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Monday, July 6, 2015

Some Interesting Finds about Germ Cells and Sex Reversals


Sperm from stem cells
http://www.youtube.com/watch?v=PWDOdCIiuUA

Eggs from stem cells
http://www.npr.org/blogs/health/2012/10/04/162263750/scientists-create-fertile-eggs-from-mouse-stem-cells

http://guardianlv.com/2012/10/jd-stem-cell-discovery-will-allow-gay-men-to-create-their-own-eggs-for-surrogate-birth/

http://www.nationalreview.com/human-exceptionalism/329653/could-stem-cell-research-allow-man-become-mother

Genes that prevent sex reversals:

http://www1.umn.edu/news/features/2011/UR_CONTENT_346326.html
http://blogs.discovermagazine.com/notrocketscience/2011/07/20/one-gene-keeps-mickey-from-turning-into-minnie/

http://www.mrc.ac.uk/Newspublications/News/MRC006549

http://www.heraldsun.com.au/ipad/sex-change-trigger-gene-found/story-fn6bfm6w-1225964752675

Cases of sex reversals
http://www.ncbi.nlm.nih.gov/books/NBK1547/

http://omim.org/entry/154230

SRY may have evolved from SOX3
http://www.ncbi.nlm.nih.gov/pubmed/21183788

Homologues of the human reproductive system
http://en.wikipedia.org/wiki/List_of_homologues_of_the_human_reproductive_system

Scientific Inquiry is My Faith and Helps Me Know God



It seems many people have the following religious notions:
1) Doubting or questioning what others in your church teach you is evil.
2) Knowledge can be acquired simply by believing. Even if there is nothing logically linking that belief to reality it is true simply because it is your faith.

However being born and raised a physicist I have always believed these notions instead:

1) You should question everything. Even if there is reason to belief it. Even if there is evidence to believe it. Even if there is convincing proof to believe it you must still question it and not only ask the question, "Is there a way this can be true?" but the question, "Is there a way this can NOT be true?"

2) There is always a certain degree of uncertainty (and flexibility) in our knowledge. Knowledge is never 100% concrete but is derived objectively from analyzing evidence and testing ideas. While I do believe that belief or faith can lead us to discover what we must to do acquire knowledge or even convey to us directly ideas that after examining the evidence ring true, I do not believe that simply believing is a way to acquire knowledge.


Faith without scientific inquiry leads to believing that the earth is flat and the center of the universe, or that heaven is up in the sky somewhere. It leads to believing that a man named Noah put millions of species of prehistoric animals on his arc (which according to the bible wasn't big enough to hold a small fraction of even the animals that exist on Earth today), or that the dinosaurs died in the flood because they wouldn't fit on the arc.... and that dinosaurs and people somehow coexisted or that dinosaurs came from a different planet (because that's the only way we can twist the evidence to fit our beliefs). 


'Faith' leads people to believe that the hominid skeletons found in Africa are just fakes contrived by followers of Satan to deceive others. It leads people to believe that mater cannot be created or destroyed (but particle physicists do both on a daily basis--it is energy that endures--not mater). It leads people to believe that the earth is only about 6000 years old. 

Empty faith leads people to criticize the Big Bang theory because they don't even bother looking into what the theory actually is. They just belief what others of their faith told them (i.e. that the Big Bang theory says that everything came from nothing and that God doesn't exist) when in reality the Big Bang theory was largely derived from a paper written by a Catholic Priest (Monsignor Georges Lemaître) about the origin of atoms (The theory was originally criticized for being too religious because the idea of matter and our entire universe coming from light seemed to fit the description in Genesis a bit too well--especially if you look at the Hebrew meanings of the words that have been inaccurately translated to waters, expanse and firmament).

If you look at the evidence contrary to these false 'faith'-based beliefs you will discover that there is absolutely no relation to these false beliefs and reality.

