Monday, December 24, 2012

Tricky spiders' web and 33 new species of trapdoor spider

Cobwebs are actually small feats of engineering.  Polymer scientists at the University of Akron have discovered that the common house spider can tailor the type of adhesive discs it uses to anchor its webs, making them stronger or weaker depending on where the cobwebs are situated and the anticipated movements of its prey.
Webs located up in the air, such as those on ceilings and vertical surfaces, tend to catch flying insects, which are moving at a greater velocity.  So the adhesive used in these is stronger – that way the web doesn’t come loose when it’s struck by an airborne object moving at a high rate of speed.  But when spiders build webs that are located close to the ground, they use less adhesive in the discs.  When an unsuspecting insect wanders into a web, the anchoring thread snaps away from the ground and – voila! – the spider’s dinner is left dangling helplessly in the air by a sticky silk strand.

The polymer experts were impressed by the sophistication of this trick.  “What we have also discovered is a key design principle,” said Ph.D graduate Vasav Sahni. “It’s not a question of the inherent chemistry of the glue, but how the same glue can have different degrees of adhesion.”

The Akron team have published the details of their study in the most recent issue of Nature Communications.


The discovery of 33 new species of sneaky trapdoor spiders boosts the total number described in one genus from seven species to 40.

Trapdoor spiders, which belong to the same suborder as tarantulas, are pretty badass. Instead of weaving webs, they build subterranean silk-lined burrows — and cap the burrow with a trapdoor. Then, hunkered down beneath the trap door, the spiders wait for an unsuspecting insect to trigger the trip lines.

“They’re sort of ambush predators,” said arachnologist Jason Bond, director of the Auburn University Museum of Natural History, and author of the study describing the new species, which appeared Dec. 19 in the journal ZooKeys. “They wait at burrow entrances at night, until some dull-witted insect comes over. Then they jump out, bite it, and take it to their burrow. This particular group, they pack its carcass down into the bottom of the burrow.”

Some of the newcomers have pretty fantastic names. Aptostichus barackobamai is named for Barack Obama. Aptostichus bonoi, which lives in Joshua Tree National Park, is named after U2 band member Bono. Aptostichus sarlacc? That’s basically the Tatooine spider. It lives in the Southern California desert, and takes its name from Boba Fett’s ground-dwelling tormentor. The Atomic Penn Jillette Trapdoor spider (Aptostichus pennjillettei) is from the old nuclear testing site near Mercury, Nevada.
Male Aptostichus barackobamai. Image: Jason Bond.
Female Aptostichus barackobamai. Image: Jason Bond.
Female Aptostichus aguacaliente. Image: Jason Bond.
Female Aptostichus atomarius. Image: Jason Bond.
Female Aptostichus chavezi. Image: Jason Bond.
Male Aptostichus miwok. Image: Jason Bond.
Female Aptostichus stephencolberti. Image: Jason Bond.
Trapdoor spider burrow, closed. Image: Jason Bond.
Trapdoor spider burrow, open. Image: Jason Bond.
One of the species in this newest batch, found near a relatively young, volcanic cinder cone close to Barstow, CA, is named after Bond’s daughter, Elisabeth. Living among the lava tubes that extend from the cone, Aptostichus elisabethae builds deep, elaborate burrows that extend multiple feet into the ground. Some of the other species burrow only a few centimeters beneath the surface. “I’ve always appreciated their engineering marvels,” Bond said, noting that the spiders continually reinforce their burrow walls with silk, and that some desert species maintain a routine of “winter cleaning,” leaving little piles of excavated material outside.

Tuesday, December 18, 2012

Mayan doomsday: Civilization collapse linked to climate change

Mayan doomsday
Mayan civilization collapse and climate change
  ***
Comalcalco was a major Mayan port city that was believed to have flourished between A.D 700 to A.D 900. Though others place it much older, and even perhaps older still, since the finds at Nakbe in the Petén, it may go back to 1000 BCE, and beyond. Since there was no rock quarry or stone to use in the area, they built the buildings out of bricks made of baked mud. The Maya raised HUGE structures made out of these bricks. That in itself makes this place unique to all the other Mayan locations. But, you see, the bricks have inscriptions on them.
The map of the Mayan Zone
Mayan ruins in Guatemala
 Where the rain forests of Guatemala now stand, a great civilization once flourished. The people of Mayan society built vast cities, ornate temples, and towering pyramids. At its peak around 900 A.D., the population numbered 500 people per square mile in rural areas, and more than 2,000 people per square mile in the cities -- comparable to modern Los Angeles County. 

