Evolutionary Foundations: -Biological Evolution Began More Than Three and a Half Billion Years Ago

Earth was formed about 4.5 billion years ago, and the first evidence of life dates to more than 3.5 billion years ago. In 1996, scientists working in Greenland found not fossil remains but chemical evidence of life from as far back as 3.85 billion years ago, forms of carbon embedded in rock that appear to have a distinctly bio logical origin. Somewhere on Earth during its first billion years there arose the first simple organism, capable of replicating its own structure from a template (RNA?) that was the first genetic material. Because the terrestrial atmosphere at the dawn of life was nearly devoid of oxygen, and because there were few microorganisms to scavenge organic compounds formed by natural processes, these compounds were relatively stable. Given this stability and eons of time, the improbable became inevitable: the organic com pounds were incorporated into evolving cells to produce increasingly effective self-reproducing catalysts. The process of biological evolution had begun.

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قسم المعارف يواصل دعم الحركة الثقافية بإصدارات متنوِّعة عَبرَ معرض الكتاب الدائم

إقبال نسوي واسع على منافذ التبرع في العتبة العباسية المقدسة لدعم الشعبين الإيراني واللبناني

العتبة العباسية المقدسة تباشر تنفيذ المرحلة الثالثة من أعمال التوسعة

بمحافظة ذي قار.. قسم الشؤون الفكرية يقيم ندوة معرفية عن دور بصيرة العلماء في سلامة المجتمع

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سرّ بسيط لصحة القلب.. أطعمة تخفض الكوليسترول خلال أسابيع

سبب خفي لإعتام عدسة العين ؟

عوامل خفية تسرّع شيخوخة الدماغ

أسباب الرغبة الشديدة في تناول الحلويات والأطعمة النشوية

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كندا تصنع كاسحة جليد من جيل جديد

رواد "أرتيميس 2" يكشفون تفاصيل حياتهم في الفضاء

حفريات صينية تكشف كائنات بحرية عاشت قبل 546 مليون عام

روسيا تطلق صاروخ "سويوز-2.1 إيه" من قاعدة بليسيتسك الفضائية

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مواضيع ذات صلة

Evolutionary Foundations: -Eukaryotic Cells Evolved from Prokaryotes in Several Stages

Evolutionary Foundations: -The First Cell Was Probably a Chemoheterotroph

Evolutionary Foundations: -RNA or Related Precursors May Have Been the First Genes and Catalysts

Evolutionary Foundations:- Biomolecules First Arose by Chemical Evolution

Evolutionary Foundations: - Changes in the Hereditary Instructions Allow Evolution

Genetic Foundations-: The Structure of DNA Allows for Its Replication and Repair with Near-Perfect Fidelity

Genetic Foundations-: Genetic Continuity Is Vested in Single DNA Molecules

Genetic Foundations

Physical Foundations-: Metabolism Is Regulated to Achieve Balance and Economy

Physical Foundations-: Enzymes Promote Sequences of Chemical Reactions

Physical Foundations:- Keq and ΔG Are Measures of a Reaction’s Tendency to Proceed Spontaneously

Physical Foundations:- Energy Coupling Links Reactions in Biology