Paul Revere by Cyrus Dallin, North End, Boston

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Seen on Boston Common Today

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Fact: Not a single Nazi was the victim of vehicular homicide in Boston today.

Sunday, December 21, 2014

Sunday Science Blog





SCIENCE FYI: COULD A VIRGIN BIRTH EVER HAPPEN?IF YOU’RE A MAMMAL, NO. BUT IF YOU'RE NOT...


"Virgin birth, known to scientists as parthenogenesis, appears to be rather common in the animal kingdom. Many insects and other invertebrates are capable of switching between sexual and clonal reproduction. Among the vertebrates, virgin births have been documented in at least 80 taxonomic groups, including fish, amphibians, and reptiles. 

But humans and our fellow mammals provide a notable exception. So far as anyone can say—and there are a few gaps in the data, notably the platypus—no mammalian species is capable of giving birth without a father. So what stands in the way? First, a mammal’s egg cell usually won’t divide until it receives a signal from the sperm. Second, most mammalian eggs have only half the number of chromosomes necessary for development. If there isn’t any sperm, the embryo will end up with only half the DNA it needs to survive. Both of those barriers could potentially be overcome in the lab or through random mutation, but there is a third obstacle that probably can’t be. 

Under normal conditions, the DNA in both egg and sperm cells is altered such that some genes will be more active while others are suppressed. When the egg and sperm join to form an embryo, these imprints work in tandem, ensuring that all the necessary proteins are produced in the right amounts. If an egg cell starts reproducing on its own, without the sperm-cell imprint, the offspring won’t survive for very long."





DECEMBER 21, 2014       THE WINTER SOLSTICE





December Solstice: Shortest day of the year in the Northern Hemisphere

The December solstice is on either December 20, 21, 22 or 23. It is called Winter Solstice in the Northern Hemisphere, where it is the shortest day of the year. In the Southern Hemisphere, it is the Summer Solstice and the longest day of the year.

Solstice in December


 10 Things About December Solstice

 The Sun Stands Still 

The term solstice comes from the Latin word solstitium, meaning the Sun stands still. This is because on this day, the Sun reaches its southern-most (or northern-most during the June Solstice) position as seen from the Earth. It seems to stand still at the Tropic of Capricorn (and Tropic of Cancer during the June Solstice) and then reverses its direction. 


It's the First Day of Astronomical Winter 

In the Northern Hemisphere, astronomers and scientists use the December Solstice as the start of the winter season, which ends on the March Equinox. For meteorologists, on the other hand, winter began three weeks ago on December 1.





 

9 comments:

Infidel753 said...

Both of those barriers could potentially be overcome in the lab or through random mutation, but there is a third obstacle that probably can’t be.....If an egg cell starts reproducing on its own, without the sperm-cell imprint, the offspring won’t survive for very long.

This nevertheless suggest an interesting technological challenge. I wonder if a way could be developed for the merging of two egg cells to accomplish the same gene-expression effects as are naturally done via the merging of egg and sperm. That might someday enable lesbian couples to have children -- however tiresomely the fundies would screech about it.

BB-Idaho said...

Theologically, Jesus was born of Mary and the holy spirit.
Biologically, his DNA would be
fascinating.

Shaw Kenawe said...

Theologically Athena was born of Zeus, by emerging from his forehead. In full armor:

After a time, Zeus developed an unbearable headache, which made him scream out of pain so loudly it could be heard throughout the earth. The other gods came to see what the problem was. Hermes realized what needed to be done and directed Hephaestus to take a wedge and split open Zeus's skull. Out of the skull sprang Athena, fully grown and in a full set of armour. Due to the way of her birth, she became the goddess of intelligence and wisdom.

Raised in the Catholic religion, I was taught by the nuns that Jesus "passed through Mary's side, like a vision," when he was born.

Here are other "miraculous birth" myths in the worlds' religions:

Hinduism: In the story of Krishna the deity is the agent of conception and also the offspring. Because of his sympathy for the earth, the divine Vishnu himself descended into the womb of Devaki and was born as her son,

Buddhism: The stories of Buddha’s unusual birth developed through the centuries. Two accounts cited by Boslooper tell of the descent of the future Bodhisattva from the "Tusita Body" into the mother’s womb, the appearance of the Buddha in the mother as a shining gem, and the accompanying wonders in the natural world.