This vibrant "Classic Period" of Mayan civilization thrived for six centuries. Then, for some reason, it collapsed.

The fall of the Maya has long been one of the great mysteries of the ancient world. 

The Rise and Fall of the Mayan Empire:
Sever, NASA's only archeologist, has been using satellites to examine Mayan ruins. Combining those data with conventional down-in-the-dirt archeological findings, Sever and others have managed to piece together much of what happene
From pollen trapped in ancient layers of lake sediment, scientists have learned that around 1,200 years ago, just before the civilization's collapse, tree pollen disappeared almost completely and was replaced by the pollen of weeds. In other words, the region became almost completely deforested.
 Without trees, erosion would have worsened, carrying away fertile topsoil. The changing groundcover would have boosted the temperature of the region by as much as 6 degrees, according to computer simulations by NASA climate scientist Bob Oglesby, a colleague of Sever at the MSFC. Those warmer temperatures would have dried out the land, making it even less suitable for raising crops.
Figure of a Maya priest.

Rising temperatures would have also disrupted rainfall patterns, says Oglesby. During the dry season in the Petén, water is scarce, and the groundwater is too deep (500+ feet) to tap with wells. Dying of thirst is a real threat. The Maya must have relied on rainwater saved in reservoirs to survive, so a disruption in rainfall could have had terrible consequences.
(Changes in cloud formation and rainfall are occurring over deforested parts of Central America today, studies show. Is history repeating itself?)
Using classic archeology techniques, researchers find that human bones from the last decades before the civilization's collapse show signs of severe malnutrition.
"Archeologists used to argue about whether the downfall of the Maya was due to drought or warfare or disease, or a number of other possibilities such as political instability," Sever says. "Now we think that all these things played a role, but that they were only symptoms. The root cause was a chronic food and water shortage, due to some combination of natural drought and deforestation by humans."
Throne 1 of Piedras Negras
A message from 900 A.D.: it's never too late to learn from your ancestors:
Using oxygen isotope dating on stalagmites taken from caves near various Mayan sites, scientists were able to determine precipitation levels in the area, and correlate these with known political records taken from Mayan stele and hieroglyphics.
They found, quoting materials supplied by UC Davis:
Periods of high and increasing rainfall coincided with a rise in population and political centers between A.D. 300 and 660. A climate reversal and drying trend between A.D. 660 and 1000 triggered political competition, increased warfare, overall sociopolitical instability, and finally, political collapse. This was followed by an extended drought between A.D. 1020 and 1100 that likely corresponded with crop failures, death, famine, migration and, ultimately, the collapse of the Maya population.
Temple of the Cross at Palenque; there is an intricate roof comb and corbeled arch

 Commenting on the finds from Central America, Bruce Winterhalder, from UC Davis' Native American Studies, bridges the centuries: "It's a cautionary tale about how fragile our political structure might be. Are we in danger in the same way the Classic Maya were in danger? I don't know. But I suspect that just before their rapid descent and disappearance, Maya political elites were quite confident about their achievements."

*Note: all pictures thankfully shared from various sources..

Wednesday, December 12, 2012

Scientists create new element 113: how large an atom nucleus could be

Element 113 is an atom with 113 protons in its nucleus -- a type of matter that must be created inside a laboratory because it is not found naturally on Earth. Heavier and heavier synthetic elements have been created over the years, with the most massive one being element 118, temporarily named ununoctium.
But element 113 has been stubbornly hard to create. After years of trying, researchers at the RIKEN Nishina Center for 
Accelerator-Based Science in Japan said today (Sept. 26) they finally did so. On Aug. 12, the unstable element was formed and quickly decayed, leaving the team with data to cite as proof of the accomplishment.

Elements starting with hydrogen, with the atomic number of 1, through to plutonium, 94, exist naturally. Those from 95 through the 116 have been created and confirmed, excluding those with the atomic numbers of 113 and 115.

How 113 Was Made
Kosuke Morita and his team collided zinc nuclei (30 protons) with a thin layer of bismuth (83 protons) to form nuclei with 113 protons. The nuclei underwent alpha decay, turning element 113 into element 111, 109, 107, 105, 103 and element 101, Mendelevium.
The RIKEN Linear Accelerator Facility outside of Tokyo, in which element 113 has been discovered and confirmed (Photo: RIKEN)

"For over nine years, we have been searching for data conclusively identifying element 113, and now that at last we have it, it feels like a great weight has been lifted from our shoulders," Kosuke Morita, leader of the research group, said in a statement. 