Perhaps my religion is an uncommon one because my religion does not use faith and belief as a reason to blind myself to reality. My religion is one where faith guides me to discover reality. It guides me to search, to seek, to study, to discover evidence, to question everything, to examine my own beliefs periodically and eliminate those beliefs that don't match up with the evidence and replace them with ones that do.

For me there is no difference between true science and true religion. The truth is the truth whether you believe in it or not, but it is my religion to seek out the truth and to continue to keep seeking for a better truth until perhaps some day after all is said and done and this life is over I will no longer see through a glass darkly (with uncertainty) but we see and know as God knows and be known as God knows me.

For in death we do not die, but our light returns to that LIGHT which governs all things. For light there is no uncertainty, there is no time, there is no space, there is only an exact and beautifully elegant eternal organization, but in this life light is exactly what we are uncertain about--it governs time, it defines space, it is the birth and death of material existence.

I thank God that every once in a while I am guided to see a glimpse of the light of eternity, and I thank God because physics makes those glimpses ever clearer.

Correcting Genetic Misconceptions: Gender is Genetically Complex




I read something like this in a genetics book about 6 years ago.  I found it very enlightening.  

The following is taken from http://www.isna.org/faq/y_chromosome

Does having a Y chromosome make someone a man?
Classification: FAQ
A lot of unintended harm happens when people assume a Y chromosome makes a person a boy or a man and the lack of a Y chromosome makes a person a girl or a woman. For example, one physician educator on our Medical Advisory Board had the challenging experience of trying to calm a 23-year-old patient who had just been told by a resident that she was “really a man” because the resident had diagnosed the patient as having a Y chromosome and complete androgen insensitivity syndrome (CAIS).
It is true that in typical male development, the SRY gene on the tip of the Y chromosome helps to send the embryo down the masculine pathway. But more than the SRY is needed for sex determination and differentiation; for example, women with CAIS have the SRY gene but lack androgen receptors. In terms of hormone effects on their bodies (including their brains), women with CAIS have had much less “masculinization” than the average 46,XX woman because their cells do not respond to androgens. 
Moreover, the SRY gene can be translocated onto an X chromosome (so that a 46,XX person may develop along a typical masculine pathway), and there are dozens of genes on chromosomes other than the X and the Y that contribute to sexual differentiation. And beyond the genes, a person’s sex development can be significantly influenced by environmental factors (including the maternal uterine environment in which the fetus developed).
So it is simply incorrect to think that you can tell a person’s sex just looking at whether he or she has a Y chromosome.
Want to know more? The following comes from ISNA’s Medical Advisory Board member Dr. Charmian Quigley:
SRY, discovered in 1989, is a small gene located at the tip of the short arm of the Y chromosome. So what does it do? Actually, like all genes, it does nothing except to act as a blueprint for a protein. In this case, the protein of the same name does funky things to DNA, like bending it and unwinding the 2 strands, so that other proteins can get in and attach themselves to other genes that are then turned on. So how did this gene get its reputation (and its name) as the “sex determining” gene?
As is pretty common in the world of genetics, this was because of some errant mice. Researchers in England took a laboratory-made copy of this gene and inserted it artificially into a female (XX) mouse embryo at a very early stage of development. The mouse was “converted” from female to male, so the gene must have been responsible – right? Well, maybe not. A few years later, a similar gene was found on human chromosome 17. When the important part of this gene was inserted into a female mouse embryo, the same thing happened. Voila! A male.
So now we have 2 genes that can turn a female into a male, and one of them is not located on the Y chromosome! How can that be? It turns out that SRY is probably just a facilitator that allows a more critical gene (or genes) to function, by blocking the action of another opposing factor. Can the magic of genetics do the opposite – turn a male into a female? Indeed it can. A gene on the X chromosome (the chromosome one typically associates with “femaleness”) called DAX1 when present in double copy in a male (XY) mouse, turns it into a female.
So now we have genes on the Y that can turn females with XX chromosomes into males and genes on the X that can turn males with XY chromosomes into females… wow! Maleness and femaleness are NOT determined by having an X or a Y, since switching a couple of genes around can turn things upside down.