Sufism: In 1440, the poet Kabir was also said to have been born of a virgin widow (a Hindu), through the palm of her hand.

Zoroastrianism: According to later tradition, Zoroaster's mother, Dughdova, was a virgin when she conceived Zoroaster by a shaft of light.


There are many more. The one described below is most interesting.

Shaw Kenawe said...

The belief in the conception of Horus by Isis is traced to the beginning of Egyptian history. Horus' conception and birth were understood in terms of the Egyptian doctrine of parthenogenesis, which was connected with the goddess Neith of Sais.


Many of the attributes of Isis, the God-mother, the mother of Horus; and of Neith, the goddess of Sais are identical with those of Mary the Mother of Christ."

Early Christian stories in the Apocryphal Gospels, which record the wanderings of the Virgin and Child in Egypt are similar to stories found on the Metternich Stela texts about the life of Isis.

Also, the pictures and sculptures of Isis suckling her child Horus are the foundation for Christian figurines and paintings of the Madonna and Child.

Infidel753 said...

Theologically, Jesus was born of Mary and the holy spirit.

Scientifically, it still kind of works if you take "holy spirit" as an euphemism for God's sperm. Dunno what the Pope would think of that idea.

After a time, Zeus developed an unbearable headache, which made him scream out of pain so loudly it could be heard throughout the earth. The other gods came to see what the problem was. Hermes realized what needed to be done and directed Hephaestus to take a wedge and split open Zeus's skull.

Remind me not to go anywhere near those guys if I get a headache.

The preference of so many religions for stories of birth somehow happening without sex is rather odd when you think about it. Maybe it reflects the sexophobia that seems to afflict most religions to some degree.

Shaw Kenawe said...

My guess, Infidel753, is that the ancients (the men) were probably fearful of the female's capacity for sex and sexual pleasure. Perhaps they wanted to be the sole owners of that power?

I do know the mixed messages I received growing up as a Catholic girl was that the Virgin Mother was to be our model for a wife, which meant, let's face it, no sex for the husband and bear only one child (but only by God?). According to Catholic theology, Mary never "knew" a man and because of her special role as the Mother of God, was even born without original sin -- she was thus referred to as "The Immaculate Conception."

Infidel753 said...

My guess, Infidel753, is that the ancients (the men) were probably fearful of the female's capacity for sex and sexual pleasure. Perhaps they wanted to be the sole owners of that power?

Very plausible. An exception which reinforces the hypothesis would be Shinto in ancient Japan, which was a more female-oriented religion (the top deity was the Sun Goddess, and Chinese visitors to Japan in the 3rd century reported that it was ruled by a sort of high priestess), and from what I know of Shinto mythology their deities did reproduce by normal sex, though the details were a bit odd by our standards.

The concept of males being frightened or repulsed by female sexuality seems completely alien and bizarre to me, but it crops up in so many religions that it's obviously a real phenomenon. I'd feel very sorry for anyone still plagued by such a mental aberration, and for anyone they wind up sleeping with.

BB-Idaho said...

The 'church fathers' formulated
various explanations resolving
the Immaculate Conception, Mother Of God in light of " “Is not this the carpenter, the son of Mary and brother of James and Joses and Judas and Simon, and are his sisters here with us?” Mark 6:3.
Contemporary Rabbis were known to
conjecture about the legitimacy
of Mary's son, "Let us imagine what a Jew–let alone a philosopher–might say to Jesus: "Is it not true, good sir, that you fabricated the story of your birth from a virgin to quiet rumours about the true and insavoury circumstances of your origins? Is it not the case that far from being born in the royal David's city of bethlehem, you were born in a poor country town, and of a woman who earned her living by spinning? Is it not the case that when her deceit was uncovered, to wit, that she was pregnant by a roman soldier called Panthera she was driven away by her husband–the carpenter–and convicted of adultery?" (Celsus, On the True Doctrine).
Origen (184-253)rebutted this strongly and all copies of the
work by philosopher Celsus were
destroyed. From this distant
point, we can only guess.

(O)CT(O)PUS said...

Whether conception is immaculate
Or conferred by ejaculate,
The preferred way is lewd and licentious.
Turning haploids into humanoids
Is sensuous and erogenous.
There’s nothing amorous or joyous
In parthenogenesis.