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Have humans managed to accelerate the evolution of a species?

Posted by Alexandra McGrorty in Science and Society - Best on Thursday, November 11, 2010 at 9:34 pm

The process of evolution or natural selection takes years naturally, and is carefully fine-tuned and passed down throughout generations. However, humans try to replicate evolutionary process to document how it occurs. They also tend to invade and intrude on the habitats of other species, which can cause organisms to adapt more quickly to survive sudden changes brought on by humanity. Have humans managed to accelerate the evolution of a species?

 In some instances, humans have been known to purposely speed certain controlled processes up enough for them to document them. One of the more famous examples of this was the experiments carried out by Richard Lenski, who has, since 1988, been conducting a long-term evolution experiment using the E.coli bacterium as his subject. However, certain things (e.g. climate change) are accelerated by accident, with alarming and potentially harmful results. 

An example of this accidental acceleration was discussed in a UK Telegraph article titled "Human fishing and hunting accelerating evolution of species". By over harvesting some fish species at their most mature age and level of development, humans are causing certain fish species to change their sizes, and this is at a much more rapid rate than would happen naturally. Dr. Chris Darimont, a post-doctoral researcher in environmental studies at the University of California was quoted as saying "The pace of changes we're seeing supercedes by a long shot what we've observed in natural systems, and even in systems that have been rapidly modified by humans in other way. As predators, humans are a dominant evolutionary force."

overfishing-thousands-of-pounds-of-jack-mackerel-noaa-images

In his book "The Botany of Desire", Michael Pollan discusses the Semper Augustus (a rare and prized tulip) and Dutch "tulipmania" of the 17th century. This was a brief but intense tulip obsession in Amsterdam. It was one of the first instances of humans using natural selection to purposely change the appearance of an organism. A blight had been observed changing the colors of tulip petals, and soon a multicolored tulip became a coveted item. Farmers were introducing this blight to their tulips, which would ultimately kill the crop, but made the flowers beautiful and desired. Tulips were sold for outrageous amounts of money and a full-out craze ensued, until the market for the prized flower collapsed a few years later. 

Semper_Augustus_Tulip_17th_

Mankind has accelerated change in other species and organisms. While they may not have induced complete evolutionary change, they have certainly accelerated the rate of natural selection. This has been done both purposefully, with the intent and purpose of changing features or adding or eliminating different traits, such as with the tulips, or other examples, like dog breeding. This has also been done accidentally, for example some released or escaped pets caused an explosion of Burmese pythons in Florida, which changed biological diversity and natural evolution.  Possibly, sometime in the future, mankind will be able to accelerate actual evolution in its quest to understand nature and have concrete theories.

Tags: Q1 BM, q1, benchmark, evolution, Best, scisocE
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Why do humans and monkeys have such distinct characteristics?

Posted by Taniera Reid in Science and Society - Best on Thursday, November 11, 2010 at 9:24 pm

If humans were evolved from monkeys, why don't we have more similar physical characteristics? In the diagram of evolution, chimps are the most closely related organism to humans. According to National Geographic, scientist’s found that humans are 96 percent similar to the great ape species. Scientist Frans de Waal at Emory University states, “Darwin wasn't just provocative in saying that we descend from the apes—he didn't go far enough." He also states, "We are apes in every way, from our long arms and tailless bodies to our habits and temperament." Scientists have actual proof of the genetic relationship between human and chimp.


Humans and chimps have a high degree of genetic similarity.
Proteins are usually responsible for organism’s anatomical, psychological and behavioral characteristics.

The African Wildlife Foundation informs us that chimpanzees’ use of “sticks to collect ants and termites from their nests, and rocks to smash open nuts” draws a relationship between a human and chimp’s ability use “cognitive thinking to problem solve.” Similarities are drawn also in physical characteristics. The chimpanzee is known to be “Noisy and curious, intelligent and social” just like humans. The percentage of DNA identity between human and chimp is extensive.  However, the percentage is not 100% leaving room for physical distinctiveness between the two organisms.  Humans and chimps have a strong facial resemblance. According to the American Museum of Natural History, humans and chimps descended from the same ancestor species six or seven million years ago. The DNA of both organisms, passed from generations, changed. Many of these DNA changes led to changes in behavioral and physical appearance.

 

 

For more information, visit:

1. http://www.amnh.org/exhibitions/permanent/humanorigins/past/dna.php

2. http://news.nationalgeographic.com/news/2003/05/0520_030520_chimpanzees.html

3. http://www.associatedcontent.com/article/13842/the_similarities_and_differences_between.html

4. http://news.nationalgeographic.com/news/2005/08/0831_050831_chimp_genes.html

5. http://www.awf.org/content/wildlife/detail/chimpanzee

 

I&chimp-1
I&chimp-1
Tags: evolution, Best, scisocE
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Why tamper with evolution by protecting endangered species?

Posted by Mckelly Timothy in Science and Society - Best on Thursday, November 11, 2010 at 9:01 pm

It is said that extinction is a natural occurrence in evolution. Even though this is true, scientist believe that we should still save some species because they are dying before evolution can happen. The extinction of just one species can have a drastic impact on many other species. The only way protecting endangered species could be considered tampering with evolution is by killing species faster than evolution. As said by PBS, “No species exists in a vacuum”, no one species is isolated so every species has an effect on the other.

In today’s society there are many organizations working to save endangered species. These organizations realized that all species play a role in another’s life. If we were to lose a large number of one species there will be no food for the species that feed on them. Which would lead to the death of several species until we are all gone.

Many think of saving endangered species as tampering with evolution as said by Sheila Conant, Professor, and Department of Zoology University of Hawaii.  She believes that the endangerment of species is a natural process. She says this because a majority of the time species becomes endangered because their habitat has inadequate food quality or amount. This lowers the chances of an animal’s reproduction, and survival.

When we move an animal for instance moving polar bears to America because the are endangered that is an example of tampering with evolution because we are removing the species from its natural habitat, which is tinkering with its food, and natural reproduction abilities.

 

 

Questions

 - Since we believe animals evolve, why  aren't new species with similar but better characteristics created from evolution before extinction occurs?

- Is it possible to speed up the process of evolution?

- Do species become extinct not just because they can't survive in the present conditions but because they have no chance of survival in the future ?

 

Sources
http://www.pbs.org/wgbh/evolution/library/faq/cat08.html#Q03
http://jhered.oxfordjournals.org/content/101/4/437.abstract
http://www.jstor.org/pss/1310848


http://www.ncbi.nlm.nih.gov/pubmed/20332163


http://evolution.berkeley.edu/evolibrary/article/0_0_0/evo_02

Tags: Best, evolution, scisocE
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The Evolution of a Penguin

Posted by Narcissa Haskins in Science and Society - Best on Thursday, November 11, 2010 at 7:18 pm

           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
prehistoricpenguin
Penguins
Penguins
Tags: scisocE, Best, evolution
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How has the stereotypical role of a women developed an evolutionary basis?

Posted by Jasmine Harris-Foster in Science and Society - Best on Thursday, November 11, 2010 at 4:57 pm

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>.

Tags: scisocE, Best, evolution
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How has the shape of the human shoulder propelled us to the top of the animal kingdom?

Posted by Taylor Valentine in Science and Society - Best on Thursday, November 11, 2010 at 2:16 pm

​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
Ape Shoulder
Human 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?  
Tags: scisocE, Best, evolution
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