In fact, there’s a whole lot more to maleness and femaleness than X or Y chromosomes. About 1 in 20,000 men has no Y chromosome, instead having 2 Xs. This means that in the United States there are about 7,500 men without a Y chromosome. The equivalent situation - females who have XY instead of XX chromosomes - can occur for a variety of reasons and overall is similar in frequency.
For these 15,000 or more individuals in the US (and who knows how many worldwide), their chromosomes are irrelevant. It is the total complement of their genes along with their life experiences (physical, mental, social) that makes them who they are (or any of us, for that matter). The last time I counted, there were at least 30 genes that have been found to have important roles in the development of sex in either humans or mice. Of these 30 or so genes 3 are located on the X chromosome, 1 on the Y chromosome and the rest are on other chromosomes, called autosomes (on chromosomes 1, 2, 3, 4, 7, 8, 9, 10, 11, 12, 17, 19).
In light of this, sex should be considered not a product of our chromosomes, but rather, a product of our total genetic makeup, and of the functions of these genes during development.

Thursday, February 5, 2015

A Solution to Global Warming: Humans Need to be Eaten


Global warming is a huge topic of debate and has been for decades, but what is the real problem here? Pollution. What causes pollution? Humans.

Lets just look at some figures here:

There are just over 7 billion people on earth.
As of 2010 human beings were generating in access of 33 billion metric tonnes of carbon emissions per year.

This means that per capita humans generate at least 4.7 metric tonnes of carbon emissions--that's over 10 trillion pounds of carbon per year per person!!!

 That's more CO_2 per person per year than the entire human race produces per year through respiration (breathing)!

So, this is only a tiny fraction of the pollution human beings cause. We also produce so much garbage we make new islands and mountains out of it (literally). We contribute to ecological pollution as well by destroying or altering natural habitats and over exploiting plant and animal life.

The fact of the matter is our current rate of pollution is quickly killing our planet and will lead to the eventually demise of humanity by one simple principle: if we can't eat, breath or drink then we will die.

Now let's consider the fact that human beings are reproducing far beyond any other species of mammal at an exponential rate that simply has no comparison:


In studying population growth in my calculus classes I've learnt an extremely important principal: in order to establish a stable population there must be predation. The sad fact of the matter is human population growth alone is enough to ensure the untimely demise of our little green planet. Therefore I must conclude that the only way to save the Earth and the human race is to control human population growth.  Sure we could institute reproduction limiting laws like in China, but that leads to so many tragic stories of abandoned baby girls. Sure we could educate our teens about safe sex and hand out condoms at school, but it's not going to help because guys think "it just feels better" without one. Sure we could do any number of things to try to limit population growth but even the 11 million Mormons out there are more than enough to keep the human race growing out of control and ensure our destruction.

I must conclude that there is only one solution to the Global warming problem:



Predation! Yes Predation! Humans simply need a worthy predator. Yes, the key to our human survival is to be eaten by something else! The only way to limit human consumption is to be consumed. Well, unfortunately there don't seem to be predators out there that like to snack on humans at least not at a rate that would even put a dent in our population growth. Maybe we could genetically engineer some monstrous creature that eats people, but I doubt that could work--we'd just kill it before it had the chance to grow.


Perhaps in the future our race will survive as a result of an alien invasion where the aliens like to eat people and our survival will be ensured much like we humans have ensured the survival of cattle because we love to eat them. Nah, never going to happen unless they come from another dimension or have somehow mastered light speed travel or something better.

 Fortunately for us there are already predators that feed on humans and kill millions of us per year. The most powerful predators against humans are often overlooked because they are so dang small: bacteria and viruses.



In all of recorded human history the only thing that has ever put a dent in the human population growth chart was the Plague: a simple bacteria.  Even with all the death it caused we managed to overcome it, but could the future of humanity actually depend on bacterial or viral population control? I mean, it seems like it's either going to be something like that or a Soilent Green sort of thing and I'd personally rather be eaten by genetically engineered super bacteria than other humans....


