Faster metabolism enabled larger brains?

_{Denyse O'Leary

May 11, 2016

Human evolution, Intelligent Design, News}

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Adjusted for body size, on a daily basis humans consume 400 more calories than chimpanzees/Raimee, Fotolia

Researchers have found humans have a higher metabolism rate than closely related primates, which enabled humans to evolve larger brains.

The study found that, adjusted for body size, on a daily basis humans consume 400 more calories than chimpanzees and bonobos (closely related to chimps), 635 more calories than gorillas and 820 more calories than orangutans.

…

The study confirmed the researchers’ hypothesis that humans evolved a faster metabolism and larger energy budget to accommodate larger brains, which consume more calories. The higher metabolism also supports having more offspring and a longer lifespan. More. Paper. (paywall) – Herman Pontzer, Mary H. Brown, David A. Raichlen, Holly Dunsworth, Brian Hare, Kara Walker, Amy Luke, Lara R. Dugas, Ramon Durazo-Arvizu, Dale Schoeller, Jacob Plange-Rhule, Pascal Bovet, Terrence E. Forrester, Estelle V. Lambert, Melissa Emery Thompson, Robert W. Shumaker, Stephen R. Ross. Metabolic acceleration and the evolution of human brain size and life history. Nature, 2016; DOI: 10.1038/nature17654

Something about this explanation doesn’t quite work. Brains deteriorate quickly when deprived of essentials. The body can’t just “evolve” a higher metabolism to accommodate a more demanding brain. The whole thing would need to be a co-ordinated program.

And for what purpose? A primate can feed and protect itself and reproduce without being exceptionally intelligent.

Also, is it true that larger brains promote a faster metabolism in principle? What about whales?

Is it true that a fast metabolism supports having more offspring? Reptilians whose metabolism can drop to very low levels certainly produce more offspring than primates.

Is it true that a fast metabolism is associated with longevity? What about hamsters?

Reader insight into these questions is appreciated.

See also: The simple steps that made us human? The slide show ends with: “Because big questions need answering.” Yes, but one could be a bit more particular about the depth of the answers. These answers seem addressed to people who have no serious questions.

