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Genetic Drift

6/19/2016

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       Genetic drift is an evolutionary change in which it “occurs because the population is small.” How small is “small?” Did this happen and can it happen again? Is genetic drift good? But really, was IS genetic drift? In the following blog I will address these questions, and hopefully answer all questions you have about this topic.
       So, what is genetic drift. I know I gave a definition in the first paragraph, but it was a very vague definition that would only make sense to those who already know what genetic drift is. It is a random factor in evolution which means it has ties in mutation. When an allele, which I mentioned in an earlier blog (http://anthropologicalconcepts.weebly.com/blog/you-have-your-mothers-eyes) is rare in a population, a small population (a few hundred), it may not be able to pass on to the off spring because if the allele is rare, that means it is recessive. This may seem like a small thing, but this means the “genetic variability in this population has been reduced.” And in the unlikeliness of that allele being passed on, that trait dies in that population.
       That said, it answers the “is genetic drift good” question; no it is not. There is a particular type of genetic drift that can lead to another more drastic type. The particular type is called “founder effect,” in which “allele frequencies are altered in small populations that re taken from, or are remnants of, larger populations.” This type did occur, and still does occur in modern human (and nonhuman) populations. Founder effect can happen when a small party breaks off a bigger one and establishes themselves elsewhere. When they choose to procreate they will most likely choose one of their party. So over time the genes of the original founders will be the only one's in their expanded group. “In such a case, an allele that was rare in the founders' parent population but, just by chance, was carried by even one of the founders can eventually become common that group's descendants.”
​       Now, as I mentioned in the previous paragraph, there is a more drastic type of founder effect; this type is known by the term “genetic bottleneck.” The reason I call this type “drastic,” is because the effects can be extremely damaging to a species. While a small population (“with considerable genetic variability”) has a chance to get some of the same variability, an original population with the same considerable genetic variability, when a small group leave to colonize another area is where the bottleneck occurs (image below). When the population size is restored, there will be less of the genetic variability as the original population. Cheetahs for example, genetically they are an “extremely uniform species.” Biologists believe in the past there was a huge decline in numbers, and for reasons that are left up to skepticism, the male cheetah produces a “high percentage of defective sperm as compared to other cat species.” So this decreased reproductive potential, and other factors (hunting by humans for example), but the cheetah in very dangerous waters. On the subject of species, we humans are also very uniform genetically as well. Reason being a good amount of our evolution (the last 4 – 5 million years), we most likely lived in small groups, and in doing so the “drift would have had a significant impact.”
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       As I said before, genetic drift is not a good thing, mostly because the retention of a disease or condition in a population. There are some that can happen to anyone (cystic fibrosis, a variety of Tay-Sachs, sickle – cell anemia, but the last one is actually an advantage, I will explain why later), but most common within small populations. For example there is a recessive but fatal condition called Amish microcephaly, in which a mutation causes abnormally small brains and heads of fetuses. Unlike my previous statement some can happen to “anyone,” this specific condition is only found within the Old Order Amish community of Lancaster County, Pennsylvania, United States. Even though this is recessive it occur in approximately 1 in 500 births. Now I mentioned that sickle – cell anemia is an advantage, reason being those with this benign condition are more likely to be a survivor of malaria (“an intermittent and remittent fever caused by a protozoan parasite that invades the red blood cells.”) And the reason why those with sickle – cell, which provides 60% protection against overall mortality, is because, it is suggested, the hemoglobin (the protein responsible for transporting oxygen in the blood) gets in the way of the parasite and in doing so the infected results with a low percentage of infected red blood cells.
​       After this blog, I hope I have opened your minds to go beyond your neighbourhood or ethnic group to put a stop to the damage genetic drift can cause (and has caused thanks to our evolutionary ancestors). Please feel free to comment on what you thought of the blog, or other physical anthropological subjects you would like me to cover.
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The Evolution of Mammals