Sources:
http://co2now.org/Current-CO2/CO2-Now/global-carbon-emissions.html
google.com
https://micpohling.wordpress.com/2007/03/27/math-how-much-co2-is-emitted-by-human-on-earth-annually/

Tuesday, December 16, 2014

The 4 Types of Biological Sex

 What Determines Human Sex?

Most people are taught from an early age that sex is a simple matter of either being a boy or a girl. We are taught that girls have vaginas and boys have penises. It all seems pretty straight forward. Most of the world has based our entire social structure around whether we are male or female and gender is an important role in many religions and religious practices across the world. There are even socially and legally imposed limitations or benefits based on our sex--for example: women being limited in combat roles in the military or men being ostracised for shaving their legs. Women often make less money for doing the same jobs as men—even if they are more qualified than their male counterparts.

In society sex seems pretty straight forward for most of us, and most of us feel like we have a firm grasp of what biologically makes us male or female. However, the unfortunate truth is most of us have absolutely no idea. Biologically speaking there is no distinct binary grouping of male and female—the biology is so much more complex than that. There isn’t one thing that biologically determines sex there are actually four different main categories that determine sex.  

There are 4 Types of Biological Sex (each separated into the subcategories male, female, intersex, and neuter):

  • Genital Sex (vagina, penus, intersex, neither)
  • Gonadal Sex (ovaries, testes, ovotestis, neither)
  • Genetic Sex (XX/XY, SRY+ or SRY-, SOX9/FOXL2, etc.)
  • Brain Sex (determined by brain structure, function and identity: male, female, in between, or neither)

Genital Sex is the type of sex most individuals are familiar with—well because we can see them from the outside. Genital sex is determined by the appearance—if the genitals look stereotypically male (having a penis and scrotum) then the person has a male genital sex. If a person looks stereotypically female—having the outer female anatomy: labia, clitoris, vagina etc. the person has a female genital sex.

Some individuals however are born with a genital sex between that of male and female. These individuals are intersex. Some people who are otherwise female (having ovaries, and other female anatomy) are born with penises as in various forms of clitoromeglia and hormone metabolic disorders (see http://en.wikipedia.org/wiki/Inborn_errors_of_steroid_metabolism). Some individuals who have testicles and are male in other ways have part male and part female genitalia which varies from being born with a tiny penis, being born with an enlarged clitoris and no vagina to being born with just about any combination of external male and female genitalia. In rare cases individuals are even born with a vagina and a functional penis. 5-alpha-reductase deficiency is just one of many of these type of conditions (see http://en.wikipedia.org/wiki/
5%CE%B1-Reductase_deficiency). AIS is another one of these conditions (see http://en.wikipedia.org/wiki/Androgen_insensitivity_syndrome). I have only mentioned a few, but there are hundreds of conditions that result in intersex conditions in genital sex.

Some individuals are born missing genital anatomy. Some women are born missing a vagina or a proper vaginal opening. Some genetic males are born missing their genitals and parts of their lower abdomen entirely (see http://www.newsweek.com/lab-grown-vaginas-give-
new-hope-245851 and http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1421517/). These individuals are complete or partial neuter when it comes to genital sex.
Gonadal Sex is determined by having ovaries or testicles, some mix of both, one of each or neither. ‘Common knowledge’ argues that gonadal sex and genital sex are the same, but biological reality that the lives of thousands across the world have demonstrated definitely. As discussed earlier there are hormone metabolic disorders where individuals who have ovaries are born with penises or some degree of external male anatomy. Congenital adrenal hyperplasia is one of these such cases (see http://en.wikipedia.org/wiki/Congenital_adrenal_hyperplasia_
due_to_3%CE%B2-hydroxysteroid_dehydrogenase_deficiency). In the case of CAIS (complete androgen insensitivity syndrome) individuals with testicles who are genetically male are born with complete external and sometimes partial internal female anatomy. CAIS is caused by a malformed androgen receptor gene--this makes it so their bodies can not use androgens properly (such as testosterone). These individuals almost always have female identities and a female brain sex (see http://en.wikipedia.org/wiki/Complete_
androgen_insensitivity_syndrome). Another similar condition is XY gonadal dysgenesis or Swyer Syndrome—where a genetic male fails to develop testicles and develops female external genitailia and a normal uterus and fallopian tubes, but no ovaries. Amazingly even though these individuals are genetically male (they have XY chromosomes) they can menstrate and can even get pregnant with a donor egg (see http://en.wikipedia.org/wiki/XY_gonadal_dysgenesisand http://ghr.nlm.nih.gov/condition/swyer-syndrome).