If confirmed, the achievement will mark the first time Japan has discovered a new element, and should make Japan the first Asian country with naming rights to a member of the periodic table. Until now, only scientists in the United States, Russia and Germany have had that chance.

"I would like to thank all the researchers and staff involved in this momentous result, who persevered with the belief that one day 113 would be ours," Morita said. "For our next challenge, we look to the uncharted territory of element 119 and beyond."
Dr. Kosuke Morita of the RIKEN Nishina Center for Accelerator-based Science (Photo: RIKEN)

Scientists are continually trying to create bigger and bigger atoms, both for the joy of discovery and for the knowledge these new elements can offer about how atoms work.

Most things in the universe are made of very simple elements, such as hydrogen (which has one proton), carbon (six) and oxygen (eight). For each proton, atoms generally have roughly the same number of neutrons and electrons. Yet the more protons and neutrons that are packed into an atom's nucleus, the more unstable the atom can become. Scientists wonder if there is a limit to how large atoms can be.
The decay chain for ununtrium-278, as confirmed by the known alpha decay of Db-262 into Lw-258, and that of Lw-258 into Md-254 (Image: RIKEN)

Synthesis and beginning of the decay chain for element 113 (Image: RIKEN)

The first synthetic element was created in 1940, and so far 20 different elements have been made. All of these are unstable and last only seconds, at most, before breaking apart into smaller elements.
To synthesize element 113, Morita and his team collided zinc nuclei (with 30 protons each) into a thin layer of bismuth (which contains 83 protons). When 113 was created, it quickly decayed by shedding alpha particles, which consist of two protons and two neutrons each. This process happened six times, turning element 113 into element 111, then 109, 107, 105, 103 and finally, element 101, Mendelevium (also a synthetic element).
Morita's group seemed to create element 113 in experiments conducted in 2004 and 2005, but the complete decay chain was not observed, so the discovery couldn't be confirmed. Now that this specific pattern resulting in Mendelevium has been seen, the scientists say it "provides unambiguous proof that element 113 is the origin of the chain."

Limit to how large atom can be:
Scientists have long wondered whether there is a limit to the number of protons and neutrons that can be clustered together to form the nucleus of an atom. A new study comes closer than ever to finding the answer by estimating the total number of nucleus variations that can exist.
The periodic table of elements includes 118 known species of atoms, and each of these exists (either naturally or synthetically) in several versions with differing numbers of neutrons, giving rise to a total of about 3,000 different atomic nuclei. As technology has improved over the years, physicists have been building heavier and heavier atoms — element 117 was created only last year, and researchers are hot on the trail of 119. New projects are in the works to add and subtract neutrons to known elements to create ever more exotic variations, known as isotopes. 
 In an issue of the journal Nature, researchers report that roughly 6,900 nuclides (variations of atomic nuclei), plus or minus 500, should be possible.

"Beyond the 7,000, we are talking about nuclides whose lifetimes can be so short that they can't form," said research team member Witold Nazarewicz of the University of Tennessee, the Oak Ridge National Laboratory in Tennessee and Warsaw University in Poland. "The system would decay instantly."
Even within those 7,000, the vast majority would be unstable, lasting only a tiny fraction of a second.  Of the 3,000 known nuclides, only 288 are stable.
Atoms are limited in the number of protons they can contain, because each proton is positively charged, and because "like repels like," they want to push each other away. Even neutrons, which have no charge, are slightly repulsive to each other. A mysterious force called the strong interaction, which is about 100 times stronger than electromagnetism, is what binds protons and neutrons together in nuclei.
"The nature or the exact form of the strong force, especially in heavier nuclei, is still a subject of very intense experimental and theoretical research," Nazarewicz told LiveScience.

Tuesday, December 4, 2012

Lost languages in Indian perspective

The enigma of the world's undeciphered scripts, may be it's tantalizing possibility of giving new voice to long-hushed peoples and civilizations.
'cave inscription'  found in  India>Chhattisgarh>Surguja>Ambikapur>Ramgarh
Perhaps it's the puzzle solver's delight in the mental challenges posed by breaking their codes.
Whatever the reasons, the public has long been fascinated with undeciphered ancient scripts !!