6/12/2016

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       I have discussed and addressed the evolution of Homo sapiens sprinkled in several previous blogs, but have not how the entire mammalian population came to be. How did a planet that was ruled by an enormous beings who were a cross between reptiles and mammals become a planet where mammals are the most common? In the following blog I will discuss how and when the mammal evolved. 
       First thing is first, who, or what was the first mammal? It may seem unbelievable but the common ancestor of all living mammals today looked like a rodent (image below). “The scientists then worked with an artist to illustrate this ancestor. In addition to a furry tail, the researchers suggest the four-legged creature likely ate insects, weighed from 6 grams (about the weight of some shrews) up to 245 grams — less than half a pound — and was more adapted for general scampering than built for more specialized forms of movement, such as swinging from trees.” This small mammalian ancestor appeared about 200,000 to 400,000 years after the extinction of the dinosaurs, which when compared to how long it took humans to evolve (5 to 8 million years), it was as if they were just waiting for the extreme threat to go away. But how did what makes a mammal a mammal come along?
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       If you were to ask a child who was just learning about mammals they would tell you that mammals have hair. We do not have a grasp why all mammals have hair, but there is a theory which, after what is theorized what happened to the dinosaurs makes sense. The reason mammals have hair was to regulate temperature, or in the case of the mammalian ancestor, to keep warm. Another big sign an animal is a mammal is if they give live birth. Again, the drop in temperature after the incident that caused the extinction of the dinosaurs played a big part in this one as well. Mammals evolved from a reptile named synapsids. Let us say the mammalian ancestor laid eggs, she would risk dying from staying still whilst sitting on her eggs. With the live birth, the female mammal is free to move gather food, protect herself, along with a myriad of other tasks. Live birth is also a huge advantage to the take over of mammals because of the fragility of eggs as opposed to incubating the offspring in the womb.
       The type of mammal that gives live birth (placental), is the type of mammal that is populating the Earth. We are currently in the “Age of Mammals,” which, as I stated earlier, started 200,000 to 400,000 (roughly 65 million years ago) after the “Age of Dinosaurs” came to an end. The synapsids were around millions of years before they evolved into mammals. “These reptiles arose during the Pennsylvanian Period (310 to 275 million years ago). A branch of the synapsids called the therapsids appeared by the middle of the Permian Period (275 to 225 million years ago).” In hindsight, evolving over a span of 100+ million years into a mammal, the evolution of humans is not so bad. That said, throughout these millions of years, the therapsids had to lose their scales thus growing hair (or fur), produce milk producing glands, and above all adapt to the changing times by having a uterus.
       All that said, it really is not that hard to believe the mammalian ancestor was so small. If you were a new species, a completely new branch of animal, being small was the best to ensure your survival. Primates for example, our, chimpanzee's, gorilla's, lemur's, every primates out there, we are all closely related to tupaiids (tree shrews...image below). Even though our mammalian ancestor evolved from a reptile, modern mammals cannot in anyway be linked to reptiles, or to any other group. “Since it can be shown that each of the 32 orders of mammals are separate and distinct groups set apart from one another and from all other creatures by unbridged gaps, it seems evident that collectively as mammals they are set apart as well.” 
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       Earlier I did state that to be a mammal live birth is a factor, but in the case of monotremes this does not apply. What I mean by this is that monotremes are mammals who lay eggs. The species that fall into monotremes are not many, in fact, there are only two; the platypus and the echidna. I mentioned placental earlier, aside from it meaning to give live birth, it also means “presence of a placenta, which facilitates exchange of nutrients and wastes between the blood of the mother and that of the fetus.” This, of course, does not apply to monotrems, but it also does not apply to marsupials, even though they, in a way, to give live birth. But no matter our differences, we are all mammals, and this is our age.
​       Please feel free to comment on what you thought of the blog, or other physical anthropological subjects you would like me to cover.
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Deviant Burials

5/22/2016

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       Death is still something frightening to some. What does happen after we die? Do we go to heaven? Are we reincarnated? Or is there a chance for us to become the walking dead? The fear of the dead is more prevalent than the fear of death itself. This fear goes back ages, before modern zombie television shows and movies. In the following blog I will discuss ways cultures made sure their dead would not rise, the first recorded culture to take this fear seriously, and a culture in which had the mind set that the dead should not be feared.
       Necrophobia is the fear of dead bodies (necro: relating to death, phobia: extreme fear of). Like most phobias, whether it be the phobia of clowns or of heights, is an irrational fear. Once the body is dead, and I am meaning the second the blood stops pumping, unless certain measures are taken (a defibrillator for example), there is no chance of it coming back to life. But necrophobia is not just the fear of the dead, this fear can be of funerals, coffins, cemeteries; anything relating to death. It may sound silly when explained, but silliness could not have been further in the minds of those with this fear when dealing with the dead. Some would place huge boulders on the body to pin it down, some would spear the body to keep it in place, some would disembowel and dismember their dead, and in the case of Albert I, in 1225 his body was boiled and defleshed.
       As for the earliest known method to keep the dead in their graves comes to us from the ancient Greeks; who feared zombies. What the ancient Greeks would use were large amphora (“two handled ceramic vessel that was generally used for storing wine and olive oil”) which were “presumably intended to pin the individual to the grave and prevent it from seeing or rising.” They were also the first to use huge stones to weigh a body down as was seen when a burial of a child was found. That said there is evidence in the form of tablets inscribed with magical spells that some wished to resurrect the dead and have them do their bidding.
       Long before the ancient Greeks existed a culture and way of life that did not fear the dead. This culture belonged to the ancient Egyptians. In one of my earliest blogs (http://anthropologicalconcepts.weebly.com/blog/-are-you-my-mummy) I described how the process of mummification took place. You can argue that the ancient Egyptians feared their dead because of the way they prepared their dead; from disemboweling them to wrapping them in tight linen. But we have to remember in the time before being wrapped there were priests who had to come daily to “feed the soul” of the dead pharaoh. Not only that, but when they were entombed in their grave, it was not seen as a sign of “beware,” but it was a sign for celebration. Celebration because their pharaoh was going into the afterlife and because to the ancient Egyptians their pharaoh was the embodiment of a god.
       Now, why after give or take 2100 years after the ancient Greek's necrophobia ways are we still afraid of the dead? I mean, in early Anglo-saxson history, they would behead their dead before burying them, and this was a time between 410 – 660 C.E. So why do we, some 1356 years later still fear our dead. Our fear may not be as extensive as to behead our dead or weigh them down with large stones, but we still fear our dead. The reason being, and which I think it always has been, the dead remind us of our mortality. They remind us that we will eventually expire...we will eventually die.
       Please feel free to comment on what you thought of the blog, or other physical anthropological subjects you would like me to cover.
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Alopecia

