Life Science I 83.101.102 Dr. Ekaterina (Kate) Vorotnikova Office: 413b E-mail: Ekaterina_Vorotnikova@uml.edu - PowerPoint PPT Presentation

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Life Science I 83.101.102 Dr. Ekaterina (Kate) Vorotnikova Office: 413b E-mail: Ekaterina_Vorotnikova@uml.edu

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Life Science I 83.101.102 Dr. Ekaterina (Kate) Vorotnikova Office: 413b E-mail: Ekaterina_Vorotnikova_at_uml.edu Lecture 2 Evolution, biosphere, and science – PowerPoint PPT presentation

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Title: Life Science I 83.101.102 Dr. Ekaterina (Kate) Vorotnikova Office: 413b E-mail: Ekaterina_Vorotnikova@uml.edu


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Life Science I83.101.102Dr. Ekaterina (Kate)
VorotnikovaOffice 413bE-mail
Ekaterina_Vorotnikova_at_uml.edu
  • Lecture 2
  • Evolution, biosphere, and science
  • (pages 9-16)

2
 Mader, Essentials of Biology 2E with CONNECT
Plus Access Card
Essentials of Biology Second Edition Sylvia S.
Mader with McGraw-Hill Connect Biology
3
Student registration info
Course Life Science 83.101.102 
Instructor Ekaterina Vorotnikova  
Section Spring 2010 mwf 9 am 
online registration instructions Go to the
following Web addressand click the "register
now" button
http//connect.mcgraw-hill.com/class/e_vorotnikova
_spring_2010_mwf_9_am
(http//connect.mcgraw-hill.com/class/e_vorotnikov
a_spring_2010_mwf_9_am)
Web addresses cannot contain spaces. Use
lowercase letters or numbers or special
characters ( '-' and '_' ) only.
This is a unique address for Spring 2010 mwf 9 am
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Assignments for a 1/25 week 1. Lec 1
Assignment 2. Quiz 1 3. Work on LearnSmart
study modulus to study chapter 1 until Feb.2 Due
on Monday Feb. 1 at 1100 p.m.
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Final grade
  • Grade for exams 50
  • Grade for assignments 30 (20 for assignments
    10 LearnSmart activity)
  • Grade for quizzes 20
  • (100 points max 5 points for attendance.)
  • Total number of points -105.
  •  

9
Evolution, the Unifying Concept of Biology
  • Despite diversity, organisms share the same basic
    characteristics
  • Composed of cells organized in a similar manner
  • Their genes are composed of DNA
  • Carry out the same metabolic reactions to acquire
    energy
  • This suggests that they are descended from a
    common ancestor

10
Classification
Taxonomy Discipline of identifying and
classifying organisms according to certain
rules Hierarchical levels (taxa) based on
hypothesized evolutionary relationships Levels
are, from least inclusive to most
inclusive Species, genus, family, order, class,
phylum, kingdom, and domain A level (e.g.
phylum) includes more species than the level
below it (e.g. class), and fewer species than the
one above it (e.g. kingdom)
11
Scientific Names
  • Binomial nomenclature (two-word names)- used to
    assign each organism with two part name e.g. Homo
    Sapience
  • Universal
  • Latin-based
  • First word represents genus of organism e.g. Homo
  • Second word is specific epithet of a species
    within the genus e.g. Sapience
  • Always italicized as a Genus species (Homo
    sapiens)
  • Genus may be abbreviated e.g. Escherichia coli as
  • E. coli

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Taxonomy
  • Leopard Panthera pardus
  • Jaguar Panthera onca
  • Tiger Panthera tigris
  • Lion Panthera leo
  • Domain Eukarya
  • Kingdom Animalia 
  •  Phylum Chordata 
  •  Class Mammalia 
  •  Order Carnivora 
  •  Family Felidae 
  •  Genus Panthera 
  •  Species P. pardus P. onca P. tigris P. leo

14
Crossota millsae, a brilliant red and purple
jellyfish found at a depth of 2000m in the Arctic
Ocean
The small blue jelly, a type of Narcomedusae, is
new to science.
Rhacophorus suffry
Miniature Muntjac, Muntiacus putaoensis
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Domains
Common ancestor
  • Bacteria Microscopic unicellular prokaryotes
  • Archaea Bacteria-like unicellular prokaryotes
  • Extreme aquatic environments
  • Eukarya Eukaryotes Familiar organisms