Some individuals are born with gonads somewhere between male or female (called ovotestes because they are a mixture of ovarian and testicular tissue) and other individuals are born with one testicle and one ovary. XX/XY tetragametic chimerism is one condition that causes cases like these (see http://en.wikipedia.org/wiki/Tetragametic_chimerism#Tetragametic_chimerism).
Other individuals of both genetic sexes are born completely missing ovaries or testicles (see http://en.wikipedia.org/wiki/Penile_agenesis_and_testicular_agenesisand http://en.wikipedia.org/wiki/Gonadal_dysgenesis).

Genetic Sex is by far the most complicated classification of sex. Those who studies biology in high school in the past 50 years probably know that having XY chromosomes means you are male and having XX chromosomes means you are female, but unfortunately it’s not that simple either. The XX or XY rule seems to work out most of the time but there are many exceptions that affect the lives of thousands across the globe. I have previously mentioned several conditions where an individual develops external genitailia and identity that does not match their genetic sex such as CAIS and Swyer Syndrome and many steroid metabolism disorders, but there are a lot of genetic issues we still haven’t considered.

I will proceed by describing several genetic factors and conditions that demonstrate that genetic sex is far more complicated than XY or XX chromosomes: 
Types of gender genetic :
  • Synthetic germ cells (made from skin cells altered into stem cells)
  • Other gender/sex related genetic markers lie outside X and Y Chromosomes

46,XX / 46,XY Tetragametic Chimerism:
Tetragametic Chimerism happens when two fertilized eggs that would normally develop into fraternal twins collide and merge growing into one body with two distinct sets of DNA. XX/XY Chimerism is when those twins would have developed as opposite sex. The result is a person who is genetically part male and part female. The individual may develop with normal male genitailia or normal female genitailia or a mix of both. The brain may develop from the male DNA or the female DNA or a mix of both—so might the rest of the organs and tissues. Here are several case studies:

XX/XY Chimera with normal male phenotype detected by two skin colors:
XX/XY Chimerism in a phenotypically normal male
Pregnancy of XX/XY Chimera with an ovotesti
xx/xy chimera born with a mix of sex organs
XX/XY chimera born as a phenotypically normal baby girl
xx/xy chimera with normal male phenotype
xx/xy fertile chimera--normal female phenotype and organs and 99% XY DNA
xx/xy found in amniotic fluid, but a normal female with XX dna is born
xx/xy normal functioning female

XX/XY, XXY/XY, XXY/XX Mosaicism:
Mosaicism is similar to Chimerism in that the individual has two cell lines (two different sets of DNA) however in Mosaicism they originated from the same fertilized egg.  The difference occurs when there is an error in DNA replication during cell division. Some of the cells develop normally but some pass along the altered genes.

Here is an interesting case study of a mosaic born from one sperm and one egg with normal XX and normal XY DNA

Klinefelter Syndrome (47 XXY, 48 XXYY, 48 XXXY, 49 XXXXY)
Klinefelters Syndrome is a condition where someone is born with a Y chromosome but more than one X chromosome. Contrary to popular belief individuals with Klinefelters can sometimes have children. Individuals with Klinefelters are usually raised as male because of their external genitailia and identities, but in rare cases they have female identities and some degree of physical feminization (see http://en.wikipedia.org/wiki/Klinefelter_syndrome)

XY SRY- females:
This is a condition where an otherwise genetic male with XY chromosomes is born with a defective Y chromosome that is missing the SRY gene sequence--this leads to the individual developing as a relatively normal, but usually sterile female. 