5/8/2016

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       You may know a number of people who suffer from alopecia; it may be your dentist, a co-worker, maybe even one of your parents. I spoke of this briefly in a previous blog (http://anthropologicalconcepts.weebly.com/blog/-getting-older), and what alopecia means, in layman terms, is hair loss. In the following blog I will discuss why it is more prone in specific ethnicities, why it is seen more in men and balding in women, why the body hair continues to grow while the head hair stops, and all in all why it happens.
       It may seem that those we see with alopecia are mostly of European descent, but why? It is strange that those of European descent have the fastest growing hair, but the men of this descent “have more hair loss above the forehead than other races. Asians, Native Americans, and men of African descent usually have less hair loss than Caucasians.” It has been theorized that European men make more dihydrotestosterone (DHT, which is a part of the hormone testosterone), which plays a big part of those of European descent having more body hair, but more prone to alopecia. This does make sense when comparing the hairy European to the less so, Asians for example, of which we do not see many balding Asian males. Although, that said, ethnicity is only part, a small part, of why someone would have alopecia; we have to take genetics, lifestyle, and how one takes care of their hair. An example is the alopecia with Afro-Caribbean hair. With those of this culture the hair requires constant pulling of the hair to achieve certain styles.
       Now as I stated in the opening I spoke of this condition in a previous blog, and in that blog I explained how the loss of hair in males is mostly a cause of the hormone testosterone, but there are cases of alopecia in females as well, which have a very small dose of this hormone (which is why females tend to have less body hair). When a man is going bald it is usually called “male pattern baldness,” but when a woman is going bald it is referred to “thinning” because they do no experience a complete loss of hair. The reasons for this “thinning” varies from stress to a hormonal fluctuation “such as post-partum or menopause.” But it can also be genetic. Women with the thinning of the hair will sometimes find that their mother and grandmother also has this “thinning.”
       In the case of genetics, this is the most common cause for male pattern baldness. It is believed that the mother is one that passes on this androgenetic alopecia because it is on the X chromosome (which is passed on from the mother), but in many cases of alopecia, the father is also suffering from male pattern baldness. Even though alopecia is found on the X chromosome, it is actually the fault of a male sex hormone named androgens. When a male becomes increasingly sensitive to androgens, they will experience hair loss. With all that said, even if the mother, the father, or even the grandparents do not have a case of alopecia, as long as there was any case in a family line it will come up again sooner or later.
       For this entire blog I have been explaining several causes and reasons for alopecia, but it all adds up to the question...why? There have been studies to answer this question, but at the end of it we know “how,” but that still leaves the “why?” An extended reasoning in how alopecia happens is that when, in male pattern baldness, the hair follicles become smaller and the growth phase of the hairs is reduced. This reduction the maximum length is shortened, and the same time the resting phase is lengthened. It becomes a cycle and the rest phase becomes the most prevalent. “Over time, the anagen (the growth) phase becomes so short that the new hairs do not even peek through the surface of the skin.”
       We may never know when or just why alopecia began. And unlike the things people experience when getting in old age that I discussed in the blog I linked above, alopecia can happen at any time. The most common is when you do get older, but it really can happen any time after puberty. I suppose you can group hair loss in the category of getting older, but...not that much older.
       Please feel free to comment on what you thought of the blog, or other physical anthropological subjects you would like me to cover.
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Albinism

4/24/2016

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       Melanin is something most everyone has, which is “a dark brown to black pigment occurring in the hair, skin, and iris of the eye in people and animals. It is responsible for tanning of skin exposed to sunlight.” Whether the person is dark skinned or light skinned, most of us have a good percentage of it in us. Now, I did say “most of us,” meaning there is a small percentage of the human race which is either lacking it in their eyes, or entirely devoid of it. That small number (1 in 20.000 people worldwide) of people have a rare condition called “albinism,” which is what this blog will be addressing. I will speak of types of albinism, the origins of it, and of other species that also express albinism.
​       Unlike other birth based disease (HIV, autism, etc.) which are evident from the time of birth give or take a few months and have one type, albinism has 2 types, but one of the types has 4. The one that contains 4 different types is called oculocutaneous albinism. The type 1 for this is what you would think of when you hear “albino.” Those with type 1 have milky white skin, white hair, and unlike the myth that they have red eyes, most with type 1 have blue eyes. With type 2 (most common in sub-Saharan Africans, African-Americans, and Native Americans), they still have milky white skin, but the hair “may be yellow, auburn, ginger or red, the eyes can be blue-gray or tan.” And unlike type 1 in which too much sun exposure will lead to skin cancer, type 2, when exposed to the sun, overtime may develop freckles, moles, or lentigines (sun spots). Type 3 (most common in black South Africans), do not have milky white skin. In fact, unless you knew they had albinism, you would not know. Their skin is usually reddish-brown, with ginger or reddish hair, and hazel or brown eyes. The 4th type is similar to that of type 2, but it mostly found in those of East Asian descent. The second type of albinism is known as ocular albinism, which affects the eyes, and is mostly found in males. This is caused by a mutation of a gene on the X-chromosome. Those with this type have problems with their vision, but aside from that, their skin, hair, and eye colour are generally in the colour range of those in their family. Even though albinism is very rare, there are rare disorders in it; an example is that of Hermansky-Pudlak syndrome. This rare albinism disorder is caused by a mutation in one of at least eight different genes. People with this disorder are more common in Puerto Rico. Those with this disorder have similar symptoms with those with oculocutaneous albinism, “but they may also develop lung and bowel diseases, or a bleeding disorder.” But how is one born with albinism? The answer to this question can be summarized in one word, “mutation.” All it takes is a different gene, like in autism for example, to change everything. The image below illustrates how improbable it is to be born with this disease; and unlike HIV, albinism is in no way contagious (you can refer to a previous blog in which I speak of punnett squares like the one below here: http://anthropologicalconcepts.weebly.com/blog/you-have-your-mothers-eyes)

