Ardipithecus ramidus

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Ardipithecus ramidus

Posted: 16 Oct 2009 06:10 AM PDT

 

This week the Discovery Channel has been showing an amazing documentary on a new humanoid species Ardipithecus ramidus discovered in Ethiopia. The skeletal remains are dated to be 4.4 million years old. This is around 1 million years older than the Lucy skeletal remains. A cartoon sketching of this new species can be seen here.During the documentary, the commentators mentioned that the species was not fully human nor ape but a mosaic of the characteristics. Furthermore, unlike apes, Ardipithecus had small incisors and was bipedal (ambulated on two legs). Apes ambulate on all fours - called knuckle walking. Yet, humans are bipedal. The theory of this transition to a bipedal state is based on sex and food. Walking on two feet allowed the species to "gather." They could walking farther distances and CARRY items back with more efficiency. A male species that was better at gathering attracted more attention of the fertile females. Food for sex. Because of this, the longer incisors, that are used amongst apes to ward to competitors for the mating females, became shorter as this system of finding a mates changed. Physical dominance played lesser of a role and capabilities of food gathering was a greater edge in mating. Pure Darwinism. And because of this, the "if you don't use it, you loose it" concept allowed for shorter incisors.During the program, I began to think in terms of diet. It is known that humans lost the ability to breakdown uric acid by enzymatic means (uricase) millions of years ago. There is no clear cut reason why. However, my theory is the same as the "use it or loose it" scenario. What do I mean? Apes are basically vegetarians but they have been known to eat other smaller monkeys. Living amongst the trees entails a diet of leaves and fruits. As humans became bipedal, their gathering capabilities improved. Furthermore, the transition from gathering to "hunter and gather" dramatically changed their diet from the ape world. It would make more sense from a calorie economy standpoint to hunt large prey than to burn more energy during the day gathering low calorie vegetables, leaves, and seasonal fruit. Remember that human metabolism is based on storage and efficiency. Ancient hunters would have gotten "more bang for the buck" by killing large prey than gathering leaves and occasional fruit. For example, apes and grazing animals spend a large amount of the day chewing on leaves and grass in order to get enough calorie intake.This bring me back to uric acid. Unlike Ardipithecus ramidus, our brains are much larger. In fact, our brain uses 25% of the body's calorie requirements. A bigger brain means higher calories requirements. Thus, smarter humans had no choice but to hunt for animal prey. They exchanged a diet of plants and fruit for one of animal (protein and fat), seasonal fruit, and nuts. Higher calorie prey (animals) meant less time gathering and more time on innovation, clothing, shelter, art (cave drawing), language, city building, etc.Uric acid is derived from the metabolism of the purines called adenine, guanine, and inosine. These nucleotides are the building blocks of DNA and RNA along with the pyrimidines: thymine, cytosine, and uracil. Moreover, adenosine is also used for the production of adenosine triphosphate (ATP). ATP is cellular energy made in the mitochondria. It is true that protein consumption does lead to uric acid creation through the metabolism of animal protein (DNA and RNA). But, fructose also drives up the uric acid production by causing enhanced breakdown of ATP. How does this work? In biochemical terms, Fructose is converted to Fructose 1-phosphate by ATP donating a phosphate bond by means of the enzyme Fructokinase. This is the same enzyme that I mentioned in my previous entry earlier this week regarding my cruise ship experience and sugar intake.In terms of high uric acid levels and modern humans, high fructose consumption seems to be a greater culprit than protein intake. And as many know, high uric acid levels can lead to gout and kidney stones. But moreover, the recent science reveals that high uric acid levels contribute to cardiac disease. Reflecting on ancient humans,they diverted from a heavy plant, fruit based diet to more animal protein (saturated fats and protein). Therefore, it is my belief that we lost the enzyme to breakdown uric acid (known as uricase) as the requirement was low for the enzyme itself (lower fructose intake). This only strengthens the concept that the human diet should be lower in fructose, omega 6, carbohydrates and higher in saturated fats. On the other hand, modern humans have traded their hunting spear for the shopping cart. I am all fine with this, as I have no interest in hunting for alligators in Florida. The problem is that the fructose load with the modern Western diet is filled with juices, high fructose corn syrup, and excessive amounts of sugar (colas, cookies, etc). Sugar is 50% fructose. For some the fruit intake is also to excessive. We modern humans are not designed for high fructose intake. I seems that Ardipithecus ramidus was not either based on her anatomy.So literally, high fructose consumption is for the birds - namely the parrots. They have the URICASE enzyme - we don't.Check the Discovery website for times of showing for Disovering Ardi.1) Johnson RJ, Segal MS, Sautin Y, Nakagawa T, Feig DI, Kang DH, Gersch MS, Benner S, Sánchez-Lozada LG: Potential role of sugar (fructose) in the epidemic of hypertension, obesity and the metabolic syndrome, diabetes, kidney disease, and cardiovascular disease. Am J Clin Nutr. 2007 Oct;86(4):899-906