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PROKARYOTES
EUKARYOTES
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Prokaryotic cell
Eukaryotic cell
DNA (no nucleus)
Membrane
1-10 µm
Nucleus (contains DNA)
10-100 µm
Organelles
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Evolution, the Unifying Concept of Biology
In 1859, Charles Darwin (12 February 1809 19
April 1882) published On the Origin of Species by
Means of Natural Selection, presenting a strong,
logical explanation of descent with modification,
evolution by the mechanism of natural selection.
Evolution is descent of species from common
ancestors, with genetic modifications that make
each species more suited to its environment.
Randal Keynes, 62, is the great-great-grandson of
Charles Darwin. He is also the author of the book
Darwin, His Daughter, and Human Evolution,
inspiration for the new film Creation, starring
Paul Bettany and Jennifer Connelly. The film
opened last Friday and gets a wider release Jan.
29.
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Natural Selection
  • A process in which steps 1-3 result in population
    adapted to the environment (4)
  • The members of a population have heritable
    variations differences in their DNA that can be
    passed from one generation to the next.
  • The population produces more offspring than the
    resources of an environment can support.
  • The more adapted individuals survive and
    reproduce to a greater extent than those that
    lack the adaptations.
  • Across generations, a larger proportion of the
    population becomes adapted to the environment.

22
Descent with Modification.
The various species of Hawaiian honeycreepers all
evolved from one species of finch which
originated in North America and arrived in the
Hawaiian Islands millions of years ago. They have
different bill shapes adapted to different kinds
of food flower nectar, seeds, fruits, insects..
All honeycreepers still share certain
characteristics from common finch ancestor body
shape, nesting behavior, etc.
23
Organization of the Biosphere
  • Population - Members of a species within an area
  • Community - A local collection of interacting
    populations
  • Ecosystem A community plus its physical
    environment
  • How chemicals are cycled and re-used by organisms
  • How energy flows, from photosynthetic plants to
    top predators

24
A grassland, terrestrial ecosystem
1. Chemicals cycle through an ecosystem. 2.
Energy flows through ecosystem and dissipates as
heat.
What are two most biologically diverse ecosystems?
25
Science A Way of Knowing
Biologists
  • Biology is the scientific study of life.

26
Flow diagram for the scientific method
  • Scientific method begins with observations.
  • May take advantage of knowledge and experiences
    of other scientists
  • Scientist uses inductive reasoning uses
    creative thinking to combine isolated facts into
    a cohesive whole.
  • Hypothesis possible explanation for an event
  • Consider only those that can be tested.

27
  • Experiments further observations and test
    hypothesis.
  • Good experimental design, all conditions constant
    except experimental variable
  • Test group versus control group
  • Data may suggest correlation.
  • Does not necessarily mean causation
  • Scientists are skeptics
  • Conclusion is the hypothesis supported or not?
  • Experiments and observations must be repeatable.

28
  • Scientific theory
  • Ultimate goal of science is to understand the
    natural world in accepted explanations for how
    the world works.
  • Cell theory, gene theory
  • Theory of evolution is considered a unifying
    concept in biology.
  • Some biologists refer to the principle or law of
    evolution due to over 100 years of support by so
    many observations and experiments.

29
Controlled laboratory experiment to test the
effectiveness of a medication in humans
  • Controlled study
  • Hypothesis
  • Antibiotic B is better than Antibiotic A in
    current use for the treatment of ulcers.

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3 experimental groups Reduce possible
variances by randomly dividing large
group. Control group receives placebo.
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The Scientific Method
  • Begins with observation
  • Hypothesis
  • Experimentation (Purpose is to challenge the
    hypothesis)
  • Often divides subjects into a control group and
    an experimental group
  • Predicts how groups should differ if hypothesis
    is valid
  • Results or Data (Observable, objective results
    from an experiment)
  • The results are analyzed and interpreted
  • Conclusions are what the scientist thinks caused
    the results

33
Scientific Theory
  • Scientific Theory
  • Joins together two or more related hypotheses
  • Supported by broad range of observations,
    experiments, and data
  • Scientific Principle / Law
  • Widely accepted set of theories
  • No serious challenges to validity

34
Biodiversity
  • Biodiversity is variation in life on Earth, in a
    zone of air, land, and water where organisms
    exist (the number of different species)
  • Abundance of species estimated about 15 million.
  • Fewer than 2 mln. have been identified, named and
    classified
  • The variability of their genes, and
  • The ecosystems in which they live
  • Extinction is
  • The death of the last member of a species
  • Estimates of 400 species/day lost worldwide
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