and

Human origins: The war of trivial explanations

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Comments

of note:
Of Life's Laws And Unity - May 11, 2016 Excerpt: Life obeys certain allometric scaling laws that seem to reveal a sort of overarching design principle at work. We don't know what this principle is, although it's probably related to optimization: What's the best shape for the least amount of energy consumption? A famous allometric law is known as Kleiber's Law, where the metabolic rate of an animal grows as its mass to the 3/4 power. (The metabolic rate can be measured in terms of the rate at which an animal consumes oxygen, for example.) Although there are small variations (due to motion, disease, aging), the relation holds over a wide range of masses. (There are disputes for very small animals without a circulatory system.) Geoffrey West, Brian Enquist and James Brown proposed a model based on blood flow to explain this and a few other general allometric scaling laws with body weight observed in animals (for a review paper see this): Apart from Kleiber's Law mentioned above, life span scales as 1/4 power (so take two square roots of the mass), and heart rate as -1/4 power. Put together, these two laws explain why all species have a similar amount of heartbeats, 1.5 billion, over their life spans. Pause for amazement. The laws are not absolutely precise but do indicate a common trend across an enormous variety of living creatures. On Monday night, I was on a panel on Complexity with Geoffrey West at the New York Academy of Sciences. At some point, I asked West whether alien life, if it exists, would follow the same sort of unifying allometric laws. With a twinkle in his eye, West replied, a big smile on his face: "Well, I can only speculate here, but it seems plausible that this sort of design principle for life does have universal characteristics." It would be amazing if life as we don't know it is, after all, life as we do know it. http://www.npr.org/sections/13.7/2016/05/11/477607869/of-life-s-laws-and-unity
bornagain77_{May 12, 2016
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Is having bigger brains a proven fact as related to bigger intelligence or is it a presumption or bias before thoughtful investigation?? Is the soul been disproven? If not then its a option for the place of intelligence and brain size is not relevant. By the way don't boys have bigger brains then girls in weighing them? Does this mean something to the evo crowd? Why so quiet about that?Robert Byers_{May 11, 2016
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correction to 'Scaling of Brain Metabolism' excerpt:
General Discussion Excerpt: ,,It should be underlined that both CBF and CMR scale with brain volume with the exponent about 1/6 which is significantly different from the exponent 1/4 relating whole body resting specific metabolism with body volume [1], [2], [3].
Further notes as to the constancy of the Brain's metabolic activity
Appraising the brain's energy budget: Excerpt: In the average adult human, the brain represents about 2% of the body weight. Remarkably, despite its relatively small size, the brain accounts for about 20% of the oxygen and, hence, calories consumed by the body. This high rate of metabolism is remarkably constant despite widely varying mental and motoric activity. The metabolic activity of the brain is remarkably constant over time. http://www.pnas.org/content/99/16/10237.full THE EFFECT OF MENTAL ARITHMETIC ON CEREBRAL CIRCULATION AND METABOLISM Excerpt: Although Lennox considered the performance of mental arithmetic as "mental work", it is not immediately apparent what the nature of that work in the physical sense might be if, indeed, there be any. If no work or energy transformation is involved in the process of thought, then it is not surprising that cerebral oxygen consumption is unaltered during mental arithmetic. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC438861/pdf/jcinvest00624-0127.pdf Does Thinking Really Hard Burn More Calories? - By Ferris Jabr - July 2012 Excerpt: Unlike physical exercise, mental workouts probably do not demand significantly more energy than usual. Believing we have drained our brains, however, may be enough to induce weariness,,, Although the average adult human brain weighs about 1.4 kilograms, only 2 percent of total body weight, it demands 20 percent of our resting metabolic rate (RMR)—the total amount of energy our bodies expend in one very lazy day of no activity.,,, —Resting metabolic rate: 1300 kilocalories, or kcal, the kind used in nutrition —1,300 kcal over 24 hours = 54.16 kcal per hour = 15.04 gram calories per second —15.04 gram calories/sec = 62.93 joules/sec = about 63 watts —20 percent of 63 watts = 12.6 watts So a typical adult human brain runs on around 12 watts—a fifth of the power required by a standard 60 watt lightbulb. Compared with most other organs, the brain is greedy; pitted against man-made electronics, it is astoundingly efficient. http://www.scientificamerican.com/article.cfm?id=thinking-hard-calories
bornagain77_{May 11, 2016
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The abject failure of Natural Selection on two levels of physical reality – video (2016) (princess and the pea paradox & quarter power scaling) https://www.facebook.com/philip.cunningham.73/videos/vb.100000088262100/1135217836491148/?type=2&theater
The reason why ’4-Dimensional’ quarter power scaling laws are impossible for Darwinism to explain is that Natural Selection operates at the 3-Dimensional level of the organism and the ’4-Dimensional’ quarter power scaling law are simply ‘invisible’ to natural selection. The reason why 4-Dimensional things are, for all practical purposes, completely invisible to 3-Dimensional things is best illustrated by ‘flatland’:
Dr Quantum - Flatland - video https://www.youtube.com/watch?v=BWyTxCsIXE4
Though Jerry Fodor and Massimo Piatelli-Palmarini rightly find it inexplicable for 'random' Natural Selection to be the rational explanation for the invariant scaling of the physiology, metabolism, and anatomy, of living things to four-dimensional parameters, they do not seem to fully realize the implications this 'four dimensional scaling' of living things presents. This 4-D scaling is something we should rightly expect from a Intelligent Design perspective. This is because Intelligent Design holds that ‘higher dimensional transcendent information’ is more foundational to life, and even to the universe itself, than either matter or energy are. This higher dimensional 'expectation' for life, from a Intelligent Design perspective, is directly opposed to the expectation of the Darwinian framework, which holds that information, and indeed even the essence of life itself, is merely an 'emergent' property of the 3-D material realm.
Molecular Biology - 19th Century Materialism meets 21st Century Quantum Mechanics – video https://www.facebook.com/philip.cunningham.73/videos/vb.100000088262100/1141908409155424/?type=2&theater Scientific evidence that we do indeed have an eternal soul - video https://www.facebook.com/philip.cunningham.73/videos/vb.100000088262100/1116313858381546/?type=2&theater
A few more notes:
“A number of hominid crania are known from sites in eastern and southern Africa in the 400- to 200-thousand-year range, but none of them looks like a close antecedent of the anatomically distinctive Homo sapiens…Even allowing for the poor record we have of our close extinct kin, Homo sapiens appears as distinctive and unprecedented…there is certainly no evidence to support the notion that we gradually became who we inherently are over an extended period, in either the physical or the intellectual sense.” Dr. Ian Tattersall: – paleoanthropologist – emeritus curator of the American Museum of Natural History – (Masters of the Planet, 2012) If Modern Humans Are So Smart, Why Are Our Brains Shrinking? - January 20, 2011 Excerpt: John Hawks is in the middle of explaining his research on human evolution when he drops a bombshell. Running down a list of changes that have occurred in our skeleton and skull since the Stone Age, the University of Wisconsin anthropologist nonchalantly adds, “And it’s also clear the brain has been shrinking.” “Shrinking?” I ask. “I thought it was getting larger.” The whole ascent-of-man thing.,,, He rattles off some dismaying numbers: Over the past 20,000 years, the average volume of the human male brain has decreased from 1,500 cubic centimeters to 1,350 cc, losing a chunk the size of a tennis ball. The female brain has shrunk by about the same proportion. “I’d call that major downsizing in an evolutionary eyeblink,” he says. “This happened in China, Europe, Africa—everywhere we look.” http://discovermagazine.com/2010/sep/25-modern-humans-smart-why-brain-shrinking Scientists Discover Proof That Humanity Is Getting Dumber, Smaller And Weaker By Michael Snyder, on April 29th, 2014 Excerpt: An earlier study by Cambridge University found that mankind is shrinking in size significantly. Experts say humans are past their peak and that modern-day people are 10 percent smaller and shorter than their hunter-gatherer ancestors. And if that’s not depressing enough, our brains are also smaller. The findings reverse perceived wisdom that humans have grown taller and larger, a belief which has grown from data on more recent physical development. The decline, said scientists, has happened over the past 10,000 years. http://thetruthwins.com/archives/scientists-discover-proof-that-humanity-is-getting-dumber-smaller-and-weaker Cro Magnon skull shows that our brains have shrunk - Mar 15, 2010 by Lisa Zyga Excerpt: Using new technology, researchers have produced a replica of the 28,000-year-old brain and found that it is about 15-20% larger than our brains. http://phys.org/news187877156.html “Neanderthals are known for their large cranial capacity, which at 1600cc is larger on average than modern humans.” http://en.wikipedia.org/wiki/Neanderthal#Anatomy
bornagain77_{May 11, 2016
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A few notes:
Energy Efficiency Doesn’t Explain Human Walking? Sept. 17, 2012 Excerpt: Why hominids evolved upright walking is one of the biggest questions in human evolution. One school of thought suggests that bipedalism was the most energetically efficient way for our ancestors to travel as grasslands expanded and forests shrank across Africa some five million to seven million years ago. A new study in the Journal of Human Evolution challenges that claim, concluding that the efficiency of human walking and running is not so different from other mammals. Physiologists Lewis Halsey of the University of Roehampton in England and Craig White of the University of Queensland in Australia compared the efficiency of human locomotion to that of 80 species of mammals, including monkeys, rodents, horses, bears and elephants.,,, To evaluate whether energy efficiency played a role in the evolution of upright walking, Halsey and White note that hominids should be compared to their closest relatives. For example, if human walking is more efficient than chimpanzee walking than you would expect based on chance alone, then it lends support to the energy-efficiency explanation. But that’s not what the researchers found. In fact, the energetic differences between humans and chimpanzees are smaller than the differences between very closely related species that share the same type of locomotion, such as red deer versus reindeer or African dogs versus Arctic foxes. In some cases, even different species within the same genus, such as different types of chipmunks, have greater variation in their walking efficiencies than