The Language of the Gods in the World of Men
Sheldon Polloc

Sheldon I. Pollock is a scholar of Sanskrit, Indian intellectual and literary history, and comparative intellectual history. He is currently the Arvind Raghunathan Professor of South Asian Studies at the Department of Middle Eastern, South Asian, and African Studies at Columbia University. He was general editor of the Clay Sanskrit Library and is founding editor of the Murty Classical Library of India. Pollock has received the Andrew W. Mellon Distinguished Achievement Award and the Government of India's Padma Sri.

'cave painting'  found in  India>Chhattisgarh>Surguja>Ambikapur>Ramgarh

  In this work of impressive scholarship, Sheldon Pollock explores the remarkable rise and fall of  Sanskrit, India's ancient language, as a vehicle of poetry and polity. The corpus of Sanskrit literature encompasses a rich tradition of poetry and drama as well as scientific, technical, philosophical and dharma texts.   He traces the two great moments of its transformation: the first around the beginning of the Common Era, when Sanskrit, long a sacred language, was reinvented as a code for literary and political expression, the start of an amazing career that saw Sanskrit literary culture spread from Afghanistan to Java. The second moment occurred around the beginning of the second millennium, when local speech forms challenged and eventually replaced Sanskrit in both the literary and political arenas. Drawing striking parallels, chronologically as well as structurally, with the rise of  Latin literature and the Roman empire, and with the new vernacular literatures and nation-states of late-medieval Europe, The Language of the Gods in the World of Men asks whether these very different histories challenge current theories of culture and power and suggest new possibilities for practice.

Crisis in the classics 

Ananya Vajpeyi teaches South Asian History at the University of Massachusetts. She was educated at the Jawaharlal Nehru University, Oxford University, where she read as a Rhodes Scholar, and the University of Chicago. 

It is stunning that in a country with dozens of Sanskrit departments at all major state-level and national universities, a number of Sanskrit colleges dating from the colonial period, an entire network of matha, pathshala, and vidyapeeth institutions comprising a parallel educational economy (especially in southern India), compulsory Sanskrit at the middle school level for millions of school children (which implies thousands of school teachers), and innumerable texts stored in homes, libraries, archives, and temples, we do not have the most basic infrastructure to read, preserve, or create knowledge in or about Sanskrit. Neither the inertia from a prior era, nor new initiatives have kept Sanskrit going.

Study needs to be undertaken for not just Sanskrit, but also a number of other classical languages, such as  Malayalam, Kannada Bengali, Tamil Persian, and Brajbhasha ( Brij)

 No Future without the past

Try to imagine independent India without its founding, fundamental, and inalienable texts, whether ancient or modern, upper  caste or  outcaste, the sermons of the Buddha, the edicts of  Aśoka, the epics of Ved Vyasa's (Mahabharata) and  Valmiki (Ramayana), the songs of its Sufis and bhakti poets ( Kabir and Tulsidas), the teachings of its saints and sages, the lessons of its gurus, the Indian Constitution of Republic of India , Mahatma Gandhi’s letters,  Dr B.R. Ambedkar’s articles, Jawaharlal Nehru’s speeches,  Rabindranath Tagore’s national anthem (Jana Gana Mana), and the innumerable stories that we continuously recount. Not land, blood, race, religion, or state – language itself is our essence. Without our words, we are nothing. 

Arguably, linguistic diversity and literary richness ought to be India’s strongest suit, given its history both as an old civilization and as a diverse and multi-vocal democracy. Alas, we have driven our languages and literatures into the ground. Linguistic chauvinism and language-centred identity politics abound. Yet, not a single political ideology protects and nurtures the languages, which remain orphans in the political process and in the networks of institutional patronage cultivated by different parties. 

It may seem perverse to worry about Sanskrit – a so-called “ dead” language – when Indians are becoming less and less fluent in the living regional languages, most of which have numerically more or as many speakers as major European and Asian languages. It may seem that with the downfall of Brahmin and upper-caste hegemony in the social, political, and cultural spheres, it was only natural for the language constitutively linked to savarna power for centuries to go into terminal decline. 

The future gloom
As usual in India, the root of the matter lies not in a shortage of money, but in the lack of a vision. Politically motivated interest, fitful as it has been, has only worsened the situation, ruining even the few centres of excellence that had survived on the intellectual steam and personal integrity of their staff until the early 1990s – University of Pune, the Deccan College Post-Graduate and Research Institute, and the Banaras Hindu University come immediately to mind.
The inscriptions found in the eastern part of India were written in the Magadhi language, using the Brahmi script. In the western part of India, the language used is closer to Sanskrit, using the Kharoshthi script, one extract of Edict 13 in the Greek language, and one bilingual edict written in Greek and Aramaic. These edicts were deciphered by British archeologist and historian James Prinsep in 1837.

