2Q-EASL INTRODUCTION TO LIFE SCIENCE.pptx
- 1. INTRODUCTIO N TO LIFE SCIENCE ENGR. RENE N. RAMILO Earth and Life Science Second Quarter
- 2. LEARNING TARGETS 1. I can identify the sequence of events of the history of life on earth; 2. I can name the pieces of evidence on the evolution of life on earth;
- 3. LIFE
- 16. 16 07/30/2025 Add a footer HOW DID LIFE BEGIN? 1. SPECIAL CREATION
- 17. 17 07/30/2025 Add a footer Creationist theory assumes that a supernatural being such as a divine God responsible for creating life. Perpetuated by the teachings of major religions, this theory accepted by the biblical account of creation as stated in the Book of
- 18. 18 07/30/2025 Add a footer 2. PANSPERMIA
- 19. 19 07/30/2025 Add a footer
- 20. 20 07/30/2025 Add a footer HOW DID LIFE BEGIN? Alexander Ivanovich Oparin, a Soviet biochemist was notable for his theories about the origin of life.
- 21. 21 07/30/2025 Add a footer Hypothesized that: ▪ The Earth’s atmosphere was extremely reducing in its early stages of development. ▪ This means that the atmosphere had an excess of negative charge and could cause reducing reactions by adding electrons to compounds. ▪ These organic compounds could have undergone a series of reactions leading to more and more complex molecules.
- 22. 22 07/30/2025 Add a footer • Organic molecules could have formed from simple inorganic molecules. ▪ These molecules formed colloid aggregates, or ‘coacervates,’ in an aqueous environment. • These coacervates were able to absorb and assimilate organic compounds from the environment in a way reminiscent of metabolism ▪ They would have taken part in
- 23. 23 07/30/2025 Add a footer HOW DID LIFE BEGIN? John Scott Haldane, a physiologist is famous for intrepid self experimentation which led to many important discoveries about human body and the nature of gases.
- 24. 24 07/30/2025 Add a footer Hypothesized that: ▪ The early stages of Earth’s atmosphere was reducing, which could catalyze reactions that would form more complicated organic molecules from simpler molecules. ▪ The oceans served as a huge cooking pot where, powered by the sun or lightning, chemical reactions could occur in an aqueous environment to form a huge diversity of organic compounds. ▪ The primordial sea served as a vast chemical laboratory powered by solar energy.
- 25. 25 07/30/2025 Add a footer The atmosphere was oxygen free, and the combination of carbon dioxide, ammonia and ultraviolet radiation gave rise to a host of organic compounds; ▪ The sea became a ‘hot dilute soup’ containing large populations of organic monomers and polymers. ▪ Groups of monomers and polymers acquired lipid membranes, and that further developments eventually led to the first
- 26. 26 07/30/2025 Add a footer
- 27. 27 07/30/2025 Add a footer Haldane coined the term ‘prebiotic soup’ or ‘prebiotic atmosphere’ that consisted of an abundance of methane, ammonia and water. This term became a powerful symbol of the Oparin-Haldane view of the origin of life. According to the primordial soup theory proposed by Alexander Oparin and John Haldane, life started in a primordial soup of organic molecules. Some form of energy from lightning combined with the chemicals in the atmosphere to make the building blocks of
- 28. 28 07/30/2025 Add a footer EARLY FORMS OF LIFE MICROFOSSILS are fossils that contain the remains of tiny plants and animals.
- 29. 29 07/30/2025 Add a footer EARLY FORMS OF LIFE PROKARYOTES the remains of organisms do not have a nucleus They are known to be the earliest forms of life. They have survived the extreme conditions of the early environment
- 30. 30 07/30/2025 Add a footer EARLY FORMS OF LIFE PHOTOSYNTHETIC ORGANISMS -make their own food by utilizing the energy from the sun and the carbon dioxide in the atmosphere.
- 31. 31 07/30/2025 Add a footer CYANOBACTERIA are the first photosynthetic organisms to form. Their microfossils are among the easiest to recognize.
- 32. 32 07/30/2025 Add a footer How did multicellular organisms evolve? Multicellular organisms are believed to have evolved from unicellular eukaryotes. From colonial aggregates, the organisms evolved to form multicellular organisms through
- 33. 33 07/30/2025 Add a footer Protozoans, sponges and fungi came to being. The first fossilized animals which were discovered 580 million years ago were soft-bodied. The continuous process of cell specialization brought the emergence of complex and diverse plants and animals,
- 36. GEOLOGIC TIME SCALE ON THE HISTORY OF LIFE
- 37. Add a Slide Title - 1