منتدى الشعوب
عزيزي الزائر / عزيزتي الزائرة يرجي التكرم بتسجبل الدخول اذا كنت عضو معنا
او التسجيل ان لم تكن عضو وترغب في الانضمام الي اسرة المنتدى
سنتشرف بتسجيلك
شكرا
ادارة المنتدى

شاطر
اذهب الى الأسفل
avatar
فيصل
المدير
المدير
عدد المساهمات : 4488
تاريخ التسجيل : 06/08/2010
العمر : 34
الموقع : http://choob.yoo7.com
http://choob.yoo7.com

-1- Gregor Mendel

في الأربعاء يوليو 20, 2011 8:11 pm




  • Advertisements


































Try a FREE 30 day preview of Daily News Briefing













  • Search
















  • World
  • USA
  • Commentary
  • Business
  • Environment
  • Innovation
  • Science
  • The Culture
  • Books

















  • Innovation
  • Tech
  • Pioneers
  • Responsible Tech
  • Tech Culture
  • Blog: Horizons
  • Latest News Wires
















FREE daily e-mail

































































































Why you should care about Gregor Mendel





Today's Google Doodle reminds us that without the meticulous work of Gregor Mendel, evolutionary biology would make no sense.






























Widely
regarded as the father of modern genetics, Moravian friar Gregor Mendel
was the first to discover that inherited traits do not blend, but
remain intact through generations. Google honored Gregor Mendel today
with a special "doodle."

akg-images/Newscom



Enlarge






















0 and 0













By




Eoin O'Carroll, CSMonitor.com /
July 20, 2011













Google's logo today commemorates the 189th birthday of Gregor Mendel, the Moravian monk who is widely regarded as the Father of Genetics.

Skip to next paragraph



































  • Gallery: Google's doodles















Related stories





  • Teaching creationism: Louisiana law that skirts US ban survives challenge



  • 'Going Rogue': Is Sarah Palin a creationist?



  • How to grow and serve sugar snap peas



Topics



  • History of Science
  • Cultural History
  • History
  • Culture and Lifestyle
  • Life Sciences
  • Evolution
  • Sciences













You might remember from high school biology class that Mendel
mucked about with peas, and that he came up with the concept of dominant
and recessive traits. But why, exactly, is any of this important in
2011?Because without Mendel's contributions, Charles Darwin's
theory of evolution would make no sense. In his 1859 book "The Origin
of Species," Darwin postulated that species evolve by means of mutation
and natural selection. For example, an antelope-like creature with a
slightly longer neck will be able to dine on leaves that are unreachable
by her peers. This advantage will make her more likely to survive into
adulthood and to have more offspring, who are themselves more likely to
have inherited their mother's longer neck. Eventually, over thousands of
generations, the trait for longer necks spreads through the population,
and they gradually become giraffes.
RELATED: Did you see all 16 of Roger Hargreaves' Google doodles?
So
far, so good. But in Darwin's time, nobody understood how traits were
inherited. The dominant belief back then was that inherited traits
blended together. Under this model, the daughter of a long-necked mother
and a normal-necked father will be only somewhat longish necked. And
when that somewhat-longish-necked daughter mates with a normal-necked
male, their offspring will be only a little bit long-necked, and so on
through the generations until the trait is diluted away.As the great Scottish polymath Fleeming Jenkins argued in his 1867 takedown of Darwin's theory,
"We have abnormal variations called sports, which may be supposed to
introduce new organs or habits in rare individuals. This case must be
again subdivided; we may suppose the offspring of the sports to be
intermediate between their ancestor and the original tribe. In this case
the sport will be swamped by numbers, and after a few generations its
peculiarity will be obliterated."As Darwin struggled to reconcile his observations with the theory of blending inheritance, some 800 miles away in Brno (part of what is now the Czech Republic),
Mendel was working on a solution. Trained in physics, the Augustinian
monk brought his considerable skills in statistical analysis to bear on
his cultivation of 29,000 pea plants, which he grew in an experimental
garden on the grounds of his monastery. Mendel noticed that the
plants' traits did not blend together: a pea plant with yellow pods
cross-pollinated with one with green pods plant did not result in
yellowish-green pods, as would have been expected. Instead, every single
pea in the first generation crop remained yellow. But then when Mendel
self-pollinated that crop, some plants in the the second generation went
back to being green, while most of them remained yellow, always in a
3:1 ratio. Mendel realized that inherited traits remained intact through
generations, carried by what he called "factors." (Mendel never used
the word "gene," which wasn't coined until 1913.)Mendel's library
of 20,000 books included a copy of Darwin's "Origin," but Mendel never
seemed to connect his discoveries with the theory of evolution. For
his part, Darwin himself came tantalizingly close to repeating Mendel's
discoveries. In 1866, the same year that Mendel published his theory of
particulate inheritance, Darwin was experimenting on his own – with pea
plants no less.This 2003 Guardian article by British biologist Richard Dawkins quotes a letter, discovered by chance in the British Library, from Darwin to his colleague Alfred Wallace,
in which Darwin writes, "I crossed the Painted Lady and Purple
sweetpeas, which are very differently coloured varieties, and got, even
out of the same pod, both varieties perfect but none intermediate."But
Darwin didn't take this discovery much further, even though his 1876
book, "The Effects of Cross and Self Fertilisation in the Vegetable
Kingdom," covered much of the same ground that Mendel had covered.Mendel died in 1884, and just sixteen years later his work was rediscovered independently by scientists Hugo de Vries and Carl Correns.
It wasn't until the 1930s and 40s, however, that biologists connected
Mendel's observations to Darwin's theory, creating the so-called Modern
Synthesis that is the currently accepted model in evolutionary biology.
RELATED: How to keep playing Google Doodle Pac-Man for free