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       For this disease there is no “patient zero.” But, that said “Albinism is said to be the oldest anomaly ever recorded.” Records for people with albinism can be traced to 1660 in which the term “albino” was first coined to the historian and missionary Balthazar Tellez. In his travels he first saw evidence of albinism on the West African Coast. Although that is a specific year, many years before that the Greeks had encounters with and words for those with albinism, one was leukoethrope (white), and leukoethiopians (white Ethiopians). More “recently” in United States history when slavery was still instilled, in 1869 Joseph Hones MD. published “Observations and Researches on Albinism in the Negro Race.” In this publication he claimed that those with albinism showed superiour intelligence because of their “superior” colour. He lumped those with vitiligo (image below) and albinism together, saying they “turned white in the womb.”  
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      This disease is not limited to humans. In our subfamily Homininae, there is another ape that has showed humans are no the only ape known to get albinism. On October 1, 1966, a lowland gorilla was captured in a region of Equatorial Guinea; a gorilla the world came to know as Snowflake (image below). He was originally named “white gorilla,” because his hair was white. Since his time of capture to the time of his death he was a celebrity at the Barcelona Zoo in Spain. Now, unlike humans, the reason for his albinism was because of inbreeding. After his death, his blood was tested and “they were able to determine that his mother and father shared 12 per cent of their DNA and concluded that this likely made them uncle and niece.” He passed away on November 24th, 2003 because of skin cancer. All that said, albinism is not limited to hominids. We all know of the white mice/rats and polar bears, but they are not albino, in the case of the polar bear it helps them blend in with the snow (this is an evolutionary advantage). But for other animals, much like with humans, their colour makes them stand out. There is a moose (image below) in Ontario, Canada who seems to blend in with the snow of their environment like the polar bear, but, as the opposite of their brethren who have very dark coats to help them camouflage with the woodlands, this moose is much more visible to wolves...and humans. 
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       This disease seems to have plagued all manner of species; mammal, invertebrates, reptiles, birds all seem to be susceptible to albinism (images below). Let us hope that in those animals we find to have albinism are aware enough to keep out of sunlight, but, that said, I am sure they do because “The lack of pigment in the eye alters the amount of light entering the iris, leading to excessive exposure to brightness. As a result, albinos of any species, including humans, may experience great sensitivity to light.”
​       Please feel free to comment on what you thought of the blog, or other physical anthropological subjects you would like me to cover.
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Looting (Reader Requested Topic)

