Download Concept 15.1: The diversity of life is based on

Concept 15.1: The diversity of life is based on the origin of new species
I. What is a Species?
A. Biologist define a species as a _____________________
______________________________________________ in nature and produce fertile offspring.
B. This is referred to as the __________________________
II. From Microevolution to Macroevolution
A. Earlier we saw _______________________ refers to a change in the ______________________ in a
population.
B. Macroevolution is _____________________________
 New species evolving (_________________)
 Extinction of species
 New features of living things
C. Speciation leads to an increase _____________________
III. Reproductive barriers between species
A. Reproductive isolation is a condition that ___________
_____________________________________________. Reproductive isolation usually involves two
or more of the following, but just one is sufficient for isolation to happen
 ___________- breeding seasons occur at different times
 __________________________- different mating behaviors prevent successful mating
 _______________________- species are adapted to specific habitats in the same area and don’t
interact
 Structure- reproductive structures are _______________
 Sterility- mating may occur but offspring are _________
______________________________________________
IV. Geographic isolation and Speciation
A. When one species becomes physically separated into two populations, the separation may lead to
____________ __________________________________________. This is called
_________________________________.
B. Species can become geographically isolated from each other in two ways
1. _________________________________________ may change and separate a species
2. The species may be ________________________
_________________________________________ by other methods (stowaways on ships or
planes)
V. Adaptive Radiation
A. When _______________ species arise from one common ancestor and spread-out to and adapt to
__________________habitats this is known as
____________________________________________
B. The numerous types of finches in the Galapagos Islands are an example of adaptive radiation.
VI. Tempo or Speed of Speciation
When species diverge in spurts of __________________ ______________________, then these new
species may remain unchanged for an extremely long period in the fossil record this is known as
____________________________.
Concept 15.2: Evolution is usually a remodeling process
I. Refinement of Existing Adaptations
A. Complex structures may have evolved from a ________ ___________________ having the same
basic function
B. An example of this would be the __________________
____________________________________________
II. Adaptation of Existing Structures to New Functions
A. There are thousands of instances where existing materials or structures evolved into new
adaptations
B.
C.
_______________originated to help marine animals from predators, now it is found in land
animals and it is used to _______________________
The flippers of penguins are another example of using
____________________________________________
III. Evolution and Development
A. ______________________________ is the study of the processes of multicellular organisms as
they develop from fertilized eggs to fully formed organisms
B. Genes that control the development of an organism are of particular importance
C. Sometimes the _______________________________ of development plays a role in evolution
Concept 15.3 The fossil record provides evidence of life’s history
I. How Fossils Form
A. Soft body parts usually _________________, and hard parts like bone, teeth and shells may
become fossils
B. Fossils aren’t always bone, they can be ___________
___________________________________________
II. The Fossil Record and Geologic Time Scale
A. The ________________________________ organizes Earth’s History into four distinct ages
known as the Precambrian, Paleozoic, Mesozoic and Cenozoic Eras
B. ___________ are divided into ________________ and the ______________ are divided into
epochs
C. New eras are recognized by a ___________________
___________________________________of that time
III. Dating Fossils
A. _____________________________ measures certain radioactive isotopes to determine the ages
of rocks and fossils
B.
C.
_____________________ is the number of years it takes for 50% of the original sample to decay
The half-life is ___________________ by temperature, pressure and other environmental
conditions
IV. Continental Drift and Macroevolution
A. Landmasses on different plates change position relative to one another known as
_________________________
B. There are two major events of continental drift that had a major impact on the history of life
1. 250 million years ago all the plates moved together forming
_____________________________
2. 180 million years ago Pangea began to break up,
_______________________________________
V. Mass Extinctions
A. Earth had relatively long periods of stability broken by brief episodes of great species loss known
as ________________________________
B. Extinctions occur all the time but there have been five or six distinct periods of mass extinction
over the last 600 million years
C. After every extinction the ______________________ have a new opportunity to change
Concept 15.4 Modern taxonomy reflects evolutionary history
I. What is Taxonomy?
A. _____________________________________ involves the naming and classification of
organisms
B. The goal is to reduce confusion and organize life into larger groups or related species
II. The Linnaean System of Classification
A. Carolus Linnaeus developed a system that uses a ___ _________________________________for
each species and a hierarchy of species into broader groups
B. The two part name is ___________________ which means the first name is the genus and the
second name is the species
III. Classification and Evolution
A. A diagram that reflects evolutionary relationships has a branching pattern called a
_______________________
B.
C.
________________________________________ is a process in which unrelated species from
similar environments have adaptations that seem similar
Similar adaptations that result from convergent evolution are called
____________________________
IV. Molecular Data as a Taxonomic Tool
A. The relatedness of species can be measured by _______
_____________________________________________
B. This evidence is independent of structural data
V. Cladistics
A. ________________________________ is the scientific search for ancestral relationships among
species
B.
C.
Each branch on a cladogram is called a ___________; every clade consists of an ancestral species
and all of its _________________________
________________________________ are homologous characteristics that unite the organisms
as a group
VI. Comparing Classification Schemes
A. The Kingdom is the broadest taxonomic category
B. Biologists have gone from a two-kingdom system, three-kingdom system, five-kingdom system
and now to a three ______________ system