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One of the facets of social media is it allows lots of people to voice all kinds of opinions, and make all sorts of wonderful assertions. Micro-blogging sites like twitter are accessible to people with often, nothing more than a cellphone.

This has also meant that the various species of creationists wanting to popularise their views, are a constant plague. So, I thought I’d occasionally dip into the timelines, extract the odd mirthful assertion, and have a closer look.

This one is from @joecienkowski who tweets:

@xxxxxx how you explain 96% reduction in human population in only 2010 years & expect to go much more than few thousand years past.

Okay, Joe is a Young-Earth-Creationist who believes that the earth is really just a few thousand years old. What he’s doing is recycling an old argument that if we interpolate the human population growth rates back in time, then we run out of people in just a few thousand years.

What this really does is just take a very simplistic Lotka population model. Yeah, biologists know about these kinds of things. And it’s based solely on the ‘natural rate of increase’, which is assumed to be constant. So nothing that moderates actual population increases- disease, food supply, predation, wars- actually exist in this model. It’s completely absurd reasoning.

The absurdity should be made obvious by considering the analogous Elephant Population Theory. This was actually highlighted by Darwin [1]. Assuming we start with 2 elephants- and that each female elephant breeds six offspring between the ages of 30 and 90, then there would be 19 million elephants in just 750 years. That’s assuming of course, there’s enough food supply.

Assuming we start from a global flood at 2350 BCE, we begin with one pair of African elephants. In 1000 years, there’d be 87,346,358,195 elephants. By the Augustan Era in Rome  there’d be a global population of 20,208,533,156,611,200,000,000,000 elephants.  That’s like over 20,000 billion billion billion elephants. You’d think people might have noticed.

It also fails for the obvious reason that for most of the human population’s history, growth rates have been very close to zero. It has taken both the development of agriculture- and more recently industrialisation- to lift our population’s growth rates.

The genetic evidence also provides strong backing for evolution.  The recent paper by Huff et.al (2010) [2] used Alu (mutational) insertions to identify that the effective population of human ancestors living 0.9 to 1.5 million years ago was  14,500- 26,000. The reason human populations stayed so low for hundred of thousands of years is simple. There was almost no discernible  population growth.

This highlights another dilemma for YEC. The mutation rate in humans is about 130 per births [3]. This is simply not sufficient to generate the variation in human characteristics that we see today in the short, ‘few thousand’ YEC time frame.

References

[1] Darwin, C. The Origin of Species, Chapter III

[2] Huff, C.D., Xing, J. Rogers A.R., Witherspoon, D. and Borde, L.B.(2010) PNAS, 107(5): 2147-2152

[3] Nachman, M.W., Crowell, S.L. (2000) Estimate of the mutation rate per nucleotide in humans. Genetics 156:297-304