ANTHROPOCURIOUS
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Why men’s noses seem to be bigger than women’s? The University of Iowa has the answer
Researches from this university, published an article in 2013 which explains the reason about this strange fact and they realized that the key is on our physiology.
Men have a 10% larger nose just because they have more lean muscle mass and this means that they need more oxygen in order to maintain the muscle tissue and also to guarantee a correctly growth. Furthermore, it is believed that the size difference comes from different buildings of the sexes. This size’s difference shows up when the puberty starts (at the age of 11), males begin to grow more lean muscle mass and females more fat mass and from this moment, males will require more oxygen.
The researches also underline the relationship between the nose and the body size to explain why our noses are smaller than our ancestors’, such as Neanderthals. This is because our ancestors had more lean muscle mass than us and they had bigger rib cages and lungs therefore they needed more oxygen to maintain .
Do you think that this an advantage? If you want to read more about this, you just have to click in the link below:
http://www.sciencedaily.com/releases/2013/11/131118160045.htm
Why were Victorian Women deformed?
“To suffer for Beauty” is a common saying that can be heard until nowadays, but long time ago it do have more sense. We are talking about the Victorian age, when the ideal of how woman´s body should look like leaded to deformation of their body shape. These alterations were due to corseting of the waist to make an hourglass figure, which alters the skeleton deforming the ribs and misaligning the spine. Moreover, the natural position of internal organs is also changed: both the liver and the stomach were forced downward!
Amazingly, some women lived long and healthy lives and, in many cases, even longer than the average. Because of that, the anthropologist Rebecca Gibson of American University affirms that the view of corseting as having created short and painful lives is anachronistic.
Corset-wearing was common in the 18th and 19th centuries and it had 2 aims: to change women natural body shape and to transform it into a more ideal form, characteristic of civilized population. Although most of us think of women wearing a corset when being adults, woman wore them since their childhood and even when being pregnant special corsets were worn.
It is clear that the long-term use of corset causes changes in women’s skeletons and, looking at the physical effects it has, we can think about it as a painful device. To investigate those skeletal changes, Gibson studied remains dating to 1700-1900 AD held at the Musée de l’Homme at the Museum National d’Histoire Naturelle in Paris and at the Centre for Human Bioarchaeology at the Museum of London.
The skeletons had their ribs deformed, adopting and ‘S’ shape and vertebral spines were misaligned due to the pressure. As a consequence of wearing corset, measures that nowadays can be unbelievable were achieved, being the average waist size of those women something near 56 cm!!
Why modern humans have chins?
Modern Humans are the only primates that have chins, which can be a characteristic difference when recognizing them in the fossil record. Chins seem to be the result from an evolutionary adaptation involving face size and shape, according to a team of anthropologists at the University of Iowa.
This was demonstrated by facial and cranial biomechanical analyses with nearly 40 people. The results suggested that mechanical forces, including chewing, are incapable of producing the resistance needed to create that prominence in the lower mandible.
In contrast to what previously thought, chin seems to be appeared as a result of geometrical compensation: during evolution, apes´ faces have decreased in size and chin emerged as an adaptation to balance that change in shape.
We have no evidence of chins being closely related with mechanical function. As a consequence, the human chin is believed to be a result of our lifestyle change focusing in migratory movements.
The scientists think that anatomically modern humans evolved from hunter groups that were isolated from each other to bigger groups that formed social networks. Behavioral patterns changed among these groups and males in particular became more tranquil, which was tied to reduced testosterone levels. Due to those hormonal changes, the male craniofacial region was altered.
To sum up, the study concludes that chin prominence is unrelated to mechanical function of the lower jaw and that probably has more to do with migratory movements during evolution.
Have apes invented opera singing?
It is known that apes are very similar to humans both physically and genetically, but it is also true that our behavior is not as different as we may think. Even so, could you imagine a gibbon singing and, moreover, singing opera?
