Sunday, July 25, 2010

Convergent Evolution and Intelligence

Measuring only about one-tenth of a millimeter in length, the female members of the wasp species Dicopomorpha echmepterygis are likely candidates for being the world’s smallest flying animal. Though accomplished fliers, these tiny parasitoid wasps are so minute that one could sit comfortably within the circumference of the period found at the end this sentence. Equally as versed in flight, but dramatically less petite than the insect aviators, were huge pterosaurs like Quetzalcoatlus. Though no human has ever laid eyes on a living specimen, fossil evidence clearly shows that some of these masters of the sky boasted wingspans well in access of thirty feet. In addition to the huge variety of aeronautically inclined insects and reptiles that have been identified, mammals too have converged on the adaptation of winged locomotion; mammals of the order Chiroptera have taken to the sky as moth hunting bats.

Like the adaptation of flight, eyes too have independently evolved in a number of different animal taxa. From the photoreceptive eyespots of a flatworm to the sharply focusing lenses of a great horned owl, eyes have arisen at least forty different times during the Earth’s biological history. ‘Convergent evolution’ is the phrase science uses to describe the common adaptations shared between different lineages of animals. For example, a case for convergent evolution could be made for the possum’s opposable thumb, which may very well represent an adaptation for improved grip; but, this enhanced grasping ability is hardly an indicator of a hereditary tie to primates. Rather than having been passed through genetic transmission from parent to offspring, the opposable thumb simply has an analogous structure and function for both possums and primates. So, just as flight isn’t unique to birds, the opposable thumb isn’t unique to primates.

If not opposable thumbs, is there a trait that is unique to primates? More to the point, is there a trait that is unique to the variety of apes called Homo sapiens? Perhaps intelligence is unique?

Maybe not as unique as we’d like to think:
de Waal, F., & Ferrari, P. (2010). Towards a bottom-up perspective on animal and human cognition Trends in Cognitive Sciences, 14 (5), 201-207 DOI: 10.1016/j.tics.2010.03.003

Monday, July 19, 2010

Tsunamis Hit Florida - Not!

I’ve been told that there is a rumor going around about methane gas bubbles causing a tsunami...

From Florida Department of Environmental Protection:

“Tsunamis are unlikely to occur as a result of the Deepwater Horizon incident. These rumors involve the naturally occurring methane beneath the seafloor in the Macondo Discovery, which is the petroleum reservoir into which the Deepwater Horizon production well was drilled. Scientists and engineers are aware of the physical and chemical behavior of methane in the earth and ocean, as well as during production of petroleum.

Science does not support the notion of a methane-induced tsunami resulting from Deepwater Horizon activities. However, while the possibility of an induced tsunami is extremely remote, DEP continues to take all concerns seriously and is consulting with experts in all related scientific fields.

View the following DEP fact sheet with more information about methane gas and the Deepwater Horizon incident: