Scientists have finally joined the long list of hippies, teenage girls and vegetarians who have come to the conclusion that, since dolphinkind rates among the smartest crews ever to clutter God’s bluish-green Earth, they are deserving of a greater measure of our respect.
“They are the second most encephalized beings on the planet,” Lori Marino, neuroanatomist at Emory University, Atlanta, GA, told ScienceNOW.
Found among Marino’s research is a fascinating paper on the convergence of behaviours between primates and toothed whales, which includes a thought-provoking discussion of the neuroanatomy of dolphins.
Primates and dolphins share a number of abilities — in sociality, problem solving, and self recognition — despite embarking on separate evolutionary paths around the time the Spinosaurus went the way of the dodo 95 million years ago.
But what is especially surprising about this convergence in behaviour is the divergence in brain structure betwen the groups.
The brains of great apes — and especially humans — show elongation in the lengthwise axis, especially in the region of the frontal lobes (above the eyes, dimwit). Experiments involving human individuals whose frontal regions have been (more or less deliberately) damaged have established the importance of this area in executive function.
And yet among the toothed whales, this region is almost non-exisent; instead, the cetacean brain exhibits expansion across the lateral axis.
Quite literally, they have more between the ears than we do.
But wait: there’s more. Detailed sections of the dolphin brain have revealed the presence of a layer of tissue that is completely absent in primates — a paralimbic cortex whose function is “largely unknown”.
This raises the intriguing possibility that dolphins, with whom we seem to share so much, quite literally cannot percieve the world in the same way we do.
Nevertheless, our neuroanatomical differences notwithstanding, philosopher Thomas White of Loyola Marymount University in Redondo Beach, CA, is bold enough to call dolphins “non-human persons”.
[Dolphins are] alive, aware of their environment, have emotions … seem to have personalities, exhibit self-controlled behavior, and treat others appropriately, even ethically
Provoking the world’s complement of philosophers, White said: “When it comes to what defines a person, dolphins fit the bill.”
Pouring out the measure of scorn traditionally required by each new announcement from the scientific community, Dr. Jacopo Annese, neuronatomist at the University of California, San Diego, scowled across the AAAS table: “We don’t know, even in humans, what is the relationship between brain structure and function, let alone intelligence.”