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General Zoology


Dr. Christopher M. Ritzi. Office: WSB 220. Office hours: M&F 10-12, T 2-4, or by appt. ... Unpolluted lichen-covered tree Soot-covered tree. Natural Selection ... – PowerPoint PPT presentation

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Title: General Zoology

General Zoology
  • BIOL 1402
  • Dr. Christopher M. Ritzi
  • TR 11- 1215 WSB 201

  • Review Syllabus
  • Chapter 1 Introduction and Evolution

  • Dr. Christopher M. Ritzi
  • Office WSB 220
  • Office hours MF 10-12, T 2-4, or by appt.
  • Phone 837-8420
  • Email
  • Webpage http//
  • Lecture 11-1215 TR WSB 201
  • Labs 1-300pm, 3-500pm, 7-900pm Wednesday WSB
  • 2-400pm, 4-600pm Thursday WSB 111

General ZoologyBIOL 1402
  • Chapter 1
  • Life Biological Principles and the Science of

What is Life?
  • Life is thought of, or defined by, possessing 7
    unique qualities
  • Chemical uniqueness
  • Complexity and hierarchical organization
  • Reproduction
  • Possession of a genetic program
  • Metabolism
  • Development
  • Environmental interaction

Properties of Life
  • Chemical uniqueness Living systems demonstrate
    a unique and complex molecular organization.
  • Complexity and hierarchical organization Living
    systems are made of various levels of complexity.
  • Molecules, cells, organisms, populations and
  • Each level has hierarchy as well organisms can
    be made of cell, tissues, organs, etc.

Properties of Life
  • Reproduction Living systems can reproduce
  • 4 levels molecular, cellular, organismal, and
  • Possess a genetic program A genetic program
    provides fidelity of inheritance.
  • Nucleic acids make DNA.
  • The sequence of DNA in an organism is its genetic

Properties of Life
  • Metabolism Living organisms maintain themselves
    by obtaining nutrients from their environments.
  • Development All organisms pass through a
    characteristic life cycle.
  • Environmental interaction All animals interact
    with their environments.

Life Obeys Physical Laws
  • Laws of Thermodynamics
  • 1st law of conservation of energy
  • Energy is neither created nor destroyed, but can
    be transformed from one form to another.
  • 2nd law of entropy
  • Physical systems tend to move toward a state of
    greater disorder, chaos, or entropy.

What is Zoology?
  • The scientific study of animals.
  • Two Major Goals
  • Reconstruct a phylogeny of life and determine how
    organisms are interrelated to one another.
  • Understand the historical processes that generate
    and maintain diversity through history

Principles of Science
  • Essentially a way of gaining experience ie.
  • Science is experience (knowledge) gained through
    using the scientific method and then these
    results are communicated with others.

Essential Characteristics of Science
  • It is guided by natural laws.
  • It has to be explanatory by reference to natural
  • It is testable against the empirical world.
  • Its conclusions are tentative, that is, are not
    necessarily the final word.
  • It is falsifiable.

Assumptions of Science
  1. What we receive with our five basic senses
    represents objective reality.

Assumptions of Science
  • This basic reality functions according to
    certain, basic principles and natural laws that
    remain constant over time.
  • Examples

Copernican principle
Boyles law The pressure of an ideal gas is
inversely proportional to the volume of the gas
at constant temperature.
Evolution by Natural Selection
Assumption of Science
  • That there is a cause and effect for observable
    events ( at least at some level).

Assumptions of Science
  • We can understand the observable universe and
    natural laws through observation and testing of
    hypotheses of cause and effect.
  • The procedures for testing these hypotheses are
    the scientific method. The test should be
  • Repeatable
  • Measurable

Limitations of Science
  • Cannot prove or disprove the existence of a
    unique event or one that was outside the known
    laws of the universe.
  • Works with probabilities.
  • Cannot prove a negative
  • Example of personal research

The Scientific Method
  • The hypothetico-deductive method
  • Generate a hypothesis
  • Test the hypothesis
  • Analyze data and interpret data to determine
    whether to maintain the hypothesis.
  • If hypothesis is maintained, try to test another
    way to better enforce hypothesis.
  • If hypothesis is rejected, use data to formulate
    new hypothesis and repeat.

  • An explanation, an educated guess, a hunch, a
    subliminal understanding, - (but in the
    scientific process, one that is worth spending a
    great deal of energy and time on validating).

Testing a Hypothesis
  • Design of a test of the hypothesis
  • Observation
  • Repeatable
  • Comparison with control groups (no treatments)
    and/or different treatments or conditions.
  • Analysis and communication.

