Chapter 1 - Science and the Origin of Life.pdf

BOTANY Ms. Sofia Dela Peña OUTLINE SCIENCE AND THE ORIGIN OF LIFE Science and its branches Theories of the Origin of Life Characteristic of Living and Non-Living Things Difference between Plants and Animals Science and its branches SCIENCE A branch of knowledge or study d...

BOTANY Ms. Sofia Dela Peña OUTLINE SCIENCE AND THE ORIGIN OF LIFE Science and its branches Theories of the Origin of Life Characteristic of Living and Non-Living Things Difference between Plants and Animals Science and its branches SCIENCE A branch of knowledge or study dealing with a body of facts or truths systematically arranged Scientia – “Knowledge”  SCIENCE Natural Social Applied Science Science Science Physical Earth Biological - Sociology Science Science Science - Agronomy - History - Agriculture - Political - Education Science - Botany - Chemistry -Astronomy - Zoology - Physics -Geology - Genetics - Math - Anatomy Science and its branches NATURAL SCIENCE a branch of science that deals with the physical and natural world. physics, chemistry, geology, and biology. ○ Science and its branches The Physical Sciences Physics: The study of matter and energy and the interactions between them. Physicists study such subjects as gravity, light, and time. Chemistry: The science that deals with the composition, properties, reactions, and the structure of matter. Science and its branches The Earth Sciences Geology: The science of the origin, history, and structure of the Earth, and the physical, chemical, and biological changes that it has experienced or is experiencing. Oceanography: The exploration and study of the ocean. Science and its branches The Earth Sciences Meteorology: The science that deals with the atmosphere and its phenomena, such as weather and climate. Astronomy: The study of the universe beyond the Earth's atmosphere. Science and its branches The Life Sciences (Biology) Botany: The study of plants. Zoology: The science that covers animals and animal life. Genetics: The study of heredity. Medicine: The science of diagnosing, treating, and preventing illness, disease, and injury. Examples of Overlapping Science Physics + Chemistry = Physical Chemistry Biology + Chemistry = Biochemistry = Organic Chemistry Geology + Chemistry = Geochemistry Astronomy + Physics = Astrophysics Biology + Geology = Paleontology Geology + Astronomy = Astrogeology Biology + Astronomy + Physics = Astronautics  Curiosity Aristotle (384-322 B.C.) Theories of the Origin of Life Several attempts have been made from time to time to explain the origin of life on earth. As a result, there are several theories which offer their own explanation on the possible mechanism of origin of life. Theories of the Origin of Life Theory of Special Creation Theory of Catastrophism Theory of Panspermia Theory of Chemical Evolution Theory of Spontaneous Generation Theory of Evolution Theory of Special Creation All the different forms of life that occur today on planet earth, have been created by God, the almighty. This idea is found in the ancient scriptures of almost every religion. The theory of Special Creation was purely a religious concept, acceptable only on the basis of faith. Theory of Special Creation It has no scientific basis. ○ Hindu mythology, Lord Brahma, the God of Creation, created the living world in accordance to his wish. ○ Christian belief, God created this universe, plants, animals and human beings in about six natural days. ○ Sikh mythology, says that all forms of life including human beings came into being with a single word of God. Theory of Catastrophism It is simply a modification of the theory of Special Creation. It states that there have been several creations of life by God, each preceded by a catastrophe resulting from some kind of geological disturbance different from that of previous ones. A French scientist Georges Cuvier (1769-1832) and Orbigney (1802 to 1837) were the main supporters of this theory. Cosmozoic Theory (Theory of Panspermia) According to this theory, life has reached this planet Earth from other heavenly bodies such as meteorites, in the form of highly resistance spores of some organisms. This idea was proposed by Richter in 1865 and supported by Arrhenius (1908) and other contemporary scientists. The theory did not gain any support since it lacks evidence, hence it was discarded. Theory of Chemical Evolution This theory is also known as Materialistic Theory or Physico-chemical Theory. According this theory, Origin of life on earth is the result of a slow and gradual process of chemical evolution that probably occurred about 3.8 billion years ago. This theory was proposed independently by two scientists - A. I. Oparin, a Russian scientist in 1923 and J.B.S Haldane, an English scientist, in 1928. Theory of Spontaneous Generation Also known as Abiogenesis. The natural process of life arising from non-living matter such as simple organic compounds. This theory assumed that living organisms could arise suddenly and spontaneously from any kind of non-living matter. One of the firm believers in spontaneous generation was Aristotle, the Greek philosopher (384-322 BC). Theory of Spontaneous Generation Earth's surface and atmosphere during the first billion years of existence, were radically different from that of today's conditions. The primitive earth's atmosphere was a reducing type of atmosphere and not oxidizing type. The first life arose from a collection of chemical substances through a progressive series of chemical reactions. Solar radiation, heat radiated by earth and lighting must have been the chief energy source for these chemical reactions. Theory of Spontaneous Generation Aristotle ○ He believed that dead leaves falling from a tree into a pond would transform into fishes and those falling on soil would transform into worms and insects. ○ He also held that some insects develop from morning dew and rotting manure. Egyptians believed that mud of the Nile river could spontaneously give rise to many forms of life. Theory of Spontaneous Generation The theory of Spontaneous Generation was disproved in the course of time due to the experiment conducted by Fransisco Redi (1665), Spallanzani (1765) and later by Louis Pasteur (1864) in his famous Swan neck experiment. This theory was disapproved, as scientists gave definite proof that life comes from pre-existing life. Theory of Evolution Charles Darwin Evolution by means of natural selection Evolution by natural selection is a process inferred from three facts about populations: ○ more offspring are produced than can possibly survive ○ traits vary among individuals, leading to different rates of survival and reproduction ○ trait differences are heritable. Theory of Evolution When members of a population die they are replaced by the progeny of parents better adapted to survive and reproduce in the environment in which natural selection takes place. Characteristic of Living and Non-living Things Living ○ anything that is or has ever been alive Non-living ○ anything that is not now nor has ever been alive  Difference between Plants and Animals Plants Animals They are rooted in one place and Most animals have the ability to do not move on their own. move fairly freely. Animals cannot make their own food Plants contain chlorophyll and can and are dependent on plants and make their own food. other animals for food. Animals give off carbon dioxide Plants give off oxygen and take in which plants need to make food and carbon dioxide given off by take in oxygen which they need to animals. breathe. Plants cells have cell walls and Animal cells do not have cell other structures differ from those walls and have different of animals. structures than plant cells. Animals have a much more highly Plants have either no or very developed sensory and nervous basic ability to sense. system.