1.Origin Of Life.pptx
- 1. COURSE CONTENTS ECOLOGY 1.Origin of Life (Evolution) 2.Introduction to Animal Kingdom: Sponges, Cnidarians, Mollusks, Flatworms, Annelids, Roundworms, Arthropods, Echinoderms. 3.Phylum Chordata: Amphibians, Reptiles, Birds, Fish and Mammals 4.Construction of Phylogenetic Trees On the Basis Of Morphology And Molecular Markers BIODIVERSITY 5.Kingdom Plantae: Plant Biodiversity – History, Importance, Usefulness and Evolution; 6.Importance Of Plants and their Domestication; 7.Conservation (In-situ and Ex-situ) 8.Improvement Of Crops; 9.Impact Of Environment On Loss Of Genetic Diversity And Speciation; EVOLUTION 10.Evolution Of Microbes, Plants And Animals; 11.Methods Of Studying Evolution 12.Environmental Ethics. Reference Books: 1.“Biology: The Unit and Diversity OF Life” By Ralph Taggart, Third Edition (Available in UCP Library) 2.“Essential Biology with Physiology” by Campbell, Reece, Simon, Pearson Publishers, Second Edition (Available in UCP Library) 3."Environmental Biology” By Mathew R. Fisher (pdf available) 4.“Ecology: The Experimental Analysis of distribution and Abundance” by Charles J. Krebs, Pearson Publishers (Available in UCP Library)
- 3. Books & Chapter Number ◦ Book Name: Campbell Essential Biology with Physiology ◦ Chapter15 (Origin of Life) ◦ Book Name: Biodiversity and Unit of Life ◦ Chapter 19 (Origin of Life)
- 8. ◦ It is presumed that the universe came into existance with a single titanic explosion called big bang about 15000 million year ago. ◦ The fragments of the fire ball expanded and cooled to give rise to many celestial bodies. ◦ This resulted in the formation of solar system consisting of sun and planets. ◦ The Earth originated about 4.6 billion years ago. ◦ Earlier life was thought to be created by some super natural power.
- 10. Theories 1. THEORY OF SPECIAL CREATION 2. PANSPERMIA (COSMOZOA) 3. ABIOGENESIS 4. BIOGENESIS 5. DEEP SEA HYDROTHERMAL VENTS 6. BIOCHEMICAL EVOLUTION/ELECTRIC SPARK (UREY-STANELY EXPERIMENT) 7. MOLECULES OF LIFE MET ON CLAY
- 19. A Four-Stage Hypothesis for the Origin of Life According to one hypothesis for the origin of life, the first organisms were products of chemical evolution in four stages: (1) the abiotic (nonliving) synthesis of small organic molecules, such as amino acid and nucleotide monomers; (2) the joining of these small molecules into macromolecules, including proteins and nucleic acids; (3) the packaging of all these molecules into pre-cells, droplets with membranes that maintained an internal chemistry different from the surroundings; and (4) the origin of self-replicating molecules that eventually made inheritance possible. This is all speculative, of course, but what makes it a valid scientific hypothesis is that it leads to predictions that can be tested in the laboratory. Let’s take a closer look at each of these four stages.
- 24. 7. MOLECULES OF LIFE MET ON CLAY • The first molecules of life might have met on clay, according to an idea elaborated by organic chemist Alexander Graham Cairns-Smith at the University of Glasgow in Scotland. These surfaces might not only have concentrated these organic compounds together, but also helped organize them into patterns much like our genes do now. • The main role of DNA is to store information on how other molecules should be arranged. Genetic sequences in DNA are essentially instructions on how amino acids should be arranged in proteins. Cairns-Smith suggests that mineral crystals in clay could have arranged organic molecules into organized patterns. After a while, organic molecules took over this job and organized themselves.
- 26. CONCLUSION ◦ All the evidence gathered thus far has revealed a great deal about the origin of life, but there is still much to learn. ◦ Numerous scenarios have been explored for many years, but there is still a large gap between what is known and what is unknown. ◦ Because of the enormous length of time and the tremendous change that has occurred since then, much of the evidence relevant to origins has been lost and we may never know certain details. ◦ Nevertheless, many of the gaps in our knowledge (gaps that seemed unbridgeable just 20 years ago) have been filled in recent years, and continuing research and new technologies hold the promise of more insights.