Related stories






  • Teaching creationism: Louisiana law that skirts US ban survives challenge



  • 'Going Rogue': Is Sarah Palin a creationist?



  • How to grow and serve sugar snap peas






Topics




  • History of Science
  • Cultural History
  • History
  • Culture and Lifestyle
  • Life Sciences
  • Evolution
  • Sciences
  • Biology
























































Try the new weekly Monitor at a price so low... it's like getting 18 issues FREE!







Read Comments





View reader comments | Comment on this story














  • World »














    Uganda's booming grasshopper industry leaps over tradition





  • World »














    Africa's summer of strikes







  • USA »

















    'Harry Potter' breaks records: three trends behind the success






  • Making a Difference
















    Naomi Oreskes: fierce defender of climate change science – and scientists




  • The Culture »














    Salvation Boulevard: movie review





  • The Culture »














    Harry Potter and the Deathly Hallows: Part 2: movie review







  • Opinion »

















    Opinion:
    Four reasons American media should lowercase 'Internet'





  • The Culture »














    China's Great Wall: A beautiful barrier





  • The Culture »














    In America's Deep South, a front seat for Freedom Riders





  • Business »














    Today's consignment shop: hip and online





  • The Culture »














    In China, a baby breaks the language barrier





  • The Culture »














    Ham radio hangs on


























More Innovation



















  • Horizons
    Spotify: Good for music lovers, bad for musicians?
















  • Apple storms ahead with new MacBook Air, record sales















  • Horizons
    Google+ iPhone app goes live

















  • Horizons
    Anonymous apparently target of sweeping FBI crackdown

















  • Horizons
    Droid Bionic gets sign-up screen, but no release date

















  • Horizons
    Americans want iPhone, buy Android
















  • Phone hacking rocks Scotland Yard, News Corp. – and Cameron?















  • Horizons
    New MacBook Air with OS X Lion roars in the distance, but many questions remain

















  • Horizons
    Google stock soars on good news from Mountain View
















  • Amazon tablets mix best of Kindle and iPad: report































About these ads




















Most viewed







  1. 'Gang of Six' plan hailed as debt-ceiling breakthrough. What's in it?



