Rocks and clocks help unravel the mysteries of ancient Earth

Aug 25, 2011
Rocks and clocks help unravel the mysteries of ancient Earth

(PhysOrg.com) -- Research into the dating techniques used to identify the origins of the living world has found the way in which fossils are used to calibrate the Earth’s evolutionary clock is of critical importance. The findings could help us better understand the gaps in the evolutionary timeline.

The study, led by academics at the University of Bristol and published in Biology Letters, analysed how the ‘’ and record align to determine how the Earth’s environment and living world have co-evolved.

The genes of living animals serve as timekeepers of the planet’s history and can be used to determine events that happened millions of years ago, from the origin of ancient life forms to the diverge between humans and chimps.

To estimate the pace at which the hands of the ‘molecular clock’ tick, it is necessary to 'calibrate' the clock by referencing the fossil record.

Historically, there have been controversial differences between the times predicted by the molecular clock and the fossil record. This is because the hands of the clock start ticking before novel life forms make their way into the rock record.  Furthermore, not everything is recorded - the rarity of animals and plants found in the further serves to create major gaps in the timeline.

The researchers found the way in which fossils are used to calibrate the molecular clock is of critical importance – a fact that has been frequently disregarded in most molecular clock studies attempting to provide a timeline for life’s history.

It has become commonplace for molecular biologists to second-guess how fossils can be used to calibrate the molecular clock. However, the findings confirm that this strategy can generate misleading scenarios about the origins of the living world.

Rachel Warnock, the lead researcher from the University’s School of Earth Sciences, said: “Without being able to place events of the past on a timeline, it becomes difficult to understand how the planet’s environment and the living world have co-evolved. Ultimately, the past provides a key to understanding the present and the future of the planet.”

The team of researchers from the University of Bristol and University College London adopted a cross-disciplinary approach combining the expertise of both molecular biologists and palaeontologists.

As we are approach five decades since the discovery of the molecular clock the team predict a more promising future for unravelling the past.

Rachel added: “If we want to piece together the crucial environmental events that have shaped the planet, it is vital that biologists and palaeontologists continue working together.

“Our next aim is to stimulate further collaboration between palaeontologists and biologists and continue building our vision of ’s mysterious past.

The paper, entitled ‘Exploring uncertainty in the calibration of the molecular clock’ by Rachel C. M. Warnock and Philip C. J. Donoghue from the University of Bristol and Ziheng Yang from University College London, is published today [24 Aug] in Biology Letters.

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Adiaphoron
not rated yet Aug 25, 2011
The dating game is such fun--using the unknown that is being measured (fossil age) to calibrate the gauge that is used to measure it (radiometric age). It would be nice to have a less circular approach to verifying age data.
kevinrtrs
1 / 5 (7) Aug 26, 2011
These guys are on a hiding to nothing.

There are so many unjustified assumptions that have to be made to date ANYTHING related to the past that one can usually laugh off the resultant ages that get derived from the physical artifacts.

Here they are assuming that the genetic "molecular clock" is in itself a valid way to measure time. How on earth are they going to calibrate it in a meaningful way since the fossils that lived in the distant past are not going to deliver their DNA for analysis. And if it did, then one would have to query whether those items could be millions of years old in the first place [because DNA just doesn't last that long, except in the evolutionary mythical world].
Evolution is the religion[mega-faith required] of the well-informed, highly educated since those who believe in a young [approx. 6000 years ] old earth are idiots and uneducated fools.
Robert_Wells
5 / 5 (1) Aug 27, 2011
the earth is 6kyo, god has mojo and controls everything, us evolutionists are just lying to get your panties in a bunch etc etc

now that we established that kevin will you please resign from physorg...or at least stick around after you post so we can have a discussion, instead of your hit and run trolling