4/10/2016

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       In a previous blog (http://anthropologicalconcepts.weebly.com/blog/nagpra), I gave a list of an ethical outline that archaeologists and, really, all anthropologists must follow, but there are those who seem not to have ethics when ancient artifacts come into question. Some who are just looking for more information (Thomas Jefferson for example), but some are looking for a way to make a monetary profit. In the following blog I will address how the idea of looting has changed and how it is not only stealing physical objects, but robbing us of so much more.
       During the early 1800's the world went mad for Egyptian artifacts; whether to see them, own them, or find them. In this time many people were hired by museums to get the the most rare artifacts they could. One man, Giovanni Belzoni, was the most prolific when finding Egyptian antiquities. Then he was seen as a great explorer, a treasure hunter, and the finder of the treasure which he was hunting for. Many are thankful for his findings (bust of Ramesses II, Abu Simbel which is still known as “Belzoni's Tomb”), but by today's standing, he is seen by some as a looter. In a sense he, all who were digging and finding artifacts in this time, were similar to those who looted the tombs of the pharaohs. When those in the 1800's would open a tomb, expecting to find riches beyond their wildest dreams, but ended up seeing it had been pillaged; those who looted irreplaceable artifacts robbed something more than riches.
​       The culture, the valuable information that can only be taken away from items left in tombs, is the true harm looters bring to us. For example, the chair in King Tuts tomb that depicts his wife touching him (image below) shows us that he indeed loved her, that he was a caring person, much like his father, who is shown playing with his children (image below). If that tomb had been looted, everything we know about King Tut, like his age (because there were artifacts that seemed they were a child's) would have been lost to the ages. In other instances where there is no structure like a pyramid or the like, the artifact is underground.  
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       These looting instances are amoung the most horrendous. If you remember in an earlier blog about dating (http://anthropologicalconcepts.weebly.com/blog/dating-methods-have-you-found-the-right-one) I spoke of stratigraphy and when someone comes along digs and takes what they find without keeping a log of it, they compromise the archaeological record (this means they compromise the surrounding environment and the stratigraphy, which in turn compromises the dating). Not all looting is taking items from tombs. Looting can be finding an artifact and taking it. For example, the possession and transporting to a foreign land of infamous Rosetta Stone, if it had been found nowadays, it would still be in Egypt, and not at the British Museum. But, like thoughts on Belzoni, many are thankful that Napoleons soldiers discovered this stone (without it, we would not know much about how to read hieroglyphs, as discovered by Jean-Francois Champollion, and in loss of that knowledge, not knowing much about ancient Egyptians, period).
       Although it really is amazing how much we have evolved to treasure these artifacts. It is a great contrast between the finding of Egyptian artifacts in the early 1800's and in the early 1900's; King Tut's tomb to be more specific. This famous tomb has to be one of Egypt's national treasures, because unlike the Rosetta Stone, or all the other Egyptian artifacts in museums around the world, he is still in the desert, he is still in Egypt. Shortly after the opening of the tomb, it seemed as though things were missing and the prime suspect was Carter (he claimed the tomb was opened before, but this was highly doubtable, he even illegally entered without waiting for Egyptian officials). “"All objects from the tomb should be in Egypt, and if they're not in Egypt, they didn't get out legally,” said Dr. Loeben, a German Egyptologist.
       Most recently, there has been a massive loss of culture; Syrian culture to be more specific. In recent news reports, it has been the terror group who call themselves ISIS that have not only been looting but destroying. It began as the bombing of archaeological sites in Syria which held ancient architecture, but then “what isn't destroyed is being quietly sold on a black market that reaches Europe and even the U.S.” Not only are they destroying a vibrant ancient culture (most likely their own), but they always have been giving licenses to looters so they are able to dig in their territory, and "If you find an artifact, you take 80 percent and ISIS takes 20 percent," said an informant for CBS news. This level of cultural destruction has rivaled what happened during WWII, when the Nazi's took artifacts for their own. What really makes this heartbreaking is that unlike the artifacts the Nazi's looted that were eventually recovered, what ISIS has done, has taken it to a level at which we can never hope to get back those artifacts, those environments, what made that culture that culture.
       With all the information we have learned by past and/or dead cultures, the artifacts play an essential part. From arrow heads, to the most brilliant stone, it all holds answers to who these people were in life. But looters are not only in days of old, people who steal or rob other are looters because everything we have are artifacts; your shoes, your spoons, even the device on which you are reading this on is an artifact. An artifact is anything man made, and those man has made in the past are just as precious as those we have now.
       Please feel free to comment (or email me at: anthro302@gmail.com) on what you thought of the blog, or other physical anthropological subjects you would like me to cover. 
(video below is a CBS report about the looting of ISIS)
View More: The fight against ISIS News|World News|Live News|More News Videos
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Mating