Although this idea of opera singing apes sounds quite unbelievable, a study published in the American Journal of Physical Anthropologydiscovered that that gibbons use the same vocal techniques as professional soprano singers. The research, led by Dr Takeshi Nishimura from the Primate Research Institute at Kyoto University (Japan), was based on the particular sounds that these apes use to communicate with each other.
The sounds that gibbon ́s produce are interesting due to de unique techniques they have to pursue, which are acoustically different to the ones they the rest of apes use. While studying those techniques under the influence of helium gas, the recorded results reveal that there is a physiological similarity to human voices. As helium increases sound velocity and resonance frequencies, the sounds of gibbons under its effects revealed that they are capable to consciously manipulate their vocal cords and tract. This shows that gibbons use the same process for producing speech as humans.
The ability that gibbons show to ,with minimal effort, adopt complex vocal techniques is only shown in humans among professional soprano singers, which leads us consider gibbons the "soprano singing apes". This discovery suggests that humans share the biological fundamentals of vocalization with other primates, but differ from the rest in more sophisticated modifications related with speech.
Listen to the Hominid Rap and learn about the fossils of our ancestors!
The Hominid Rap
Cro-Magnon 1
Cro-Magnon 1 is a middle-aged, male skeleton of one of the first modern human fossils ever found, at Cro-Magnon, France in 1868. Scientists estimate his age at death at less than 50 years old. Except for the teeth, his skull is complete, though the bones in his face are noticeably pitted from a fungal infection
Identified genes that influence in being right-handed or left-handed
Scientists at the Universities of Oxford, St Andrews, Bristol and the Max Plank Institute in Nijmegen, the Netherlands, found correlations between handedness and a network of genes involved in establishing left-right asymmetry in developing embryos.
An early embryo moves on from being a round ball to a symmetrical organism with left and right sides. The genes involved in this process seem to be involved in being left-handed or right-handed, but even more, they seem to help establish left-right differences in the brain.
The statistically most significant variant with handedness is located in the gene PCSK6.
90% of the population is right-handed, a really high percentage, and the reason why remains unknown. We are getting closer to the answers but our brains continue to be a great mistery.
The Evolution of Right- and Left-handedness
Source: University of Chicago Press Journals
A study from the April issue of Current Anthropology explored the evolution of handedness, one of few firm behavioral boundaries separating humans from other animals. As researchers find new cultural behaviors among chimpanzees and other primates, language is the only other characteristic accepted to be unique to humans, and both language and handedness appear to relate to the separation of functions between the two halves of the human brain, also known as lateralization.
"Modern research has shown that hand preference occurs across human cultures and, through observations of ancient art, in ancient peoples."
"We studied two groups, one a modern group of Canadians, for whom we could document hand preference and physical activity histories, as well as the breadth of the part of the humerus that makes up the elbow joint," explain the authors. "We then applied the same measurement to a group of medieval English villagers known to us only through their skeletons. This allowed us to demonstrate the usefulness of this trait to determine changes in hand preference in populations separated in time by over a thousand years. We found that the majority of active individuals display a high degree of asymmetry."
Neanderthals vs modern humans. What has the mitochondrial DNA to say?
Preliminary sequences show that the 99,7% of the base pairs of modern human and Neanderthal genomes are identical, while comparing humans with chimpanzee the percentage is 98,8%. Neanderthal DNA was extracted from the femur bones of three 38,000-year-old female Neanderthal specimens from Vindija Cave, Croatia, and other bones found in Spain, Russia, and Germany. But the greatest announcement was the discovery and analysis of Mitochondrial DNA in 2010 from the Denisova hominid in Siberia. The mitochondrial genome differed from humans by 385 nucleotides out of approximately 16,500,whereas the difference between modern humans and Neanderthals is 202 bases.
We know that the mitochondrial genome comes always from the mother, and the information found tin mitochondrial genomes gave us the chance to suggest that Neanderthals weren´t the ancestors of modern humans, but that they did share an ancestor, not that long ago
