Summary BIO 141 EXAM 1 Study Guide

Study Guide for Exam #1 Biology 141 Cafferty


 Evolution by Natural Selection
o Describe the transition in philosophy of considering variation of traits within a species as
being unimportant to being the key to understanding the nature of species
 Plato: claimed variation was unimportant
 Because every organism must deviate from the perfect type, and these
types are unchanging
 TYPOLOGICAL
 Aristotle: “The great chain of being” with organization from complexity and size
 TYPOLOGICAL
 Lamarck: claimed species change with their environment and pass it on to
offspring
 Ex. Giraffes
o Describe how Darwin and Wallace came up with their theory
 Darwin
 Galapagos Mockingbirds
o Different islands had slightly different birds, yet they were like a
species that he saw on the mainland
o Must have evolved
 Wallace
 Malay Archipelago
o Saw adaptations in flying frogs and birds of paradise
o Must have evolved
 Evidence for Evolution of Natural Selection
o Describe how Darwin and Wallace’s theories were different from existing theories
 Common belief in their time:
 Earth was young (4004 BC)
 Species were created perfect by God (they don’t vary or change)
 Darwin and Wallace’s theories
 Gradualism (species change over time)
 Multiplication of species
 Evolution as such (species change)
 Common descent
 Natural Selection (sexual selection)
o Describe the lines of evidence for the theory of evolution by natural selection
 The Earth must be OLD
 ~4.5 Billion years old
 South American Rhea
 2 species of flightless bird; different flightless birds elsewhere, but
similar in many aspects
 Common rhea and lesser rhea
o List the following 8 lines of evidence and explain how they provide evidence for
evolution by natural selection
 Biogeography
 Similar species are found in the same geographic area

, Study Guide for Exam #1 Biology 141 Cafferty


 Artificial breeding
 Descent with modification through artificial breeding
 HUMANS do this, NOT nature
 Intermediate forms
 Gradual stages between simple and complex forms
o Ex. Eyes
 Imperfections
 Octopus do not have a blind spot while humans do
 Does being more complex always mean being more perfect?
o NO
 Transitional fossils
 Intermediate forms in fossil records
 Used to be known as the missing link
o Inaccurate as these fossils are not necessarily direct
descendants of previous organisms OR direct ancestors of later
organisms
 Hierarchical Organization
 Life is organized in nested groups of organisms
o EX. Animals
 Insects
 Beetles
 butterflies
 birds
 ducks
 eagles
 Homology
 Definition
o Characteristics in different organisms have similar underlying
molecular and anatomical structures, or are based on similar
developmental processes
 Similarities
o Humerus, radius, ulna, carpals, metacarpals, phalanges
 IN
o Humans, moles, horses, dolphins, bats
 Vestigial traits
 Definition
o A useless of rudimentary version of a structure that has an
important function in other organisms, sometimes used for a
new function
 Ex. Whales
o Vestigial pelvis/femur
 Phylogenetic Trees
o Analyze phylogenetic trees
 Phylogeny: evolutionary tree