Theories on the Origin of Life PDF

Summary

This document outlines various theories about how life began on Earth. It presents different viewpoints, from special creation to modern theories like abiogenesis. It also touches upon the characteristics of living things.

Full Transcript

Theories on the Origin of Life Life “The ability of an organism to reproduce, grow, and produce energy through chemical reactions to utilize the outside materials.” Origin of Life Theory of Special Creation All living organisms were created same day...

Theories on the Origin of Life Life “The ability of an organism to reproduce, grow, and produce energy through chemical reactions to utilize the outside materials.” Origin of Life Theory of Special Creation All living organisms were created same day [NO DIFFERENCE IN THEIR Theory of APPEARANCE]. Special They were created in the present form [NO Creation EVOLUTION]. (Beliefs) Their bodies and organs are fully developed to meet the requirement to run the life [NO ADAPTATION] It was purely based on religious belief. Theory of There was no experimental evidences to support Special the assumptions. Creation The age of different fossils proves that living (Objections) organism appear on earth in different time frame. Abiogenesis Theory of In ancient Egypt, it was believed that frog, snake, crocodiles appear in the mud of nile Spontaneous river warmed with sun. Generations (Beliefs) Van Helmont claimed that he can produce mice from the dirty shirt and handful of wheat grains kept in dark cupboard in 3 weeks. Abiogenesis Theory of Spontaneous Hair of horse tail dipped in the water gives rise Generations to horsehair worm, Gordius. (Beliefs) Fly larvae develops on rotten meat. Abiogenesis Gordius sp. rise to horsehair worm, Gordius. Fly larvae develops on rotten meat. Redi’s Experiment Theory of Spontaneous Generations (Objections) Spallanzani’s Experiment Open flask Theory of Growth of Spontaneous Bacteria Generations Sealed flask (Objections) No Growth Boiled Broth Incubation Louis Pasteur’s Experiment Theory of Spontaneous Generations (Objections) Theory of Catastrophism Life is originated by the creation and it is followed by catastrophe due to geographical disturbances Theory of Theory of panspermia or spore theory”. Cosmozoic Richter and Arrhenius The theory assumes that life was present in the form of resistant spores and appeared on earth from other planet. Steady state theory Theory of Eternity of This theory assumes that life had no beginning Life or end. It believes that life has ever been in existence and it will continue to be so ever. Physico-Chemical Theory A.I. Oparin and J.B.S Haldane Modern Theory Spontaneous generation of life under the present environment is not possible. Earth’s atmosphere ~1 billion years is very different from the current conditions. Primitive earth’s atmosphere was reducing in nature. Chemical Theory A.I. Oparin and J.B.S Haldane Modern Under these conditions, the chemical molecules Theory (inorganic molecules) react with each other through a series of reactions to form organic substances and other complex biomolecules. The solar energy and UV radiation provided the energy for the chemical reactions. Chemical Theory Modern Theory Proven by Miller through his experiment Hadean Eon Modern Chemical Theory Theory Theories on Enumerate the different theories on the origin of the Origin of life. Life Characteristics of Living Things CHARACTE RISTICS OF What makes an organism alive? LIVING THINGS A distinctive characteristic of a living organism from dead organism or non-living thing, as Life specifically distinguished by the capacity to grow, metabolize, respond (to stimuli), adapt, and reproduce. Organization – Organisms are highly organized, CHARACTE coordinated structures that consist of one or more RISTICS OF cells. LIVING THINGS METABOLISM – chemical reactions and energy transformations which are needed in the maintenance of cell organization, growth, repair and other activities of the CHARACTE cell RISTICS OF Catabolism breaks down organic matter LIVING Anabolism uses energy to construct components of THINGS cells CHARACTE RISTICS OF METABOLISM LIVING THINGS GROWTH AND DEVELOPMENT Growth - An irreversible increase in the size of CHARACTE an organism or part of an organism RISTICS OF Development - a progression from a simpler to a more advanced, mature, or complex form or LIVING stage. THINGS GROWTH AND DEVELOPMENT CHARACTE RISTICS OF LIVING THINGS MOVEMENT/LOCOMOTION Tropism the turning of all or part of an organism in a particular direction in response to an external CHARACTERI stimulus. STICS OF Nastic movement LIVING the direction of the response is not dependent on the THINGS direction of the stimulus. IRRITABILITY –ability to respond to stimuli CHARACTE Protoplasm, the physical basis of animal and plantlife, has among other characteristics that RISTICS OF of irritability to several classes of stimuli furnished by its environment. LIVING It reacts to these stimuli by adjustments, many of THINGS which are accomplished by motion or contraction, and to others by metabolic changes. IRRITABILITY CHARACTE RISTICS OF LIVING THINGS REPRODUCTION – perpetuation of organisms CHARACTE Asexual reproduction RISTICS OF Sexual reproduction LIVING THINGS ADAPTATIONS– traits that enhance the individual’s ability to survive in a particular environment CHARACTE RISTICS OF LIVING THINGS ADAPTATIONS CHARACTE RISTICS OF LIVING THINGS LIVING THINGS POSSESS GENES AND THE MEANS TO USE IT CHARACTE RISTICS OF LIVING THINGS FORM AND SIZE CHARACTERI STICS OF LIVING THINGS CHEMICAL COMPOSITION C,H,O,N CHARACTERI STICS OF LIVING THINGS HOMEOSTASIS – ability of the organism to maintain the internal environment. CHARACTERI STICS OF LIVING THINGS

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