General Zoology

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General Zoology

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

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Outline

• Review Syllabus
• Chapter 1 Introduction and Evolution

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Syllabus

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

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General ZoologyBIOL 1402

• Chapter 1
• Life Biological Principles and the Science of
  Zoology

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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

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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
  species.
• Each level has hierarchy as well organisms can
  be made of cell, tissues, organs, etc.

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Properties of Life

• Reproduction Living systems can reproduce
  themselves.
• 4 levels molecular, cellular, organismal, and
  species
• 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
  code.

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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.

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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.

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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

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Principles of Science

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

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Essential Characteristics of Science

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

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Assumptions of Science

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

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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.
Emc2
Evolution by Natural Selection
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Assumption of Science

• That there is a cause and effect for observable
  events ( at least at some level).

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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

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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

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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.

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Hypothesis

• 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).

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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.

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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.

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Some Definitions

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

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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

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Proximate versus Ultimate Causes

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

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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.

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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

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Experimental vs. Comparative Methods

• Experimental sciences Consist of 3 steps.
• Predict how a system will respond to a
  disturbance.
• 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.

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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
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Darwins (and Wallaces) Theory of Evolution
(1859)

• Perpetual Change
• Common Descent
• Multiplication of species
• Gradualism
• Natural Selection

Alfred Wallace
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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.

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Darwins Theory of Evolution

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

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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.

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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

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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
  England.

Unpolluted lichen-covered tree Soot-covered
tree
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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

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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.

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Mendelian Heredity

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

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Mendelian Heredity

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

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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.