James Prinsep in medal cast circa 1840. National Portrait Gallery (London)
 If the Indian education and learning continued in the present set of mood and mode then very soon the number of people capable of reading and understanding the old scriptures ( sacred languages)  shall come to naught. India is going to be the only cultural center whose literary heritage including the history shall rest in the hands of scholars from foreign countries.
  We must be connected live with our rich linguistic past. Our mythological subjects portray universal approach and paint eternal truth about humanity !!

*author Sheldon and Ananya's pictures and views shared thankfully.

 

 

 

Tuesday, November 27, 2012

Radioactive element poisoning

Radioactive elements:A radioactive element is one with an unstable nucleus, which radiates alpha, beta or gamma radiation and gets converted to a stable element.
An element will undergo decay if:

  1. It has more than 83 protons.
  2. The ratio of protons to neutrons is very close. For example, Carbon, having 6 protons and 6 neutrons (therefore having a 1:1 ratio of protons and neutrons) is a very stable atom. On the other hand, Bismuth, an unstable atom, has 126 neutrons and 83 protons, giving it a 1.52:1 ratio.
  3. Nuclides containing certain numbers of protons or neutrons (2, 8, 20, 50, 82, and 126) are more stable than others.
  4. Nuclides with even numbers of both protons and neutrons and more stable than those with odd numbers of
Radioactivity:It's a spontaneous and random phenomenon whereby nuclei of certain chemical elements like Uranium, radiate gamma rays (high frequency electromagnetic radiation), beta particles (electrons or positrons) and alpha particles (Helium Nuclei).


Key factor lies in the nucleus of an element:To understand radioactivity, we need to explore the structure of an atomic nucleus. Every nucleus contains neutrons as well as protons. Neutrons are neither positively charged, nor negatively charged, they are neutral particles. Protons are positively charged. And as we know that like charges repel each other while unlike charges attract each other. In the nucleus, protons and neutrons are cramped together in a really very small space.
The protons in the nucleus, all being positively charged, repel each other! So if all the protons repel each other, how does the nucleus stay glued together and remain stable? It is because of the 'Nuclear Force'.

This force is more stronger than the electromagnetic force, but the range of this force is only limited to size of the nucleus, unlike electromagnetic force whose range is infinite. This nuclear force acts between the protons and neutrons, irrespective of the charge and it's always strongly attractive. However, it has limitations of range. So, in the nucleus, there is a constant tussle between the repelling electromagnetic coulomb force of protons and the attractive strong nuclear force.

In a nucleus like Uranium, which has almost 92 protons, coulomb repulsive force becomes too much for the nuclear force to contain. Subsequently, the nucleus is very unstable and radioactive decay occurs and Uranium decays into a more stable element. Such an unstable nucleus like Uranium, when gently tapped by a neutron, splits up into two other nuclei through nuclear fission, releasing tremendous amount of energy in the process! This is the principle on which nuclear energy and nuclear weapons are based.

A full explanation of radioactivity can only be given, if we plunge deep into quantum physics and elementary particle physics.

Types of Radioactive Decay:This decay may occur in any of the following three ways:


alpha decay, in which a nucleus emits an alpha particle, which consists of 2 neutrons and 2 protons and is equivalent to a helium nucleus; beta-minus decay, in which an electron is emitted along with an antineutrino (not shown); gamma decay, in which a nucleus gets rid of its excess energy by emitting a gamma ray photon; and proton decay, the release of a single proton from a nucleus. Proton decay is shown from a normal spherically shaped nucleus and from a deformed, football- shaped nucleus. Researchers have found that the rates of proton radioactivity are different for the two types of nuclei because of their different shapes.
Alpha Decay: Nucleus emits a helium nucleus (called an Alpha Particle) and gets converted to another nucleus with atomic number lesser by 2 and atomic weight lesser by 4.
 
Beta Decay: Beta decay could be of two types; either through emission of an electron or positron (the antiparticle of electron). Electron emission causes an increase in the atomic number by 1, while positron emission causes a decrease in the atomic number by 1. In some cases, double beta decay may occur, involving the emission of two beta particles.
 
Gamma Decay: Gamma decay just changes the energy level of the nucleus.
 
Electron Capture: One of the rarest decay modes is electron capture. In this phenomenon, an electron is captured or absorbed by a proton rich nucleus. This leads to the conversion of a proton into a neutron in the nucleus, along with release of an electron neutrino. This leads to a decrease in atomic number (transmuting the element in the process), while leaving the atomic mass number unchanged.

