Transcript File

April 25, 2016
Bell Work:
• What is natural selection?
Objective:
The student will be able to…
1. Describe the biological basis of
evolution.
Today in History
• 1859 Ground was broken for the Suez
Canal.
• 1901 New York became the first state to
require automobile license plates.
The Theory of Evolution
Formation of New Species
• Species: a group of organism that are closely related and
naturally mate to produce fertile offspring; also the level of
classification below genus and above subspecies.
• Species formation occurs in stages
• Divergence is the accumulation of differences between
groups.
• Divergence leads to speciation, which is the process to form
a new species.
• Subspecies are populations of the same species that differ
genetically because of adaptations of to different living
environments.
Formation of New Species
• Reproductive isolation is the condition in
which two populations of the same species
do not breed with one another because of
geographic separation, a difference in
mating periods, or other barriers to
reproduction.
• Example: squirrels around the Grand
Canyon
Tempo of Evolution
• Gradualism is the model of evolution in
which gradual change over a long period
of time leads to species formation.
• Punctuated equilibrium is the model of
evolution in which periods of rapid
change in species are separated by
periods of little or no change.
Active Reading
Natural Selection Worksheet
Ticket Out
• What are the two models of evolution?