Download Zoology Chapter 4 Power Point Notes

Zoology Chapter 4 Power
Point Notes
Ms. K. Cox
Change
• Many groups of people have
considered the idea that
organisms change over time.
• The earliest ideas of evolution
originated with the Greeks,
including Aristotle
Lamarck
• Lamarck was the first to describe a coherent,
scientific theory of evolution, although an
incorrect theory. Lamarck’s theory of inheritance
of acquired characteristics assumed that the
development, or loss of structures, was due to
use, or disuse, of these structures. The problem
with his theory is that there was no mechanism
by which the characters could be passed to the
next generation. Phenotypic change in one
generation would not produce genotypic change
in subsequent generations.
• • Darwin
• The story of Darwin is such an
interesting one. He was initially a
premedical student, and
• like many of our students, found
himself unsuited to this field. He
married his cousin, Emma
Wedgewood, and they had 10 children,
only 7 of which reached maturity.
Do not copy this slide it is just for
information.
• When Darwin embarked on the voyage on the
Beagle, he was only 22 years old. We often
emphasize the importance of this voyage, but
equally important were the 20 years of studies he
conducted later in England that helped shape his
ideas. He studied barnacles for 8 years and wrote
4 huge volumes on them! He was the first
scientist to discover that barnacles were
crustaceans, not molluscs. He also did some
experimental crosses on pigeons, but, unlike
Mendel, he did not conduct enough crosses to
mathematically analyze them.
Darwin’s work
• Darwin was a well-educated member
of the English aristocracy before he
took the position of ship’s naturalist
on the HMS Beagle. During a 5-year
voyage to map the coastlines of
South America, Darwin observed a
wide variety of living animals, and
found many fossils as well.
Darwin’s work
• During his visit to the Galàpagos Islands,
he observed the terrestrial giant tortoises
and the various species of finches found
within the archipelago. Darwin noticed that
the island species exhibited some
morphological similarities, as might be the
case if they had come from the same
starting population, but also exhibited
some morphological differences from each
other, as might be the case if they had
adapted to the different environmental
conditions on each island.
Darwin’s work
• Darwin’s theory of evolution by natural
selection has three main parts:
• 1. Species can produce more offspring
than will survive to reproduce.
• 2. Individuals within a population differ
due to random mating, recombination, and
mutation, among other sources (Darwin did
not know the genetic basis of inheritance,
but he could see that offspring resembled
parents strongly enough that it was
possible to breed for particular types of
offspring.)
Darwin’s theory of evolution by natural
selection has three main parts:
• 3. Variation among individuals results
in some individuals that are more
suited to survive in a particular
environment than are other
individuals.
Question
• What is the difference between
artificial selection and natural
selection.
Darwin was not alone in his ideas.
• Charles Lyell developed the
idea of uniformitarianism.
• That the forces of wind, rain,
rivers, volcanoes, and
geological uplift shape the
earth today.
• DO YOU AGREE?
Adaptation
• When do animals adapt?
• Name some examples of adaptation?
Types of Evolution
• Two main types
• 1. microevolution
• 2. macroevolution
1. microevolution
• A change in frequency of
alleles in populations over
time.
• Example: the possibility of
this in jaguars and leopards.
Turn to page 58 in your book.
Notice the similarities.
2. macroevolution
• Large scale changes that result in
extinction or the formation of a new
species.
• These are difficult to observe.
• Evidence however is always left
behind.
What areas study this evidence?
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1. Biogeography
2. Paleontology
3. analogy
4. homology
5. comparative anatomy
6. phylogeny
Break into groups for quick mini
presentations.
Evolution What do you
think?