4/3/2016

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       We are all acquainted with what mating involves in humans. Whether it be a physical, emotional, sexual, or all of them, we have a good idea of what it consists of. But what of non-human primates? In the following blog I will address the selection of a mate, the subject of infants, and of “families” in non-human primates.
      As humans, we are not attracted to other species, such as chimpanzee's or the like; sure, we think they are cute, but not “mate” material. But for the females of the different species of ape, some have a choice with whom to mate with. For most of them there is a polygynous system, in which there is one male mating with several females. In a previous blog (http://anthropologicalconcepts.weebly.com/blog/sexual-dimorphism), I discussed sexual
dimorphism; in those in which there was a great deal of sexual dimorphism, there is a competition. It is usually the one with the most evident sexual dimorphism that is able to mate. Although, in those who do not have great sexual dimorphism, they usually live in pairs while the child is being weened. Some of those are monogamous, some also mate with other females, but for those they will stay with the female they impregnated. “Primates are amoung the most K-selected of mammal species.” K-selected means that they produce a low number of offspring so as to invest more time with the one child (the opposite is r-selected in which a large number of offspring are produced). With female primates, they spend most of their adult life “being pregnant, lactating, and/or caring for offspring.” For Old World apes their genitals swell and change colour, so in some they do no have a choice.
       In some males, since they do not have invest in rearing the offspring, the want to produce as many offspring as they can; which is sometimes dangerous...to the offspring. What I mean by this is if another male becomes the leader of the pack, they will commit infanticide with the offspring that is not theirs. Even though this is highly counter-productive for the species, the males “need” to do this. Reason being is while the mother is lactating and caring for her offspring, she does not come into estrus (heat), and therefore is not sexually available. So the new male in charge kills the offspring, so that he only has to wait two to three months, and not two to three years to mate with the females. In chacma baboons, for example, they “deliberately single out females with young infants and hunt them down (image below).” All that said, it does not prove the male's reproductive fitness. What primatologists look for are two crucial facts:
  1. Infanticidal males don't kill their own offspring,
  2. Once a male has killed an infant, he subsequently father another infant with the victim's mother.
But chacma baboons are not the only species in which the males practice infanticide; others include Hanuman langurs, redtail monkeys, red colobus, blue monkeys, howlers, orangutans, gorillas, chimpanzees, and, sadly, humans. 
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       But it is not all bad news for the infants for one reason, their mothers. Not counting those communities with polyandry (female with many males mates where the males is in charge of rearing the offspring), the bond between primate mothers and their infants begins at birth. We are not sure what the bonding process is, but if the mother had a normal experience with hers, it is evident early. In other cases were the female was raised in captivity without knowing their mother, she will most likely be afraid of her offspring, or kill it. Although, when the female has had a normal relationship with her mother, she knows what to do. As for the infant, it is as if it is automatic, as they grasp onto their mothers fur, and are in this constant contact for several months (which gives you an idea why some males would commit infanticide). While in this contact, they are exposed to social behaviour. In many primate communities they allow alloparenting, which is when those who are not the parents of said infant carry, hold, and just interact with them. But the mother has to be careful because there have been instances of the death or injury of the infant due to the inexperience or aggressiveness. This alloparenting is very useful just in case the mother dies or is unable to take care of her infant. Amoung the siamangs, marmosets, and tamarins, the males are actively involved. And in the case of marmosets and tamarins, the infants are frequently twins, so the father carries them on his back and are only away from him when nursing with their mother.. Even in those species where they do not actively involved, the exhibit paternal care. For example, “they showed that during disputes, the fathers intervened on behalf of their offspring significantly more often that for unrelated juveniles.”
       This interaction with not only their mothers, but with their “aunts” is very important for not only the infant but those females who have yet to give birth. Being with those infants is a way for them to learn what to do. But, in the case of infants who have undergone social isolation, it is obvious they need it. They have been recorded displaying self-direct behaviour, such as hugging themselves or rocking back and forth. For the social group in these primates it is suggested that the mother-offspring core gives it stability.
​       Please feel free to comment on what you thought of the blog, or other physical anthropological subjects you would like me to cover.
Images above from left to right: Patas monkey, Mongoose Lemur, Orangutan, Chimpanzee, Sykes monkey
Click to image to make bigger.
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Evolution of Language

3/27/2016

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       Day to day we do not take into account the words we use, words we read, or words we hear. All this makes up language. There are roughly 6,500 languages in the world. Humans are the only species with a spoken language. But what of our cousins? In the following blog I will discuss the way non-human primates communicate, how we are able to communicate with them, and what makes the Homo sapiens so special as to have a spoken and written language.
       Most non-human primates have a system of communication. To us it only sounds like, well, sounds, but to others in their species, they know exactly what they are saying; or feeling. The sounds chimpanzees make or when a baboon barks are being made to tell others in the group what they are feeling. They have sounds for happy, sad, angry, excited, but that is the extent to their “language,” to help others understand what they are feeling. I would say that was the only thing they can communicate, but we have to remember that most small non-human primates have predators, and as such, need to communicate extensively to keep safe. For example vervent monkeys (image below), they use different vocalizations to warn of different predators. The vocalizations for birds or pray, snakes, or leopards are different. With the snake-warning call they look at the nearby ground, with the birds of pray-warning call they look towards the sky, and with the leopard-warning call they quickly climb the trees. To those who hear them once, they all seem the same, but with attentive ears and hearing them call over and over again, it becomes clear which ones mean which predator. Other non-human primates that have this system include (images below) cottontop tamarins, Goeldi's monkeys, red colobus, and gibbons (there are also birds and non-primate mammals who use specific predator calls).  
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       So if we know how they communicate we should be able to communicate with them, correct? But what if they want to communicate with us? Before I go on any further I wanted to make something clear, the major reason for non-human primates is not because of the lack of intelligence (they are very intelligent), but because of something they lack. “The fact the apes can't speak...with the differences in anatomy of the vocal tract and language-related structures of the brain.” If they could speak, I am sure they would be seen as human as...humans. That said, there is a movement to get chimpanzee's to been seen as human, but I am getting off topic. Many apes throughout the years have found a way to communicate with us humans in ways we can clearly know what they mean. Before it was thought they could not speak of the future or past, only in terms of present events and present peoples. But that all changed with an infant chimpanzee named Washoe. In 1966 the project of teaching her sign language began, and within 3 years her “vocabulary” consisted of 132 signs. “She asked for goods and services, and she also asked questions about the world of objects and events around her.” And years later when they brought a young male chimpanzee named Louis, she deliberately began to teach him when the researchers were not.
​       In 1967 another chimpanzee, named Sara was “taught to recognize plastic chips as symbols for various objects.” What made this interesting is the chips did not look like the object she would ask for. For example, the chip for apple was not round or red. This was exciting because it showed that she could understand symbols for different objects. Something else happened in the late 1970's that was just as exciting. If you remember in my previous paragraph that non-human apes did not speak of past or future events or refer to those who were not present; but that all changed with a 2yo male orangutan named Chantek. He built up his sign language vocabulary to 140 signs, “which he sometimes used to refer to objects and people not present.” He would also combine signs to make more clear what he was speaking of, he was the first to do this, but not the last. In the early 1970's a gorilla was born, a gorilla the world now knows as Koko. This magnificent gorilla does not have a vocabulary of 140, or 500, not even 1000; her vocabulary is more than 1000, and to add to that, she can also understand more than 2000 words spoken in English. As I said, just like Chantek, she has made very clever signs for things she wants. For example the sign for “scratch” and “comb,” she was asking for a brush (video below), or with the sign for “eye” and “hat” she means “mask.”  
       With all we have had to do to communicate with non-human primates, why is that we are able to communicate with other humans? Why do we have something called “language?” For the answer to that we have to look at the brain. Some argue that our language capabilities began 10,000 – 30, 000ya, others think it was earlier with the appearance of Homo (2mya). “In most people, language function is located in the left hemisphere...In particular two regions, Broca's area in the left frontal lobe and Wernicke's area in the left temporal lobe are directly involved in the production and perception, respectively, of spoken language (image below).” Broca's area is located near the motor cortex, right next to the area that controls the face, lips, larynx, and tongue. The Wernicke's area involved in the perception of sound. If a lesion in Wernicke's area is damaged, it does not impair hearing, but rather the comprehension of language. I have gone one about these two areas of the brain as if only humans have it, but that is not true. In examined chimpanzee, gorilla, and bonobo brains they have a larger Broca's area on their left side. But, that said, it is the same area that harbours the motor aspects of gestural language in humans; “speech production in humans was present, at least in a incipient degree, in the last common ancestor of humans and the African great apes.” In short, the shared cognition abilities of primates (especially apes), lead to some symbolic capabilities, which lead to the increased communication abilities and development of symbolic thinking (which was a huge and important step for both neurological reorganization and anatomical modifications of vocal tract), and all this lead to where we are now, a world full of languages; human languages.
​       Please feel free to comment on what you thought of the blog, or other physical anthropological subjects you would like me to cover.
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NAGPRA

