I just found this presented as "a fact"... Does any one know it it's correct? At least it's funny...
"Right whales have the biggest testicles, weighing up to a ton - and the tiniest brain to body mass ratio."
...a...
Well, I went a-looking for data on the brain to body mass ratio on the Right Whale and happened upon some things for your consideration:
"One might note that the polygon connecting the outer limits of the data points shows the elephant and blue whale at the extreme points. Although elephants are generally considered to be fairly intelligent, there is no evidence that they are more intelligent than humans. Therefore, interpretation of this figure requires a methodology for establishing the relative brain capacities of the different species independently of body size. " From
Talk:Brain-to-body mass ratio - Wikipedia, the free encyclopedia
However, the noted citation for this quotation on the Wiki page is now missing, not to imply it was never there, but it is certainly no longer where it was linked to have been. It does, regardless, raise the question of the relevance in this age of the idea of being "bird brained", for example. The entire brain of the bird has been renamed by the Cornell University, due to our current understanding of ornith intelligence. Take one look at the original names, and you'll understand this recent shift; to be "bird brained" no longer implies low I.Q.. I say this to imply that it is possible that the data may skew ones conception of the Right Whale's intelligence if indeed true.
The above also brings about the same issue as to be found with the question of the nether region- the Blue Whale is still the largest animal on Earth, therefore brain to body mass ratios should be, as stated above, extreme in nature. But, as also raised as an issue above, the way in which the data is collected (whether it is based on actual necropsy or statistical analysis remains unclear) may skew data in one way or another.
According to a neo-Wiki, "Whales have the largest brain of any animal. A typical sperm whale brain weighs about 7.8 kg, whereas a typical human brain weighs about 1.5 kg. While it may seem that this would indicate that five times greater intelligence, in mammals brain size is in approximate ratio to body size, and most of the extra capacity is used to manage the larger body." From
Whale - New World Encyclopedia
But remember that weight and mass equate to two different subjects, as weight changes as forces such as gravity impact an object. Your body weight differs from that upon Earth as it does upon the Moon, for one example. Mass is a constant, weight is not, as weight is the acceleration of gravity times mass.
On the same page linked above, "A more precise indicator is the brain-body ratio: the size of the brain compared to body mass. Here humans have a decisive advantage. A human brain comprises about 2 percent of the human body mass, while the sperm whale's brain comprises only 0.02 percent of its body mass. A cow's brain is four times as large as a whale's on this measurement. On the other hand, a large proportion of a whale's body mass is blubber, which requires no brainpower, and this distorts the ratio somewhat. Nevertheless, it is clear that brain size is not a decisive criterion. Hummingbirds have an even higher brain-to-body ratio than humans."
Certainly makes one wonder
According to
http://www.int-res.com/articles/meps2003/264/m264p123.pdf, "...where M is the mass of a right whale in kg. The term
in brackets is after Kleiber (1975) and the first term converts
Kleiber’s expression from kcal d–1 to W (or J s–1).
The assimilation efficiency and body mass are assumed
to be 0.80 (Lockyer 1981) and 40 000 kg (Kenney &
Winn 1986), respectively; therefore, BMR = 0.96 × 104
W..." So there is your Right Whale mass for any calculations you may desire to make [70M to the 0.75 power, Kleiber (1975)]. Plus, what scientifically-oriented diver does not love a good Northern Atlantic Right Whale data sheet? =D Please note that you should read the work as I could not quote the equation as shown in the paper itself, but it is fully defined in the paper. The formula to identify brain to body mass ratio is as follows: "Ew(brain) = 0.12w(body)2 / 3, though for some classes of animals the power is 3/4 rather than 2/3" From
http://en.wikipedia.org/wiki/Brain-to-body_mass_ratio and citing "Allometry".
http://weber.ucsd.edu/~jmoore/courses/allometry/allometry.html. Retrieved 2008-09-15. I apologize for not having the actual brain size for you- that will most likely require a library trip.
I did happen upon the following as well, and may interest some of you in the diving realm ;D
"Does Diving Limit the Brain Size in Cetaceans?
Source: Marino, L., Sol, D., Toren, K., and Lefebvre, L. 2006. Does diving limit brain size in cetaceans? Marine Mammal Science 22(2): 413-425.
Large brains have a high metabolic and oxygenation cost. The oxygen demands during diving may pose a limitation on the brain size of marine mammals, which is a hypothesis called the “dive constraint hypothesis.” This hypothesis predicts that relative brain size would be negatively correlated with maximum dive time. Although it has been tested previously, the results have not been conclusive.
This study examined 23 species of cetaceans for their relative brain size, body size, and maximum dive duration. Several measures of brain size were used: 1) brain to body size ratio; 2) Jerson encephalization quotient; 3) Martin encephalization quotient; 4) and 5) log transformations of 2) and 3); and residual brain size.
The maximum dive duration was negatively correlated with all of the measures of brain size, except the residual brain size, which showed no correlation. The residual brain size was the only measure used that did not take body size into account at all.
A multiple regression was performed including body and brain size; the result was that the only significant predictor of dive time was body size. These results lead to the conclusion that brain size does not limit dive time. Instead, maximum dive time seems to be determined by body size and muscle mass. " From
http://www.acsonline.org/issues/researchRpts/Research0605.html
And, you can also check here:
http://news.softpedia.com/news/Whale-Brain-Surprisingly-Similar-to-Human-Brain-41158.shtml
Good articles
