Part I and Chapter 1 Biology Sixth Edition Raven/Johnson (c) The McGraw-Hill Companies, Inc.

BIOLOGY “Bios” “-ology” Life Study of You cannot escape biology! -It’s all around you!!!

The Properties of Life Life is diverse yet all living things share five properties: 1)Cellular Organization – all organisms consist of one or more cells 2)Order (Fig. 1.2) – physical structure of organisms 3)Sensitivity – respond to stimuli 4)Growth, development, and reproduction 5)Energy Utilization – take in energy to do work 6)Evolutionary Adaptation – interactions with environment and other organisms that influence survival 7)Homeostasis – maintain constant internal conditions different than surrounding environment

Hierarchical Organization

Groups of individuals of a species are called populations. Populations of different species that interact make up communities. Communities plus the physical habitat form ecosystems.

B E E E      B = Biosphere E = Ecosystems Circles = Communities* Dots = Species/Populations * Includes abiotic features/ physical environment Organization of the Biosphere (Earth) Interdependence

The Nature of Science (Deductive vs. Inductive Reasoning) Deductive Reasoning –Applies known general principles to predict specific results Using known principles to answer a question

Inductive Reasoning –Uses specific observations to construct general scientific principles –Most biological studies use inductive reasoning Timing how long it takes a 1 kilogram weight to fall a known distance. –Determine the time (with specific observation and experimentation) it takes a one kilogram weight to travel a certain distance is inductive reasoning (a general principle) –Using that principle to determine how tall a building is deductive reasoning.

How Science is Done (The Scientific Method) An Observation is made A Hypothesis is developed Experimentation is done A Conclusion is made A Theory is developed based on many conclusions

-Theory of Evolution

Darwin’s Evidence – Natural Selection 1.Principle’s of Geography (Charles Lyell 1830) First outlined that the Earth as probably older than a few thousand years old He wrote of an ancient world of strange plants and animals 2.Fossils Fossils most closely resembles individuals from the area the fossil was found. Progressive changes in characteristics found in rock strata. 3.Oceanic Islands Few species, but groups seem to be closely related Species show strong affinity for those on the mainland

Inventing the Theory of Natural Selection Essay on the Principle of Population (Thomas Malthus, 1798); more offspring produced than survive Artificial and Natural Selection Alfred Russell Wallace – independently came up with same idea Publication of Darwin’s ideas: 1859

However, his argument was so compelling, his ideas were almost completely accepted by the intellectual community of Great Britain after the 1860s

Modern Evidence for Evolution The Fossil Record The Age of the Earth (4.5 billion years old, not a few thousand!) The Mechanism of Heredity (Genes) Comparative Anatomy (Homologous vs. Analogous; figure 1.13) Molecular Evidence (DNA; figure 1.14) Molecular Clocks (Figure 1.15) Phylogenetic Trees

Homologous Analogous Wings on a bat and a butterfly

The End.