A radioactive element may have more than one decay mode.


Polonium:
Polonium is a chemical element with the symbol Po and atomic number 84, discovered in 1898 by Marie and Pierre Curie. 
Symbol: Po
Electron configuration: [Xe] 6s2 4f14 5d10 6p4
 Atomic radius: 190 pm
Atomic number: 84
Discovered: 1898
Atomic mass: 209 u
Polonium poisoning:The maximum safe body burden of Po-210 is only seven picograms. A microgram of Po-210, which is no larger than a speck of dust, would certainly deliver a fatal dose of radiation.  
Polonium is only slowly excreted - it has a biological half life of around a month - and this ensures its alpha particles continue to wreak havoc once inside the body. One likely method of administration would be as a soluble salt (citrate or nitrate, for example) added to the victim's food or drink.Once ingested, polonium is rapidly distributed around the body, leaving a trail of reactive radicals in its wake as it steals electrons from any molecule it encounters. Low-level DNA damage from radiation can cause genetic changes that affect cell replication, whereas more severe damage may force the cell to self destruct by apoptosis.

The alleged mysteries:
The body of the former Palestinian leader Yasser Arafat is being exhumed on Tuesday today to test to see if he was the victim of Polonium-210 poisoning. The tests will attempt to establish the cause of his death in Paris in 2004.
Polonium was first discovered by Marie and Pierre Curie in 1898. It is a radioactive element that occurs naturally in the earth's crust.
According to scientists from the University of Chicago Polonium-210 is traditionally used to clear dust from camera lenses or photographic film.
It is poisonous if ingested and it's believe that the Russian dissident Alexander Litvinenko who died in November 2006 was the victim of Polonium-210 poisoning.
 *Note: all pictures thankfully shared from various sources..

Monday, November 26, 2012

Gregor Johann Mendel: Father of Genetics

Scientists Decode Black Dahlias:Vienna, Nov 25, 2012: Scientists have now decoded why some dahlias are black, a rarity, after analyzing as to why the plant displays varying hues, from white to yellow to red to purple.

Dahlia variabilis hort. is a popular garden flower. Continuous dahlia breeding worldwide has led to a huge number of cultivars many of them showing red hues, but black hues of dahlia flowers occur rarely. Credit: Dr. Heidi Halbwirth
To examine the biochemical basis for the distinctive dark coloring of the black dahlia, the research team from the Vienna University of Technology in Austria used pigment, enzyme and gene expression analyses. They determined that the majority of black cultivars have very low concentrations of flavones, as confirmed by low FNS II expression. Since flavones compete with anthocyanin biosynthesis for common intermediates, the lack of flavones favors the accumulation of huge amounts of anthocyanins that are found in black dahlias. The flavonol contents of black dahlias increased slightly parallel to the decrease of flavones. (Citation: Jana Thill, Silvija Miosic, Romel Ahmed, Karin Schlangen, Gerlinde Muster, Karl Stich and Heidi Halbwirth, ''Le Rouge et le Noir': A decline in flavone formation correlates with the rare color of black dahlia (Dahlia variabilis hort.) flowers', BMC Plant Biology 2012, 12:225) 
 *
Every research paper in Genetics 
reminds us a genius of all time
** 
The monk in the garden
Gregor Johann Mendel
The Father of Genetics
***


AKA Gregor Johann Mendel
Born: 22-Jul-1822Birthplace: Hynice, CzechiaDied: 6-Jan-1884Location of death: Brno, CzechiaCause of death: unspecifiedRemains: Buried, Central Cemetery, Brno, Czechia
Gender: MaleReligion: Roman CatholicRace or Ethnicity: WhiteOccupation: Scientist, Botanist, Religion
Nationality: CzechiaExecutive summary: Discovered the laws of inheritance

Father: Anton (farmer)Mother: RosineSister: VeronicaSister: Theresia
    High School: Troppau Gymnasium, Opava, Czechia (1840)
    University: Olmutz Philosophical Institute (1840-43)
    Theological: Brünn Theological College, Brno, Czechia (1847)
    Teacher: Znojmo Gymnasium, Znojmo, Czechia (1849-51)
    Teacher: Mathematics and Biology, University of Vienna (1851-54)
    Administrator: Abbot and Prelate, St Thomas's Abbey, Brno, Czechia (1854-68)
    Ordained by the Roman Catholic Church 6-Aug-1847
    Asteroid Namesake 3313 Mendel
    Lunar Crater Mendel (48.8° S, 109.4° W, 138 km. diameter)
    Martian Crater Mendel (58.8° S, 161° E, 79 km. diameter)