3/20/2016

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       In a previous blog (http://anthropologicalconcepts.weebly.com/blog/evolution-of-anthropologists) I spoke of how Thomas Jefferson conducted his own excavation of one of the Native American burial mounds in Virginia. Even though he went through it carefully and systematically, if a president tried doing what he did after the 16th of November in 1990, NAGPRA would be all over them. In the following blog I will discuss what NAGPRA is, why it is important, and how this affects both archaeologists and anthropologists alike.
       So what exactly is NAGPRA? It stands for Native American Graves Protection and Repatriation Act. This is a Federal law that was passed in 1990 that provides systems for museums and Federal agencies to return a number of Native American cultural items. These items are human remains, funerary objects, or objects of cultural patrimony. When obtained, they are then returned to the “lineal descendants, and culturally affiliated Indian tribes and Native Hawaiian organizations.” Even though a few of the burial mounds were excavated, there are parts of the Native American heritage everywhere. We have to remember how long they were living in the Americas before Europeans came to their shores. Since they were forced out of their home lands, they left a lot behind. So when someone finds a bone the excavating begins. If a funerary object is found or anything that has to do with Native Americans, they will call NAGPRA. That said, even though they are called, then begins the detective work to whose tribe it belongs to.
       Now even though the law was passed in late 1990, during the 1970's and 1980's some Native Americans argued that they were relations to some of the skeletal remains in museum collections. The problem with this is when one tribe claims to be a relation, others chime in in case they are wrong and they are one of theirs. The best example for this is “Kennewick Man (or “Ancient One).” These skeletal remains were found in July of 1996 “below the surface of Lake Wallula, a section of the Columbia River pooled behind McNary Dam in Kennewick, Washington.” When they were found the tribes of Umatilla, Colville, Yakima, and Nez Perce each claimed Kennewick Man was their ancestor. These remains were examined, measured, carbon dated (dated to over 9,000ya), and went through a myriad of tests (from CAT scans to X-rays). At first it was believed Kennewick Man was Caucasian, but when they where given to Native Americans to examine, it turned out he was not European, or Native American, or modern at all. To this day, the matter of who Kennewick Man was is still unresolved.
       As you can imagine the newly formed NAGPRA has affected how archaeologists and anthropologist practice their studies. Native Americans were amoung the first “other worldly” cultures Franz Boas (father of American anthropology) studied. In an instance in 1897 he requested to be brought six Inuit people from Greenland to the Museum of Natural History to  "obtain leisurely certain information which will be of the greatest scientific importance" regarding their culture. But in six weeks all six became sick, and as they had been shown in their tribe, they began to perform tribal healing process, and in doing so were mocked by it. In the early stages of anthropology the Native Americans, were seen as a form of “entertainment.” Before the coming of the NAGPRA law, anthropology had grown to respect and see these cultures as people and not as they were seen in the early years. “The promotion of ethical behavior is an important aspect of the society's (Society for American Archaeology) activities.” The following are eight ethical principles of the Society for American Anthropology:

  1. Stewardship. The archaeological record is irreplaceable and it is the responsibility of all archaeologists to practice and promote stewardship of the archaeological record.
  2. Accountability. Responsible archaeological research requires a commitment to consult with affected group(s) to establish a working relationship that can be beneficial to all parties involved.
  3. Commercialization. The buying and selling of objects contributes to the destruction of the archaeological record on the American continents and around the world. Archaeologists should discourage and avoid activities that enhance the commercial value of archaeological objects.
  4. Public Education and Outreach. Archaeologists should work with the public to improve the preservation, protection, and interpretation of the record.
  5. Intellectual Property. A researcher may have primary access to original materials and documents for a limited and reasonable time, after which these materials and documents must be available to others.
  6. Public Reporting and Publication. The knowledge that archaeologists obtain in their investigations must be presented to the public.
  7. Records and Preservation. Archaeologists should work actively for the preservation of archaeological collections, records, and reports.
  8. Training and Resources. Archaeologists must ensure that they have adequate training, experience, facilities, and other support necessary to conduct a program of research.

       Out of these eight principles the one that is the most prevalent when excavating in foreign counties is the third one. It is not because of the fault of the archaeologists, but that of looters. Even if it is their past, some could not care less and just want to make quick money. But if they are found to be selling something with a Native American origin they are arrested and questioned. When there is are skeletal remains in the picture, a physical anthropologist is called, and the ethical rules are just as followed by them.
       The Native American peoples are not dead, and neither is their culture. Many go about with “Indian” Halloween costumes without really understanding who they are dressing as, the symbolism the headdress, the beads, even the colours signify. Those who live in the United States do not think twice about the rich culture who this soil was robbed from. The least we could do is give the pieces they left behind back to them, not rob it like we did their land. Here is a link to the official NAGPRA website it you are interested in reading more into it: http://www.nps.gov/nagpra/.
       Please feel free to comment on what you thought of the blog, or other physical anthropological subjects you would like me to cover.

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Osteoblasts and Osteoclasts

3/13/2016

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       When we hear the word “bone” we either think of a dead material or what we have inside that just serves as a way to keep us from being a mound of muscle and tissue. What I am saying is we never see bone as “alive.” Sure we see our friends, family, and every human we see as alive, but we do not give much thought into the bones of those we see as alive. In the following blog I will discuss the “living” our bones have been doing since we were conceived.
       You have heard parents speaking of their children and saying how fast they are growing. This growing is all thanks to the osteoblasts and osteoclasts. Before I go any further I think it best to clear up what these blasts and clasts are all about. On the cellular level, osteoclasts remove bone tissue and osteoblasts build bone tissue. In short, these two remodel bone. In children, mostly infants, one hundred percent of their skeleton is remodeled, so it is not so far to say they grow fast. Now bone is relatively light weight. This is because of the relationship between the osteoblasts and the osteoclasts. Without the removal of the bone tissue which is the job of the osteoclasts, the osteoblasts would keep making bone tissue, and in doing so make it very thick, and thus, making the bone heavier.
       Now the work of the osteoblasts and osteoclasts do not stop during the years after maturity. As I am writing this, my osteoblasts and osteoclasts maybe hard at work. In adults they get to work every 3 months or so. Our bones are constantly changing. Maybe not the extent of younger humans, but the average adult has about ten percent of their bones remodeled every year. But even though these osteoblasts and osteoclasts seem like a well oiled machine, sometimes things go wrong (image below is what is supposed to happen).
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       The thing that goes wrong is called osteoporosis. This is “a medical condition in which the bones become brittle and fragile from loss of tissue.” The tissue they are talking about is the bone tissue, or sometimes called “bone loss.” A cause of this is an imbalance in hormones, which leads to the imbalance of what the osteoblasts and osteoclasts do. Since the bones become fragile, this means the osteoclasts are the only one doing their job. This form of hormonal imbalance osteoporosis is most common in postmenopausal women, but there is another that is age related that can happen in the 20's. “Recent studies indicate that significant trabecular bone loss begins as early as the twenties in men and women—long before any major hormonal changes. In women, however, bone loss accelerates for 5 to 10 years after menopause due to the rapid decline in estrogen levels; after this phase, bone loss continues at approximately the same rate as in elderly males. These observations indicate that there is an element of the aging process in bone, other than an age-associated failure of other organs or tissues, that is a common cause of bone loss in both aging women and men.”
       That last paragraph makes osteoblasts and osteoclasts out to be something terrifying; almost like being eaten from the inside out. But these help us in more ways that keeping our bones healthy and strong. For example, when a bone is broken. A broken bone has a few steps to heal, from quickly forming a clot to stabilize the bone, to creating fiber of collagen (“the major protein in bone and connective tissue”). After all this is done, the last step and line of defense are the osteoblasts and osteoclasts. “Osteoclasts and osteoblasts spend months remodeling bone by replacing the bone callus with harder compact bone.” These elements are crucial for our survival. They may go mad in some cases, but, that said, it is thanks to this team of destroy and create that we are able to grow and rebuild.
       Please feel free to comment on what you thought of the blog, or other physical anthropological subjects you would like me to cover. (animation below is an example of what the osteoblasts and osteoclasts do). ​
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