jtrhart

Rapid Human Evolution

In Uncategorized on December 11, 2007 at 2:46 pm

I found an article Reuters has posted on current research into human evolution traits over time. John Hawks out of the University of Wisconsin has been looking into what specific physical traits have evolved in humans over the past few millions of years. I think the article can be summed up as quoted below

The central finding is that human evolution is happening very fast — faster than any of us thought

and, from the article

In fact, people today are genetically more different from people living 5,000 years ago than those humans were different from the Neanderthals who vanished 30,000 years ago

The traits this research focused on were not the physical traits (big forehead, lots of hair, big noses) that we typically think of when we think of the pictures of Neanderthals that saturate our museums and elementary school text books, but rather the less visible ones (ear wax, ability to digest milk, disease resistance, etc.). Therefore, this is not a case against the micro-evolution that most evolutionists hold to today since we are not talking about sweeping changes in human-body structure. But it is interesting to point out that this research seems to imply that the humans we are today came about very rapidly in the past 5,000 years; which is about the age of the earth if you ask someone who believes in a literal interpretation of the book of Genesis.

But There Are Still 30,000 Year Old Bones

The question still remains though, if we have human bones from 30,000 years ago we would have to throw out the literal Genesis account of creation, so how do we reconcile this? Let’s look at the method used to date these human remains.

Carbon Dating

Carbon dating will calculate the age of carbon in a specimen based on how much carbon is left when you find it. Since carbon decays at a known rate, you can calculate an age given the current amount found in a specimen. The rate at which carbon decays is based on the amount of C14 in the atmosphere during a specimen’s lifetime. This is where carbon dating breaks down. The amount of C14 in the atmosphere has not been constant over time. For instance, the amount of C14 doubled for a little while during the 1950’s and 1960’s (when atomic weapons testing was done above ground anywhere there was available space). Natural conditions affect the amount of C14 as well; climate changes, solar storms, amount of organic matter existing, etc.

Scientists have attempted to fix this issue by looking at items with known ages and measuring their amount of carbon and then calibrating based on these values. So, as an example, we can take a tree and count its number of rings and determine its age (1 ring = 1 year of life) and measure its carbon quantity and match up the age of the tree and the age of the bone. But again this method relies on a constant ecological environment during the tree’s lifetime. For example, during periods of rapidly changing climates, trees may grow faster or slower and hence would not gain 1 ring per year. Apart from the non-constant growth cycle, you have the bigger problem of taking two objects that did not begin their life-cycle together and attempting to base one’s age on the other’s. Let’s say I date a tree at 20,000 years old and then use that tree’s age to calibrate for a 10,000 year old bone, I cannot just assume that a tree’s previous 10,000 years would not have any effect on it’s aging characteristics for the next 10,000 years. I would have to calibrate using a specimen that began its life at the same time the bone (and whoever it was attached to) did. And even if I could do that, I would only be basing the bone’s age on the tree’s age, but the tree’s age is based on the bone’s age because I had to use a tree that was the same age as the bone’s. And so you have an iterative calculation method without a lot of specimens to choose from (we have about 270 samples which are older than 5,000 years).

The Variable Truth

In the end, what we have is methods which rely on assumptions to determine their results. What if the world flooded 4,000 years ago? Certainly something this massive in scale would throw off a formula which is based on things remaining fairly constant through-out their life-span.

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