Here is an interesting case of an XXY SRY negative female who had children and even passed her XXY gene to her daughter:

XX SRY+ males:
This is a condition in which an otherwise genetically normal female is born with a defective X chromosome that has had the SRY gene sequence copied into it. This individual develops as a normal but sterile male.

And article comparing XX  SRY+ males with XXY males and females

FOXL2, DMRT1, WNT4, SOX9 Genes:
These genes maintain ovarian tissues and testicular tissue, meaning a defect in these genes or if they are shut off can lead to and XX individual developing testicular tissue or an XY individual developing ovarian tissue. (See:
Homozygous inactivation of Sox9 causes complete XY sex reversal in mice:

Unexplainable Genotype/Phenotype Cases:

This is a case study of a normal male (but infertile) but he is genetically female according to every known test. This and other research has demonstrated that there are genes that are important for sexual differentiation that are outside of the X and Y chromosomes.



Brain Sex is the most important factor in determining the biological gender of an individual. Unfortunately, brain sex is the type of sex people are usually least familiar with. Men and women not only think differently from one another the physical structure of their brains is different. The shape and function of the male and female brain develops in the womb and is influenced by the androgen (testosterone) and estrogen levels; however, it can also be influenced by genetic factors. There are many factors that can change the hormone balance in the womb and influence brain sex as a consequence.

A big difference between the male and female brain is the size and shape of the hypothalamus. The hypothalamus is the master gland that regulates hormone production in the body--including sex hormones. A female-shaped hypothalamus even sometimes attempts to regulate hormones to a female level, while a male-shaped hypothalamus attempts to regulate hormones to a male level. Studies in transsexuals and transgender individuals have shown that many of them have a hypothalamus shaped to match their gender identity--not their genital, gonadal, or genetic sex  (a transsexual is an individual with a gender identity and brain sex that does not match the other three types of sex--i.e. their body and genetics. This term should not be confused with the terms transvestite, or cross-dresser. Transsexualism is an actual inborn medical condition. Also, I should note that not all transgender individuals are transsexual. Transgender is simply a term that encompases a lot of different types of gender expression that go beyond conventional norms). These transsexual individuals often have irregular hormone levels compared to controls of their gonadal sex due to the function of the hypothalamus.

Here are a few of the many studies out there demonstrating that transsexuals have brain structures that match their identities, not their gonads:
Hormone disruptors - A hormone disruptor is a chemical that causes a change in the body’s normal hormonal balance. There are many hormone disruptors such as xenoestrogens (chemicals that act like estrogens) found in many plastics and many if not most personal care products. Pesticides, herbicides and fertilizers are hormone disruptors, along with millions of other products, food additives and medications out there. There are also many xenoandrogens (chemicals that act like testosterone). Hormone disruptors have been proven to cause intersex conditions and alteration of brainsex—they are one of the proven causes of transsexualism. DES is just one example of a medication that has been directly linked to altering the brain sex of a fetus of a pregnant mother often resulting in transsexual children (see http://en.wikipedia.org/wiki/Diethylstilbestrol).
There are also many natural factors that can disrupt the hormone balance of the womb and alter a developing fetus’ brain sex—such as stress, depression, anxiety, and trauma.

The hormone balance in the womb is not the only factor in determining brain sex. There are also genetic factors that can determine brain sex—even if the hormone balance is opposite from the resulting brain sex. XX/XY chimerism is one such case—where the child is born with a brain with XX or XY DNA and a body of the opposite genetic sex. In this case study artificial chimeras were made in quail where they grew female quail brains in male quail bodies—the resultant quail behaved more like female quail than male quail despite the fetal hormone levels. The quail showed female behavior and low male hormone levels (after maturation): http://www.pnas.org/content/100/13/7959.full



Brainsex is the only classification of biological sex that determines gender—A Proof Via Case Studies:

