Tick, tock, tick, tock

For almost twenty-five years a wedding gift has hung in our hallway or living room. That battery powered wooden framed clock has marked the passage of seconds, minutes and hours for decades.

Such clocks are not the only ones. The earth is filled with many different types of clocks, some more accurate than others. Tides regularly wax and wane. Trees experience periods of rapid growth and then dormancy thus producing tree rings.

A new clock has been identified. From our mothers we inherit a slightly imperfect copy of her mitochondrial DNA. Experimentation has identified the rate at which human mitochondrial DNA mutates./1

What is fascinating about this clock is that these cellular energy factories we call mitochondria can point backward in history toward the origin of humanity.  How is this possible?

By knowing how many mitochondrial DNA mutations exist between different individuals as well as the rate at which mutations occur, we can calculate how long it has been since a common mitochondrial mother was shared! How far back does it go?

Given the rate at which our mitochondrial DNA mutates, if humanity has been around for some 180,000 years as standard human evolution affirms, then we should expect to find about 174 mutational differences between some humans. Grant some wiggle room, the expectation is for at least 124 mutational differences but no more than 290.

So what does the laboratory actually reveal?  On the average, humans have exhibited 10 mitochondrial DNA differences, nowhere near the expected 174. A mere 10 mutations places our common mother in the neighborhood of 10,000 years ago.

The evidence gets more interesting.  Mitochondrial DNA mutation rates for fruit flies and round worms have also been determined.

Standard evolutionary theory proposes that the round worm appeared 18 million years ago while the fruit fly emerged some 20 million years ago. Yet, measuring their mitochondrial DNA mutations indicate these creatures appeared about the same time as humanity.

The earth is full of clocks: radioactive decay, the accumulation of atmospheric helium, the increasing salinity of our oceans, and so forth.

A strong temptation exists to accept as reliable only those clocks producing the answers we might like, whatever those might be.  Conversely, it also entices us to manufacture stories and fabricate explanations to dismiss the testimony of dissenting clocks. This can cut in both directions.

It would appear that the scientific evidence is not so black and white as dominant cultural voices would have us to believe. Similarly it also suggests that claiming science is diametrically opposed to the sort of timescale proposed by a literal reading of scripture can involve misrepresenting some of the evidence.


1/ N.T. Jeanson. 2013. Recent, Functionally Diverse Origin for Mitochondrial Genes from ~2700 Metazoan Species. Answers Research Journal. 6:467-501.

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