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Why do men have nipples?
Rough draft better
Chris Cassise
Why do men have nipples?. It’s the kind of question that doesn’t need to be answered but should be interesting to find out why they are there. It’s understandable for women to have nipples because it is the distributor for the breast milk to feed a newborn baby but a man, what does he need it for? According to Darwin’s theory on natural selection, it is theorized that men shouldn’t have nipples because during natural selection, the undesirable traits in the male/female body gradually lose their parts they don’t need over time. This would make sense as to why men have nipples; the process must not go through natural selection obviously since there must be a significant reason for it being there. A great example was the appendix, which now a useless part of our bodies was a part of the digestive track making it significant component. [1]
Men have nipples because it follows part of a female template since both sexes have similar tissue and body parts. Since this is confirmed that we share parts, it isn’t hard to understand why men just have nipples. When breasts grow abnormally on men it is called gynecomastia, which is the enlargement of breasts. So the question is simple surprisingly, Men and women follow the same template and nipples are just created no matter what sex you are and the chromosomes figure out if they will be functioning or non functioning in the process of knowing if they are going to be a man or woman. Its the effect of genes, in which the Y chromosome and hormone testosterone that changes the embryo. The idea of shared genetic basis of two traits is known as genetic correlation. Genetic correlation is “the proportion of variance that two traits share due to genetic causes.”[3] The evolutionary default is for males and females to share characters through genetic correlations.[4] Testosterone promotes the growth of the penis and testicles in men and since nipples are there before this process begins, they inhabit. Some genetic scientists have noted through this article that if nipples were harmful for the male body, they would have disappeared over time.
Source:
[1] http://www.buzzle.com/articles/appendix-function.html
[2]http://menshealth.about.com/od/conditions/a/Nipples_Men.htm
[3] http://en.wikipedia.org/wiki/Genetic_correlation
[4] http://www.scientificamerican.com/article.cfm?id=why-do-men-have-nipples
How did diseases come about through evolution; And how are they evolving currently?
Diseases came about throughout evolution largely from the results of
microorganisms; these microorganisms are specifically called microbes. Microbes
are microorganisms that cause disease or fermentation. At a point in time
microbes were contained to certain locations, meaning that at a point of time
they didn’t spread very much. When humans begin making the climb toward
civilizations, by making long trips, creating long distance trade, and also
exploring different geographic sections of the world. Microbes begin attacking
them, so it’s safe to say, that through cultural expansion diseases have
evolved. It is said that the spread of microbes modernly increased through the
European Industrialization and colonization.
This lead to the antibiotic era, this was an era when antibiotics begin to develop. In this era at a point in time, antibiotics begin to be misused and overused. At that time they didn’t know that antibiotics were only effective against bacterial infections. So this did more harm than good, because by people overusing antibiotics, microbes became smarter making immune to them. Not only did microbes become resistant they started creating strains that were more harmful. The the Antibiotic Era also led to the misuse and overuse of antibiotics used to treat very harmful infections, like the common cold, and influenza (flu). The overuse of antibiotics helped these infections and diseases become antibody resistant which is what scientist and doctors are dealing with currently.
In modern society our way of dealing with these issues are by using
vaccination, or by trying to cure them straight out. But by giving vaccinations
for infections like diphtheria, chicken pox, polio, tetanus, and measles, we
may be helping in the current situation, but at the same time producing strains
of antibody resistant microbes. In theory this may be detrimental to our generations in the years to come. As far as scientist and doctors trying to cure
diseases right from the start, there have been some issues following this as well. For example
when scientist and doctors tried to stop the spread of malaria with using
modern antimalarial medicine, the parasites that malaria contained, revolted
against it, because it became immune to the medicine, but it also created more
dangerous strands of parasites. This led to mutation of genes, which birthed
even more harmful diseases such as Sickle Cell Anemia, Thalassaemias, Duffy
Antigens, G6PD, and HLA and interleukin-4. Allow this is an example of just one example, this is an issue that follows the process of curing the most prominent diseases know to man, such as HIV/AIDS, and cancer. Bacteria is just becoming to smart...
In conclusion to put it simply as humans evolved with nature, so did microorganisms, and parasites. Which are still evolving as I write this blog. The real question is how will the evolution of smarter and more efficient humans lead to better engineering of preventive medicines?