humans and chimps do. http://blogs.smithsonianmag.com/hominids/2012/09/energy-efficiency-doesnt-explain-human-walking/ Scaling of Brain Metabolism with a Fixed Energy Budget per Neuron: Excerpt: This suggests that the energy budget of the whole brain per neuron is fixed across species and brain sizes, http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0017514 Scaling of Brain Metabolism and Blood Flow in Relation to Capillary and Neural Scaling - 2011 Excerpt: Brain is one of the most energy demanding organs in mammals, and its total metabolic rate scales with brain volume raised to a power of around 5/6. This value is significantly higher than the more common exponent 3/4 (4- dimensional Quarter Power Scaling) relating whole body resting metabolism with body mass and several other physiological variables in animals and plants.,,, Moreover, cerebral metabolic, hemodynamic, and microvascular variables scale with allometric exponents that are simple multiples of 1/6, rather than 1/4, which suggests that brain metabolism is more similar to the metabolism of aerobic than resting body. Relation of these findings to brain functional imaging studies involving the link between cerebral metabolism and blood flow is also discussed.,, General Discussion Excerpt: ,,It should be underlined that both CBF and CMR scale with brain volume with the exponent about 1/4 which is significantly different from the exponent 1/4 relating whole body resting specific metabolism with body volume [1], [2], [3]. Instead, the cerebral exponent 1/6 is closer to an exponent,, characterizing maximal body specific metabolic rate and specific cardiac output in strenuous exercise [43], [44]. In this sense, the brain metabolism and its hemodynamics resemble more the metabolism and circulation of exercised muscles than other resting organs, which is in line with the empirical evidence that brain is an energy expensive organ [10], [17], [18]. This may also suggest that there exists a common plan for the design of microcirculatory system in different parts of the mammalian body that uses the same optimization principles [45].,, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3203885/
The preceding experiments are very unexpected for materialists since materialists hold that 'mind' is merely a 'emergent property' of the material brain. But why should 'thought' which is presupposed to be result of, and subservient to, the material processes of the brain constrain the material brain to operate at such a constant and optimal metabolic rate whereas the rest of body fluctuates in its metabolic activity with physical activity? The most parsimonious explanation for such a optimal constraint on the brain's metabolic activity is that the material brain was designed, first and foremost, to house the 'mind' and to give the mind the most favorable metabolic environment at all times. Moreover the brain, in terms of its 'almost unbelievable' complexity, is shown to have more switches than all the computers on earth put together, and yet the brain consumes far less energy than a computer does, which strongly suggests to me, because of Landauer's principle (heat cost of erasing information), that the information of the mind (memories) must be stored on a 'spiritual' level rather than on a material level.
Are computers conscious? https://docs.google.com/document/d/1aLRzzzDXZoADkoOIubQECLTiD2ceAhzk_0XzSjds2r4/edit?usp=sharing
Moreover, quarter power scaling by itself very antagonistic to Darwinian claims
The predominance of quarter-power (4-D) scaling in biology Excerpt: Many fundamental characteristics of organisms scale with body size as power laws of the form: Y = Yo M^b, where Y is some characteristic such as metabolic rate, stride length or life span, Yo is a normalization constant, M is body mass and b is the allometric scaling exponent. A longstanding puzzle in biology is why the exponent b is usually some simple multiple of 1/4 (4-Dimensional scaling) rather than a multiple of 1/3, as would be expected from Euclidean (3-Dimensional) scaling. http://www.nceas.ucsb.edu/~drewa/pubs/savage_v_2004_f18_257.pdf 4-Dimensional Quarter Power Scaling In Biology – video https://www.youtube.com/watch?v=uEB4p9qbliE Post-Darwinist - Denyse O'Leary - Dec. 2010 Excerpt: They quote West et al. (1999), “Although living things occupy a three-dimensional space, their internal physiology and anatomy operate as if they were four-dimensional. Quarter-power scaling laws are perhaps as universal and as uniquely biological as the biochemical pathways of metabolism, the structure and function of the genetic code and the process of natural selection." They comment, "In the words of these authors, natural selection has exploited variations on this fractal theme to produce the incredible variety of biological form and function', but there were severe geometric and physical constraints on metabolic processes." "The conclusion here is inescapable, that the driving force for these invariant scaling laws cannot have been natural selection. It's inconceivable that so many different organisms, spanning different kingdoms and phyla, may have blindly 'tried' all sorts of power laws and that only those that have by chance 'discovered' the one-quarter power law reproduced and thrived." Quotations from Jerry Fodor and Massimo Piatelli-Palmarini, What Darwin Got Wrong (London: Profile Books, 2010), p. 78-79. https://uncommondescent.com/evolution/16037/
Here is, what a Darwinist termed, a ‘horrendously complex’ metabolic pathway chart (which operates as if it were ’4-Dimensional):
ExPASy - Biochemical Pathways - interactive schematic http://biochemical-pathways.com/#/map/1
To say Darwinian explanations fall short of explaining metabolic pathways is to insult the term 'fall short'bornagain77_{May 11, 2016
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