Part I and Chapter 1

BiologySixth 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 = BiosphereE = EcosystemsCircles = Communities*Dots = Species/Populations

* Includes abiotic features/physical environment

Organization of the Biosphere (Earth)

Interdependence

www.nicholls.edu/bayousphere

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

• 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 Selection1. 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.