09 AUG 2014 by ideonexus

 The Mother's Womb Tests the Viability of the Fetus

Given the invasive nature of pregnancy, it’s perhaps not surprising that the primate womb has evolved to be wary of committing to it. Mammals whose placentae don’t breach the walls of the womb can simply abort or reabsorb unwanted foetuses at any stage of pregnancy. For primates, any such manoeuvre runs the risk of haemorrhage, as the placenta rips away from the mother’s enlarged and paralysed arterial system. And that, in a sentence, is why miscarriages are so dangerous. It’s also w...
Folksonomies: pregnancy biology
Folksonomies: pregnancy biology
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24 DEC 2013 by ideonexus

 The Nominal Fallacy

The nominal fallacy is the error of believing that the label carries explanatory information. An instance of the nominal fallacy is most easily seen when the meaning or importance of a term or concept shrinks with knowledge. One example of this would be the word “instinct.” “Instinct” refers to a set of behaviors whose actual cause we don’t know, or simply don’t understand or have access to, and therefore we call them instinctual, inborn, innate. Often this is the end of the expl...
Folksonomies: cognition fallacy
Folksonomies: cognition fallacy
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Stuart Firestein explains why naming is not explaining.

21 JUN 2013 by ideonexus

 How Plants and Animals Survive in Their Environment

Plants and animals are separated by about 1.5 billion years of evolutionary history. They have evolved their multicellular organization independently but using the same initial tool kit the set of genes inherited from their common unicellular eucaryotic ancestor. Most of the contrasts in their developmental strategies spring from two basic peculiarities of plants. First, they get their energy from sunlight, not by ingesting other organisms. This dictates a body plan different from that of ani...
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Animals spend energy to maintain an internally consistent state, while plants change their state in response to the environment.

24 APR 2012 by ideonexus

 Species Go Through the Same Stages as Individual Living B...

Just as in the animal and vegetable kingdoms, an individual comes into being, so to speak, grows, remains in being, declines and passes on, will it not be the same for entire species? If our faith did not teach us that animals left the Creator's hands just as they now appear and, if it were permitted to entertain the slightest doubt as to their beginning and their end, may not a philosopher, left to his own conjectures, suspect that, from time immemorial, animal life had its own constituent e...
Folksonomies: religion philosophy
Folksonomies: religion philosophy
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They grow, change, and die.

13 APR 2012 by ideonexus

 Amniotic Sac as Space Suit

The most fundamental innovation is the evolution of another fluid-filled sac, the amnion. in which the embryo floats. Amniotic fluid has roughly the same composition as seawater, so that in a very real sense, the amnion is the continuation of the original fish or amphibian eggs together with its microenvironment, just as a space suit contains an astronaut and a fluid that mimics the earth's atmosphere. All of the rest of the amniote egg is add-on technology that is also required for life in a...
Folksonomies: evolution terrestrial
Folksonomies: evolution terrestrial
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For life to use to evolve onto land.

16 SEP 2011 by ideonexus

 Mammals Produce Useless Yolks

Vestigial genes can go hand in hand with vestigial structures. We mammals evolved from reptilian ancestors that laid eggs. With the exceptions of the “monotremes” (the order of mammals that includes the Australian spiny anteater and duck-billed platypus), mammals have dispensed with egg-laying, and mothers nourish their young directly through the placenta instead of by providing a storehouse of yolk. And mammals carry three genes that, in reptiles and birds, produce the nutritious protein...
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Because they evolve from egg-laying reptiles, they have dead genes for producing yolks and even produce yolks in the placenta.

03 JAN 2011 by ideonexus

 Number of Bits for a Set of Encyclopedias are Minuscule C...

I have estimaged how many letters there are in a the Enclyclopaedia, and I have assumed that each of my 24 million books is as big as an Encyclopaedia volume, and have calculated, then, how many bits of information there are (10^15). For each bit I allow 100 atoms. And it turns out that all of the information that man has carefully accumulated in all the books in the world can be written in this form in a cube of material one two-hundredths of an inch wide--which is the barest piece of dust t...
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Feynman estimates the number of atoms neccessary for storing a set of encyclopedias, and then compares that to the amount of data included in a DNA string.