General Biology Chapter 1: Biology Today
Introduction Dr. Jeffrey P. Thompson Text: Essential Biology
Biology Is All Around US!
What is Biology? The study of life bio- meaning life; -ology meaning study of Structured from molecular level to global Emergent properties of life Mlidi Multidimensional i l- interconnected Can you recognize life?
Properties of life = ALL must be present
Are Viruses Alive? HIV bacteriophage Can you kill a virus?
Many Levels of Life Figure 1.3
Cell Theory All life is cell-based. Living i cells come from other living i cells.
All Cells Obey the Cell Theory
Where did you come from? When were you not alive? Does life begin at birth, fertilization, or sometime else?
Overview of Life s Unity
Cellular Unity All cells use DNA as the chemical material of genes. Genes are the units of inheritance that transmit information from parents to offspring. The language of DNA contains just four letters: A, G, C, T
Unity of Energy Figure 1.4
Overview of Life s Diversity Inspite of the unity there there are differences.
Taxonomy The science of organizing life. Classification system Grouping things by their similarities Visible similarities Molecular similarities A hierarchy Most inclusive i domain Most exclusive - species
The Three Domains of Life Domain Bacteria Domain Archaea The three domains of life are Domain Eukarya Bacteria Archaea Eukarya Kingdom Protista Kingdom Plantae Kingdom Fungi Kingdom Animalia Figure 1.8.1
Most exclusive Taxonomy etiquette Always lists Genus first (capitalized), then The Species (lower case). Both are Italicized or underlined. Most inclusive
Evolution the Scientific way of explaining both the diversity and unity of life.
The Darwinian View of Life The evolutionary view of life came into focus in 1859 when Charles Darwin published The Origin of Species Figure 1.12
Darwin s book developed two main points Descent with modification Natural selection
Natural Selection Darwin was struck by the diversity of animals on the Galápagos Islands He thought of adaptation to the environment and the origin of new species as closely related processes As populations separated by a geographic barrier adapted to local environments, they became separate species
Fourteen species of Galápagos finches have beak shapes adapted to suit their environments Large ground finch Medium ground finch Small ground finch Seed-eaters Large cactus ground finch Sharp-beaked ground finch Cactus ground finch Cactus-flower -eaters Vegetarian finch Bud-eater Small Medium Woodpecker tree finch tree finch finch Large tree finch Mangrove finch Insect-eaters Green warbler finch Gray warbler finch Ground finches Tree finches Warbler finches Common ancestor from South American mainland Figure 1.13
Darwin s Inescapable Conclusion Darwin synthesized the concept of natural selection from two observations that were neither profound nor original Others had the pieces of the puzzle, but Darwin could see how they fit together
Fact 1: Overproduction and struggle for existence Fact 2: Individual variation The inescapable conclusion: Unequal reproductive success It is this unequal reproductive success that t Darwin called natural selection The product of natural selection is adaptation
Natural selection is the mechanism of evolution 1 Population with varied inherited traits 2 Elimination of individuals with certain traits 3 Reproduction of survivors 4 Increasing frequency of traits that enhance survival and reproductive success Figure 1.14
Each species is one twig of a branching tree of life extending back in time Life evolves, sculpted by Natural Selection Giant panda Spectacled bear Sloth bear Sun bear American black bear Asiatic Polar black bear bear Brown bear Ancestral bear Figure 1.11
Observing Artificial Selection Artificial selection is the selective breeding of domesticated plants and animal by humans Figure 1.15
Evolution can scientifically explain the universal architecture of eukaryotic cilia. (a) Paramecium (b) Cells from fallopian tube (c) Cross section of cilium Figure 1.9
Observing Natural Selection There are many examples of natural selection in action The development of antibiotic-resistant bacteria is just one example. Figure 1.16
What is the evolutionary advantage the flower fly exhibits?
Darwin s publication of The Origin of Species fueled an explosion in biological research Evolution, by natural selection, is one of biology s best demonstrated, most comprehensive, and longest lasting theories Evolution is the unifying theme of biology
The Process of Science The word science is derived from a Latin verb meaning to know. Science is a way of knowing. Science developed from people s curiosity about themselves and the world around them.
Two Approaches of Science Discovery Science limits the scope of science to the study of structures and processes that we can observe and measure. Verifiable observations and measurements are the data of discovery science. Darwin s description of animals in South America Dissection of the human body Sequencing of human genome
Experimental Science Experimental Science Use of scientific method to answer questions
Scientific Method a scientific process to achieve knowledge. Figure 1.18
Scientific Method
Scientific Method
Experimental Tests Tests that can simplify observation in nature or the lab because conditions can be manipulated. Testing a falsifiable hypothesis Some questions lie outside the realm of the scientific method. Some questions can t be answered through science. Example Does God exist? Does God not exist?
Experimental Test Set Up Test one prediction of a hypothesis at a time Experimental Group Set up a group that mimics nature in which to compare the experimental groups Control Group (these give you predicted results) Controls lend credibility and believability to your experimental results. Variables one aspect of an object of event being studied.
What is a Theory? A hypothesis s that has stood rigorous o tests and has not been disproved. It is used to interpret more data or observations. Based on evidence known at that time. Scientists continually devise tests to disprove. NOT a speculative idea. Evolution by Natural Selection is a Theory.
Can you think Like a scientist? i King snake (non Venomous) looks Like an eastern Snake (venomous) Why?
Science, Technology, and Society Science and technology are interdependent. New technologies advance science. Scientific discoveries lead to new technologies. For example the discovery of the structure of DNA 50 years ago led For example, the discovery of the structure of DNA 50 years ago led to a variety of DNA technologies.
Genetic engineering g and biotechnology have allowed us to manipulate the DNA and genes of organisms Figure 1.6