1. Genital Sex—Having a penis or a vagina does not determine gender:
  • Genetic males with Cloacal Exstrophy are usually assigned to female at birth because they are missing male genitalia. In this case study the gender identities of several of these individuals are studied showing that many of them identify as female and several of them as male (even though they now have female external genitailia): http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1421517/
  • The story of David Reimer is famous for disproving the idea that boys and girls simply are what we raise them to be. David was born a normal boy, but due to a circumcision accident he lost his penus. The doctor and his parents decided to have David surgically altered so he would have female genitailia. Despite David’s parents doing their best to raise him as a normal girl he grew up knowing from the start that he was a boy. (see http://en.wikipedia.org/wiki/David_Reimer).

2. Gonadal Sex—Ovaries or testicles do not determine gender:

3. Genetic Sex—Genetic makeup does not determine gender:
  • In this case study a phenotypically normal male (having full male genitalia and identifying as male) was tested to be genetically female according to all known DNA tests for genetic sex. He was sterile only because the Y chromosome is nessessary for sperm production: http://molehr.oxfordjournals.org/content/12/5/341.short

  • In this case study of an XX/XY tetragametic chimera she was completely phenotypically female (see looked completely female) and had only female reproductive organs and 99% XY DNA (i.e. she was 99% genetically male). She idetifies as female and was also able to bear children: http://humrep.oxfordjournals.org/content/16/1/56.short

4. Brain Sex—Brain Sex determines gender:
    In all of these case studies the only constant that determines an individual’s gender is what the individual identifies as. An individual’s gender identity is therefore determined by the sex of the brain (i.e. the brain structure).

Thursday, January 31, 2013

Buoyancy - What Floats?


Here's an easy science experiment for young children ages 2 and up.  All you need is a container of water, a pan to catch the water that spills out, a towel to wipe up and dry hands, a paper and pen, and five objects you are willing to get wet that fit comfortably inside the container.

This simple experiment helps kids learn how to perform and experiment, hypothesis and document their results (no writing required).

Make sure you help your child through each of the following steps:
  1. Have your child find five objects that can safely get wet that they do not know if they will float or not.
  2. Have your child draw a picture of each object in the first row.
  3. In the middle column have them form a hypothesis of whether the object will float in water or sink.  If they think it will float have them draw an up arrow.  If they think it will sink have them draw a down arrow.
  4. Have your child test each object one at a time and record their results with up and down arrows in the last column.
  5. Have you child circle each pair of arrows that does not match up and discuss with them why they think things didn't turn out how they thought.


After the experiment you can talk with your child about density.  (Density is the ratio of mass to volume or mass/volume).  In other words the heavier an object is and the smaller the space it takes up the denser the object is.  Objects that are denser than water sink.  Objects that are less dense than water float.

Wednesday, January 2, 2013

Number of Chromosomes does not Equate to Awesomeness


So, I just came across this thing above on facebook and I just felt like commenting on one thing it says: "Human beings have 46 chromosomes, 2 less than the common potato."

Yes it is true that potatoes usually (but not always) have 48 chromosomes, but what is the point of this statement?  It seems to be using this statement among others in an attempt to make our being human seem insignificant in the vast scheme of things.

This facebook post implies the following:

Human beings have less chromosomes than potatoes and are therefore less genetically complex and less important than potatoes.

This however is completely absurd and completely false!

Let's look at another example:  a carp has 104 chromosomes, but is a carp really more than twice as capable or twice as important as a human?

Actually chromosome numbers vary extensively from species to species.  The Adders-tongue (a type of fern) has the highest number of chromosomes of any known life form at 1440 (see wikipedia article).

The number of chromosomes is not a reflection of the genetic complexity of a species.  As far as DNA goes it's about quality not quantity.  Just as the computers of 1969 might have been the biggest baddest computers of all, a cheep cellphone of today has several thousands times the computing ability.

Yeah, it just kind of bugs me when people appeal to science to draw illogical conclusions.