Archive for the ‘History of Life’ Category

Design of Bird Brains for Long Migrations

Monday, January 26th, 2009

Design of Bird Brains for Long Migrations

by Hugh Ross, Ph.D

Photo of Hugh RossMany migrating birds fly all night long. Some fly nonstop across huge ecological barriers like the Gulf of Mexico. For decades, biologists have wondered how these creatures can survive the severe sleep deprivation brought about by such migration habits. Now, a team of American biologists and neuroscientists appear to have found an answer that reveals a previously unknown level of life design and design convergence.

During the research, seven Swainson’s thrushes–birds that remain active all day and fly all night during their migration–were put into a cage where the scientists induced artificial sunrises and sunsets that mimic the migration season. For each of the birds they implanted electrodes to monitor brain activity.

The team discovered that during the simulated daylight hours the animals took mini-naps with one eye shut and the other open. The electrodes revealed that one hemisphere in each bird’s brain manifested electrical patterns resembling nighttime sleep while the other showed patterns indicative of daytime wakefulness.1 The research team concluded that the thrushes rested their brains, one half at a time, in order to catch up on sleep.

In order to remain ever vigilant against attacks these birds do not relax both brain hemispheres at the same time. Their nighttime migrations limit the risk of exposure to predators and avoid overheating.

To date, neither biologists nor neuroscientists understand how it is that the brains of migrating birds let one hemisphere sleep while the other is awake and allow the two hemispheres to periodically trade their sleeping and waking modes. Yet, there is no question that such a capacity is an amazing design feature. The idea that it could spontaneously evolve defies a naturalistic explanation.

This outstanding brain design is not unique to birds taking long migration flights. Scientists have observed the same kind of brain behavior in several marine mammals such as dolphins and whales. Thus, this particular design feature provides yet one more example of what evolutionary biologists term “convergent evolution.” A more accurate label would be a “repeated design outcome.” Two species (thrushes and whales) that are completely unrelated on any Darwinian evolutionary trees exhibit an identical and extraordinary brain characteristic. The only reasonable explanation for such an outcome is a supernatural, super-intelligent Creator repeating an optimal design. This explanation is all the more compelling in the context of hundreds of other examples of purposeful convergence for species unrelated in an evolutionary context.

  1. T. Fuchs et al., “Daytime Micro-Naps in a Nocturnal Migrant: an EEG Analysis,” Biology Letters (November 5, 2008): 10.1098/rsbi.2008.0405.

Confirming the Moon’s Vital Role

Monday, November 10th, 2008

by Hugh Ross

Photo of Hugh RossBack in 1993, a research team led by French astronomer Jacques Laskar proved analytically that the tilt of Earth’s rotation axis is stabilized over long time periods thanks to Earth being orbited by a single moon whose mass is a substantial fraction of Earth’s.1 (See here and here.) Laskar’s team showed that with the Moon Earth’s rotation axis tilt varies over many millions of years between 22.0 and 24.6 degrees. Without the Moon, Earth’s rotation axis tilt would vary between 0 and 85 degrees.

Variations in Earth’s rotation axis tilt of much more than a couple of degrees would generate climate changes catastrophic for advanced life. Consequently, the Moon’s amazingly unique features (for example, the Moon-Earth mass ratio is fifty times greater than for any other known moon-planet system) are crucial for the existence of advanced life. These highly fine-tuned features form one of the cornerstones of the evidence for a supernatural, super-intelligent Creator.

In the context of evidence for design, astronomers, for some time, have desired a more rigorous confirmation of the Laskar team’s research results. Now, such a confirmation has arrived.2 This new study uses realistic planetary orbits and takes into account both solar and planetary torques exerted on the Moon and the Earth. The calculations extend from two billion years in the past to two billion years into the future.

The new analysis finds that short-term variations in the tilt of a moonless Earth’s rotation axis are somewhat less than what Laskar’s team calculated. The long-term variations (timescale in excess of 100 million years) are just as prominent. Therefore, this particular evidence for the design of the Earth-Moon system for the specific benefit of advanced life has now been more rigorously established.

  1. Jacques Laskar and P. Robutel, “The Chaotic Obliquity of the Planets,” Nature 361 (February 18, 1993): 608-12; Jacques Laskar, F. Joutel, and P. Robutel, “Stabilization of the Earth’s Obliquity by the Moon,” Nature 361 (February 18, 1993): 615-17.

  2. Jason Barnes, Jack J. Lissauer, and John E. Chambers, “Long-Term Obliquity Evolution of Reimagined Moonless Earths,” Astrobiology 8 (April 2008): 373.