Sources:
www.unmpress.com/more/0826330657.pdf
http://online.wsj.com/article/SB10001424052748704454304575081613327728110.html
http://www.cdc.gov/MALARIA/
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1224522/?tool=pmcentrez
The Addictive Personality.
It has long been asked if there is such thing as an Addictive Personality. As you’ve grown up perhaps you’ve noticed some of your friends have become dependent on substances like caffeine or nicotine. But is this just a personality trait, or something more? Research has shown that it could be rooted in one’s DNA. According to research done at the University of Utah, an ‘addiction gene’ wouldn’t mean that someone is bound to become addicted, but rather “it may be harder for people with certain genes to quit once they start.”
In recent studies, and Alcoholic
gene, DRD2, “was present in more than two-thirds of 35 deceased alcoholics,
whereas it appeared only in one-fifth of 35 deceased non-alcoholics.”
This confirms that if a parent is an alcoholic, it is more likely for their
children to be alcoholics as well.
According to Web MD, the genetic trait is considered a deficiency. It
seems to have no contributing factor to our species survival. Additionally no scientist
has presented a strong theory on why the gene developed in the first place,
beside it being a random genetic mutation.
Evolution of Venomous Snakes
There are many types of venomous animals like the lizards,
scorpions, even 
the male duckbilled platypus. But my main focus for this blog
are snakes. There are more than 2,200 species of poisonous and venomous snakes
in the world. Snakes lost both arms and legs due to grassy and subterranean
habitats, but evolution has handed snakes the ultimate weapon: venom. How did
they evolve into venom-injecting beast and how is venom still evolving into
society today?
Snakes emerged during the Cretaceous period from lizards, but Dr Bryan Grieg Fry at the University of Melbourne believes, "that almost all snakes share a common, venomous, ancestor". Venomous snakes have similar classes of protein in their venom, suggesting that in the vast difference of habitats, snake’s venom derived from a common origin.
Further Questions:
What other types of medicine can venom be substituted in?
Did venomous and poisonous snakes also evolved from the same ancestor?
Which venom is the most potent?
Links:
http://www.independent.co.uk/news/science/whats-your-poison-527683.html
http://www.fathom.com/course/10701017/session2.html
http://animals.howstuffworks.com/snakes/snake4.htm
http://www.animalcorner.co.uk/venanimals/ven_about.html
http://www.popsci.com/scitech/article/2008-03/evolution%E2%80%99s-most-effective-killer-snake-venom
http://evolutionblog.blogspot.com/2005/04/evolution-of-snake-venom.html
Snakes emerged during the Cretaceous period from lizards, but Dr Bryan Grieg Fry at the University of Melbourne believes, "that almost all snakes share a common, venomous, ancestor". Venomous snakes have similar classes of protein in their venom, suggesting that in the vast difference of habitats, snake’s venom derived from a common origin.
Venom itself also evolved, its
toxins and proteins being reborn from other proteins in tissues throughout the
snake’s body. snake-venom toxins were derived originally from proteins
in the brain, eye, lung, heart, liver, muscle, mammary gland, ovary and testis.
By tweaking the proteins from other body tissues, snakes developed a way to
create more specific and highly potent toxins.
Venom is still evolving today in medicine, having a beneficial effect on the body. For example, some poisons reduce blood pressure so quickly that the victim dies. But by changing and reproducing some components in venom, scientists can make a drug that reduces blood pressure.
Further Questions:
What other types of medicine can venom be substituted in?
Did venomous and poisonous snakes also evolved from the same ancestor?
Which venom is the most potent?
Links:
http://www.independent.co.uk/news/science/whats-your-poison-527683.html
http://www.fathom.com/course/10701017/session2.html
http://animals.howstuffworks.com/snakes/snake4.htm
http://www.animalcorner.co.uk/venanimals/ven_about.html
http://www.popsci.com/scitech/article/2008-03/evolution%E2%80%99s-most-effective-killer-snake-venom
http://evolutionblog.blogspot.com/2005/04/evolution-of-snake-venom.html
Have humans managed to accelerate the evolution of a species?
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."
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.
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.
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."
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.
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.
Why do humans and monkeys have such distinct characteristics?
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
Why tamper with evolution by protecting endangered species?
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
- 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
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.htmlhttp://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
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>.
