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The Evolution of a Penguin

           In the 21st century, many humans wonder why Penguins are so unique.  James Randerson says  " They have a dinner-suit plumage and waddling gait, penguins are among the most unusual and endearing members of the bird kingdom." Something has caused penguins to change.  The scientific community has researched the changes, finding evidence that supports the Penguins evolution. In the beginning, scientists believed that penguins evolved from a flying bird that dated back to 150-million-year-old Archaeopteryx. According to Bnet.com, Ornithologists agree that, "Their closest living relatives appear to be an albatross, the graceful, soaring birds celebrated for their ocean-spanning trips in search of food for their young, says Marcel van Tuinen." Why is it that Penguins can not fly and how have they evolved?

The reason why Penguins cannot fly in the "Air" is because of their habitat. During the time of their evolution from a flying bird, they didn't need the ability to fly. Usually flying birds have hollow bones because they decrease the weight of the bird. A decreased weight equals a smoother flight for the bird. In the case of the Penguin, its wings are heavier so they can move through the water more rapidly. Many scientists would say that they "Fly" through water. Other researchers believe that Penguins evolved because of micro-evolution. It was used regarding because penguins were forced out of their normal habitat and because of that, they had to interbreed with members of different colonies. One idea, from MSNBC, was that "the breakup of mega-icebergs was blocking the swim paths of penguins and forcing them to migrate to more accessible colonies." Today, most species of the Penguin live in the Southern Hemisphere. The Penguin life varies from species to species. 

       Penguins live abundantly on many temperate and sub-Antarctic islands. Depending on where the Penguin is located determines its body structure. Galapagos penguins, which do not have the normal thick body structure, are located on tropical islands at the equator. Compared that to the emperor penguins that have a very thick layer of body fat , which are restricted to the pack ice of Antarctica. With all of the research done by scientists, similar to humans, there is still a missing link as to how Penguins have evolved, but only time will tell.

Sources :

http://www.penguins-world.com/penguin-evolution.html

http://findarticles.com/p/articles/mi_m1200/is_22_166/ai_n8576738/

http://www.guardian.co.uk/science/2007/jun/26/fossils.uknews/print

http://www.msnbc.msn.com/id/9967766/


http://media.photobucket.com/image/penguins/kremar15/Penguins.jpg
prehistoricpenguin
Penguins
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How has the stereotypical role of a women developed an evolutionary basis?

Since the beginning of time, women and men were on two different scales. Women are usually the housekeepers and did not have much say in society. Because they are the housekeepers and produce milk for their young this is an evolutionary basis.

For some animals there are males that produce milk or lactate, just as a woman does. I would consider this an evolutionary basis as well because this is usually something that happens in women. Or what should only happen in women.

Just as human women produce, there are other animals species who are able to produce as well. Although this is true, the reproductive system is different for all. Animals can reproduce more than one child at a time. For example a fish can have multiple babies at one time, but human women can only have one baby at a time or if they or their partner carry the gene, can have twins which isn’t as common in the human population. It’s also different with breastfeeding. There are some male animals who lactate and human men are able to lactate as well.

One of those animals is The Dayak fruit bat is a bat that produces milk, but this is a normal function of the bat. Also there is a male goat that produces milk on occasion. According to an article called Male Lacation by Professor Patty Stuart Macadam. Human men are able to lacate after having a baby suck on the nipple after several weeks. This shows the evolution of the human women role to it being passed on to men.

There are also other male mammals that do not lactate but have the role of the “stay at home,” the Deer Mice is one of these. According to NOVA Online, the Deer Mice guard the young while the other goes out to eat This shows how the roles of the partners can be switched up, for different reasons.

In human society, this is not the case with men. Men cannot reproduce but they are the reasons on why reproduction is possible. It shows how closely related we are with animals but how we are also different.

 

Further questions:

Why are there mammals that take on the role of the “stay at home” but are not able to lactate?

Why can the Dayak fruit bat lactate but not breast-feed? What is the propose?


Citations:

Comparison, By. "Statistics Bureau." Web. 02 Nov. 2010. <http://www.stat.go.jp/english/data/handbook/c02cont.htm>.


Shanley, Laura. "Milkmen: Fathers Who Breastfeed." Bornfree! Laura Shanley's Unassisted Childbirth Page. 27 Sept. 2007. Web. 08 Nov. 2010. <http://www.unassistedchildbirth.com/miscarticles/milkmen.html>.

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How has the shape of the human shoulder propelled us to the top of the animal kingdom?

Throughout history, human ancestors did not always possess the ability to throw, a skill that propelled them to the top of the animal kingdom. This skill is based in the shape of the shoulder joint. In apes, this joint opens upwards, making it ideal for hanging on trees, but incapable of accurate projection. As humanoids turned to walking as their primary means of transportation, the joints and shoulder blades slowly fell. Approximately 500,000 years ago, they arrived in their present horizontal, coat-hanger-like position. 


Ape Shoulder
Human shoulder
Ape shoulder (top) and human shoulder (bottom)

With a joint that opened horizontally, instead of vertically, early humans were able to rotate their arms in an almost any direction. This semi-boundless motion allowed them to throw with an accuracy much greater than that of their ancestors.  Apes are known to throw rocks, but soon humanoids began to hunt with wooden spears, placing them at a great advantage over any other animal.


The use of projectile weapons was one major difference between Neanderthals and modern humans. In the midst of their relatively rapid evolution, it is possible that Neanderthals' bodies never evolved to allow accurate throwing. It is hypothesized that their shoulders were much more ape-like in shape and position. According to Steven Churchill, an anthropology professor at Duke University, "Perhaps their...short, squat body build with short and massive limbs was not conducive to using throwing-based hunting technology." The ability to hunt from a distance gave humans a distinct advantage over Neanderthals. We could hunt safely, giving us a higher chance of returning home to reproduce. This is a possible reason for the extinction of Neanderthals, modern humans most formidable rivals; we simply outhunted them

The one question that seems to be unanswered is a question of "What if?".  What if our shoulders had never fallen to their present position?  What if we were unable to throw a weapon from a distance and injure or kill our target?  Would we be the most dominant species on the planet? Would we still be living alongside Neanderthals?  Most importantly, would we still exist at all or would we have been replaced by another species better suited for life on Earth?  
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