The Lost and Found Genius of Gregor Mendel: Most people know that Gregor Mendel, the Moravian monk who patiently grew his peas in a monastery garden, shaped our understanding of inheritance. But people might not know that Mendel's work was ignored in his own lifetime, even though it contained answers to the most pressing questions raised by Charles Darwin's revolutionary book, ON ORIGIN OF THE SPECIES, published only a few years earlier. Mendel's single chance of recognition failed utterly, and he died a lonely and disappointed man (Before his death in 1884 he wrote, "I am convinced that it will not be long before the whole world acknowledges the results of my work,"). Thirty-five years later, his work was rescued from obscurity in a single season, the spring of 1900, when three scientists from three different countries nearly simultaneously dusted off Mendel's groundbreaking paper and finally recognized its profound significance. The perplexing silence that greeted Mendel's discovery and his ultimate canonization as the father of genetics make up a tale of intrigue, jealousy, and a healthy dose of bad timing. 
In 1857, Austrian monk Gregor Mendel decided to breed pea plants in the large monastery garden of Brunn. He loved botany (studying plants) and he had very much wanted to become a high school teacher. Unfortunately, he had failed the teaching exam three times, so he had to be content with living as a monk. It took him eight years and 30,000 pea plants to discover these natural laws of heredity (now known as the Mendelian Laws). Afterwards, Mendel wished to publish his findings, but feared that no one would listen to him because he was only a monk and not even qualified to teach high school! Nevertheless, he sent his reports to the most famous botanist in Europe, Karl Wilhelm von Nageli of Switzerland, hoping to gain his sponsorship (support of his work). von Nageli ignored Mendel's work, though, and sent it back to him. Mendel was able to get his paper published in a scientific journal several years later, but - just as he had feared - no one acknowledged it because he was an unsponsored amateur. Saddened, he gave up botany and devoted his days to monastic life. Mendel died in 1884. It was nearly forty years later when his writings and research were rediscovered and found to be true.

On New Year's Eve, 1866, Gregor Mendel wrote to the prominent Swiss botanist Carl Nägeli to tell him about his now classic experiments with Pisum peas. In the margins of the letter, Nägeli scribbled a note: "only empirical and not rational."

MENDEL, Gregor (1822-84)
Mendel was born on July 22, 1822 in Heizendorf, Austria, (now known as Hyncice in Czechoslovakia). He was born Johann Mendel into a poor farming family. At that time it was difficult for poor families to obtain a good education and the young Mendel saw the only way to escape a life of poverty was to enter the monastery at Brunn in Moravis, (now Brno in Czechoslovakia). Here he was given the name Gregor. This monastery was the Augustinian Order of St Thomas, a teaching order with a reputation as a centre of learning and scientific enquiry.

He took the name Gregor when he entered the monastery in Brunn, Moravia (now Brno, Czech Republic) in 1843. He studied for two years at the Philosophical Institute in Olmutz (now Olomouc, Czech Republic), before going to Brunn. He became a priest in 1847. For most of the next 20 years he taught at a nearby high school, except for two years of study at the University of Vienna (1851-53). In 1868 Mendel was elected abbot of the monastery.

To enable him to further his education, the abbot arranged for Mendel to attend the University of Vienna to get a teaching diploma. However, Mendel did not perform well. He was nervous and the University did not consider him a clever student. Mendel's examiner failed him with the comments, " he lacks insight and the requisite clarity of knowledge". This must have been devastating to the young Mendel. who in 1853 had to return to the monastery as a failure.

Mendel's famous garden-pea experiments began in 1856 in the monastery garden. He proposed that the existence of characteristics such as blossom color is due to the occurrence of paired elementary units of heredity, now known as genes. Mendel presented his work to the local Natural Science Society in 1865 in a paper entitled "Experiments with Plant Hybrids." (Gregor Mendel 1865.Versuche uber Pflanzen-Hybriden. Verh. Naturfosch. Ver. Brunn, Vol 4:3-47.) Administrative duties after 1868 kept him too busy for further research. He lived out his life in relative obscurity, dying on Jan. 6, 1884. In 1900, independent research by other scientists confirmed Mendel's results.
Mendel's garden plot at the Augustine monastery in Brno, Czech Republic.
He published his results in the Journal of the Brno Natural History Society in 1866, writing:
"It is now clear that the hybrids form seeds having one or other of two differentiating characters, and of these one half develop again the hybrid form, while the other half yield plants which remain constant and receive the dominant or the recessive characters in equal numbers."




