Evolution Notes: Name_______________________________________Hr________________
Darwin Notes: 1809-1882
English Biologist: Famous Book, “The Origin of Species”
HMS _____________
How many years?? ___________
Naturalist
Galapagos Islands
Natural Selection: Organisms best adapted to their environment tend to survive and transmit their genetic characteristics more so than those less adapted.
Lamark 1744-1829
Aquired traits were passed on to offspring
Baby giraffes do not get longer necks because their parents stretched a lot.
Today’s Species are related to extinct species
-Fossils show change through time
Related species have unique adaptations – Darwin’s Finches have beaks adapted for soecific environments and specific tasks.
“The Origin of Species”
Theory of how new types of living things (species) arise in different places- how diversity arises
Four Key Components of Natural Selection
Variation, Competition, Fitness, Adaptation
Variation
Individual members of a population within a species have _________________ differences.
These individual differences or traits are ___________ _____ to new _________________.
Competition
Resources are _________. (Food, shelter)
Many more individuals are produced than can survive and _____________.
Populations grows to a _______________.

Indivduals must _______________ for limited resources.
Fitness
Some individuals have _______ (physical or behavioral) that make them better at surviving and _________________.
“Survival _____ ______ ____________”
______________ in linked to the _________________. What may be advantageous in one environment may not be in another.
Adaptation
Increasing _____________ of individuals in succeeding ___________ have the beneficial traits. –Those with an advantageous trait overpopulate and replace those that are less
________.
Results- New population all with the trait and __________ to their environment.
What did Darwin observe?
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What IS Natural Selection?
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Who would have likely said the following? Big D or Wrongo Lamark?
A rabbit is exceptionally good at hopping. So are her offspring. _____________
An ape uses a stick to acquire termites to eat. She teaches her offspring to do this as well.________
A Butterfly flies an exceptionally long distance. Her offspring have larger wings to make the longer flight easier. __________
In a polluted area, a moth has dark wings. Her offspring has dark wings. ________
A rat suffers an accident and loses a tail. Her offspring have shorter tails. _________

Fossils-
 Fossils are traces of things that happened _________ ____________.
 ____ and ________ can become fossils
 We have only discovered a small number of the plants and animals from the past
 Fossils are not the original, only a copy
Plants
 The most famous example of fossilized plants is ___________ ___________.
 _____, tree leaves, and other ______ have been found, too
Animals
 The most famous fossils are of __________
 There are also fossils of ____ __________ and ____________
 Sometimes many fossils are found in one place because of a ______, ___________, or other disaster
How Fossils are ___________
 Fossils are often found by ___________
 ______________ and geologists use clues in the rocks to find good places to hunt for fossils
 Excavating fossils is hard work, and must be done carefully
How are Fossils Made?
 A fossil is made when a _______ or ________ is covered quickly with mud or ash
 The organism ’ s tissues are replaced over a long period of time with _________ from the soil it was buried in
 Fossils can be ________ by the layer of rock they were found in, or by radiocarbon dating
____________ to the past
 Many fossils give us an idea of what life was like long ago
 Plants give clues about the _____ of animals
 _______ give clues about the availability of plants and the ______ when they lived
 Many clues fit together to make a more complete picture of what the world was like long ago

Natural Selection
Thinking Question:
• Some evidence exists that over several centuries, the number of people born with small wisdom teeth or no wisdom teeth has increased. Using your best understanding of Natural Selection, explain how selection could cause this.
___________________________________________________________________________
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Pt.2._______________________________________________________________________
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• Darwin spent nearly 20 years analyzing evidence as he developed his ideas. He drew on:
• His own field work during his voyage on board the Beagle.
• His work in classifying barnacles, beetles, and other organisms.
•
In addition, Darwin drew on evidence from:
•
________
•
_________ ______________
•
______________ _________________________
Fossils
• The fossil record shows that:
• Things existed in the past that no longer _____ today and
• Things exist today that did not exist in the past.
• The fossil record is a record of ________ in the composition of the biosphere over time.
Fossils are ______
• Most organisms are eaten or decay after death.
• Fossils only ______ in places where there is little _________: lake bottoms, deep oceans, etc.

• We have little fossil record of _______ organisms and _________ communities.
Some Fossils show Transition
• Because fossils are rare, and change can be rapid, there are few “ ______
______ ” in the fossil record.
• However, some fossil sequences of marine organisms do show good
________ of transition from one form to another.
Comparative Anatomy
• Darwin looked at and described:
• ________ structures
• __________structures
• ____________ structures
Homologous Structures
• Homologous structures are those that are _______ between _______ organisms, but are slightly altered.
• In modern terms, this indicates shared ______s (similar structures), but also shows genetic __________ led to ___________ evolution (modifications of those structures.
Analagous Structures
• Analogous structures are similar _________ to the same environmental challenges seen in unrelated species living in similar environments.
• In modern terms, analogous structures represent _________ evolution.
Rather than shared genes, the organisms are under similar ____________
____________.
Vestigial Structures
• Vestigial structures are those that were well-developed in an ancestor but are much reduced in a descendant.
• Vestigial structures show that different selection pressures shape organisms differently.
Comparative Embryology
• Like homology, embryology reveals shared traits between species, demonstrating ________ genes.
• As embryos _________, newer genes may shape the same structures into different parts: gill arches in fish become gills, but in mammals become parts of the face, jaw, and inner ear.
Molecular Comparisons

• Shared traits give us some _______ into shared genes. Today ’ s technology allows us to analyze genes directly.
• Because small ____________ accumulate in populations over time, more genetic differences between two different groups of organisms indicates more time since they separated from one another.
Variation Exists
• All populations _____ as the result of the accumulation of small, _______
__________ over many generations.
Inheritance of Traits
• __________ traits (those coded for by genes) are passed ___________to the offspring from the parents through genetic information.
Differential Survival
• More offspring are born than can ______. Many offspring die young. Those with traits best suited to the environment are more likely, though not guaranteed, to survive.
Differential Reproduction
• Some survivors ______ to reproduce. Some have traits that better insure reproduction than others.
Differential Inheritance
• Survivors that ____________ pass some of their _______on to their offspring. Those with favorable traits may pass those favorable traits on — or not.
Natural Selection in Action- Peppered Moth
Wisdom Teeth Revisited
• Now that we ’ ve gone through the process of selection, return to the paper on which you responded to the wisdom tooth question.
• Draw a line under your original response, and write a second one, using what you just learned about the process of selection: Variation, Inheritance,
Differential Survival, Differential Reproduction, Differential Inheritance.