Some Definitions
  • Theory Well supported hypothesis of a cause and
    effect process that explains many phenomena. Not
    just a speculation.
  • Keplars Theory of Planetary Motion One
    mathematical relationship which explains many,
    many celestial phenomena.

Some Definitions
  • Paradigm - A widely accepted theory or group of
    interrelated theories which guide many research

Some Definitions
  • Scientific Revolutions The overthrow of a long
    held paradigm and rearrangement and formulations
    of scientific ideas and directions.
  • Continental Drift in the late 1950s

Proximate versus Ultimate Causes
  • Proximate cause Immediate cause of an event or
    function. The mechanisms and the how and what
  • Ultimate cause Long term reasons for a
    phenomena. Why questions. In Biology these
    are often evolutionary questions.

Proximate versus Ultimate Causes
  • Example Why do we have a fever?
  • Proximate cause Rapid increase in metabolism
    and dilation of blood vessels initiated by
    invasion of foreign microbes.
  • Ultimate cause Fevers are adaptive physiologic
    mechanisms with beneficial effects which have
    evolved to combat infections.

Experimental vs. Comparative Methods
  • Experimental sciences Address proximate causes
    of how systems work.
  • For example
  • Expression of a gene for color blindness.
  • Effect of caffeine on the cellular processes of
    the small intestine.
  • Effect of prey density on foraging patterns of
    Siberian tigers

Experimental vs. Comparative Methods
  • Experimental sciences Consist of 3 steps.
  • Predict how a system will respond to a
  • Cause a disturbance.
  • Compare observed results to predicted results
  • Typically done with controls (undisturbed
    systems) and other treatments (replicates) to
    reduce results due to random chance.

Experimental vs. Comparative Methods
Hamadrayas Baboon - lt 2000 ft elevation
  • Comparative Biological Sciences Address
    ultimate causes of how systems work. However, we
    cant go back in time and run evolution under
    controlled conditions. Instead we have to
    compare related species.

Gelada baboon - gt 5000 ft elevation
Darwins (and Wallaces) Theory of Evolution
  • Perpetual Change
  • Common Descent
  • Multiplication of species
  • Gradualism
  • Natural Selection

Alfred Wallace
Darwins Theory of Evolution
  • Perpetual Change - Species are not fixed, but
    are often changing (commonly at different rates).
    Through the generations, most common forms
    change, as shown in the fossil record.

Darwins Theory of Evolution
  • Common descent All forms of life had a common
  • Phylogeny Evolution produces a branching
    structure and the form this takes is called a

Darwins Theory of Evolution
  • Multiplication of Species New species form by
    splitting and transforming older species.
  • Typically the result of isolation or separation,
    and based primarily upon reproductive isolation
  • The evolutionary processes guiding speciation is
    still actively studied.

Darwins Theory of Evolution
  • Gradualism Evolution is a gradual and slow
    process (by human standards) and large, rapid
    changes are usually not common in the evolution
    on a group of organism.
  • Most large changes over time occur through a
    series of small changes.
  • Large changes tend to be harmful for organisms,
    although not always

Natural Selection
  • Based on the idea that all animals possess
    variation, which is heritable. These differences
    will be passed on to future generations, with
    some variations being more success and increasing
    in frequency over time.
  • Adaptation is evident in many examples.
  • Increased insect resistance to pesticides.
  • Industrial melanism in the peppered moths of

Unpolluted lichen-covered tree Soot-covered
Natural Selection
  • Homologous Structures different structures
    modified from the same basic structure.
  • Arm of a human
  • Arm of a cat
  • Wing of a bat
  • Fin of a whale
  • Leg of a horse

Mendelian Heredity
  • Gregor Mendel (early 1800s) studied inheritance
    in plants. Found that inheritance was hard and
    appeared that something material was passed from
    generation to generation.

Mendelian Heredity
  • Gregor Mendel (early 1800s) found that there was
    segregation of genetic factors and that they were
  • P1 ? F1 ? F2 -- Factors did not blend.

Mendelian Heredity
  • Found that Genetic factors were in pairs
  • The importance of Mendels work was not realized
    until early 1900s during neo-Darwinism.
  • These factors are known called genes.

Contributions to Cell Biology
  • With the development of good microscopes, it was
    discovered that indeed that cells had two copies
    of chromosomes.
  • Observations were made of meiosis and how the
    chromosomes independently and randomly segregated
    in new daughter cells.
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