Mendel's field notes
While Mendel's research was with plants, the basic underlying principles of heredity that he discovered also apply to people and other animals because the mechanisms of heredity are essentially the same for all complex life forms.

Through the selective cross-breeding of common pea plants (Pisum sativum) over many generations, Mendel discovered that certain traits show up in offspring without any blending of parent characteristics.  For instance, the pea flowers are either purple or white--intermediate colors do not appear in the offspring of cross-pollinated pea plants.  Mendel observed seven traits that are easily recognized and apparently only occur in one of two forms:
1.    flower color is purple or white 5.    seed color is yellow or green
2. flower position is axil or terminal        6. pod shape is inflated or constricted
3. stem length is long or short 7. pod color is yellow or green
4. seed shape is round or wrinkled


Experiments on plant hybridization:
In cross-pollinating plants that either produce yellow or green pea seeds exclusively, Mendel found that the first offspring generation (f1) always has yellow seeds.   However, the following generation (f2) consistently has a 3:1 ratio of yellow to green

 diagram showing the result of cross-pollination in the first 2 offspring generations--in generation f1 all are yellow peas but in generation f2 the ratio of yellow to green peas is 3 to 1
This 3:1 ratio occurs in later generations as well.   Mendel realized that this was the key to understanding the basic mechanisms of inheritance.
diagram showing the result of cross-pollination in the 3rd offspring generation--the offspring of the 2nd generation green peas are all green, the offspring of one third of the 2nd generation yellow peas are all yellow, the offspring of the other 2nd generation yellow peas are green or yellow in a 3 to 1 ratio
He came to three important conclusions from these experimental results:
1.   that the inheritance of each trait is determined by "units" or "factors" that are passed on to descendents unchanged      (these units are now called genes)
2. that an individual inherits one such unit from each parent for each trait
3. that a trait may not show up in an individual but can still be passed on to the next generation.
It is important to realize that, in this experiment, the starting parent plants were homozygous for pea seed color.  That is to say, they each had two identical forms (or alleles) of the gene for this trait--2 yellows or 2 greens.  The plants in the f1 generation were all heterozygous.   In other words, they each had inherited two different alleles--one from each parent plant.  It becomes clearer when we look at the actual genetic makeup, or genotype , of the pea plants instead of only the phenotype, or observable physical characteristics.
diagram of genotypes of pea plants in 3 generations after cross-pollination
Note that each of the f1 generation plants (shown above) inherited a Y allele from one parent and a G allele from the other.  When the f1 plants breed, each has an equal chance of passing on either Y or G alleles to each offspring.
With all of the seven pea plant traits that Mendel examined, one form appeared dominant over the other, which is to say it masked the presence of the other allele.  For example, when the genotype for pea seed color is YG (heterozygous), the phenotype is yellow.  However, the dominant yellow allele does not alter the recessive green one in any way.   Both alleles can be passed on to the next generation unchanged.
Mendel's observations from these experiments can be summarized in two principles:
1.   the principle of segregation
2. the principle of independent assortment


According to the principle of segregation, for any particular trait, the pair of alleles of each parent separate and only one allele passes from each parent on to an offspring.  Which allele in a parent's pair of alleles is inherited is a matter of chance.  We now know that this segregation of alleles occurs during the process of sex cell formation (i.e.meiosis).

illustration of the segregation of alleles in the production of sex cells

Segregation of alleles in the production of sex cells
According to the principle of independent assortment, different pairs of alleles are passed to offspring independently of each other.  The result is that new combinations of genes present in neither parent are possible.  For example, a pea plant's inheritance of the ability to produce purple flowers instead of white ones does not make it more likely that it will also inherit the ability to produce yellow pea seeds in contrast to green ones.  Likewise, the principle of independent assortment explains why the human inheritance of a particular eye color does not increase or decrease the likelihood of having 6 fingers on each hand.  Today, we know this is due to the fact that the genes for independently assorted traits are located on different chromosomes 
These two principles of inheritance, along with the understanding of unit inheritance and dominance, were the beginnings of our modern science of genetics.

Gregor Mendel's genius spelt out in a pea-flavoured Google doodle. Born into poverty on a farm in Austria, Gregor Mendel and his peas went on to sow the seeds of modern genetics

*Note: all pictures thankfully shared from various sources.



















 








































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