnas.96.18.10254.
ISSN 0027-8424.
PMC 17875.
PMID 10468595