  2. Wendi Deng saves Rupert Murdoch from foam pie (VIDEO)



  3. UN declares famine in Somalia: How to help



  4. Gold prices plummet on debt talk



  5. Gallup chief puzzled by Obama's poll numbers























Photos of the day


07.19.11 »
























CSMonitor.com on Facebook




























In Pictures






















Space photos of the day: Comets














Inside CSMonitor.com:

















  • Six GOP candidates to hold Twitter debate. Here's how to see it.



    Wednesday's Twitter debate among six GOP presidential candidates is a
    first. Will the 140-character format produce a series of sound bites? Or
    will interactivity make it more meaningful for voters?

  • Backchannels:


    Is Afghanistan safer, or isn't it?


  • Vox News:


    Murdoch scandal: How are his big US media outlets covering it?


  • Backchannels:


    So who are Libya's rebels exactly?



  • Gallup chief puzzled by Obama's poll numbers




























About these ads














FREE daily e-mail newsletter









CSMonitor.com top stories, cartoons and photos


























See sample | Privacy Policy


















What happens when ordinary people decide to pay it forward? Extraordinary change. See how individuals are making a difference...






Naomi
Oreskes, a historian who studies scientific findings and funding, was
drawn into the emotional debate around global warming after she publicly
stated that climate change is a settled scientific fact.





Naomi Oreskes: fierce defender of climate change science – and scientists

Naomi
Oreskes has become a leading voice in defense of the science underlying
global warming and the scientists who are researching it.















Become part of the Monitor community


32K on Facebook | 11K on Twitter | 2,180 on YouTube































































Sponsored Links






  • Booking Agency


    • Grabow Entertainment Agency

    </li>




  • Computers


    • PowerEdge Memory

    </li>




  • Fitness


    • Endless Pools Swimming Machines

    </li>











  • Legal Services


    • Whistleblower

    </li>




  • Real Estate


    • International Shipping

    • Mortgage Calculator

    • Moving

    • Moving Companies

    • Real Estate

    </li>








  • Speakers Bureau


    • Christian Speakers

    • Celebrity Speakers Bureau

    • Motivational Speakers Bureau

    • Sports Speakers Bureaus

    </li>




  • Web Services


    • Dedicated Servers

    • Hosting

    </li>





































About these ads





  • Home
  • About
  • Content Map
  • Monitor Topics
  • Contact Us
  • Subscribe
  • E-Readers
  • Text
  • Specials
  • Multimedia
  • Make Us Your Home Page



  • Careers
  • Corrections
  • Find us online
  • Advertise With Us
  • Monitor Mall
  • Today's Article on Christian Science

_________________
ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ
ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ



قالوا
اسكت وقد خوصمت قلت له مإن الجـواب لبـاب الشـر مفتـاح

والصمت عن
جاهلٍ أو أحمقٍ شرف وفيه أيضاً لصون العرض إصـلاح

أما ترى الأسد
تخشى وهي صامته ؟والكلب يخسى لعمري وهـو نبـاح[/size]
avatar
تاج الياسمين
المشرف العام
المشرف العام
عدد المساهمات : 8574
تاريخ التسجيل : 16/08/2010
الموقع : http://choob.yoo7.com

-1- رد: Gregor Mendel

في الأربعاء يوليو 20, 2011 9:42 pm
رغم اني لم افهم
لكن مشكوور على هذا المجهود
تحيااتي

_________________













avatar
ياسمين 2
نائب المدير الاول
نائب المدير الاول
عدد المساهمات : 1672
تاريخ التسجيل : 01/05/2011

-1- رد: Gregor Mendel

في الجمعة يوليو 29, 2011 11:17 pm
un grand homme qui a laissé ses empreintes , lesquelles empreintes ayant marqué l'histoire africaine et qui demeureront à jamais éternelles.
avatar
sad smile
المراقب العام
المراقب العام
عدد المساهمات : 4405
تاريخ التسجيل : 13/01/2011
الموقع : في دار بابا

-1- رد: Gregor Mendel

في الخميس أغسطس 04, 2011 1:35 pm
شكرا على الموضوع
الرجوع الى أعلى الصفحة
صلاحيات هذا المنتدى:
لاتستطيع الرد على المواضيع في هذا المنتدى