Download Slide 1

#1. List two similarities between trilobite’s A, B, C, D.
#2. List two differences between trilobite’s A, B, C, D.
#3. Explain a reason why trilobites A and D are
different, yet similar.
500 mya
450 mya
Chevalier de Lamarck
 French biologist and botanist, (1744-1829)
 Research led him to conclude that plants and animals
change over time to adapt to their environment. These
changes in organisms are passed on to offspring.
Charles Darwin
 British naturalist, (1809-1882)
 Naturalist aboard the H.M.S. Beagle from 1831 to 1836
 Studied the life and fossils found on the Galapagos Islands
Best known for studying finches.
Darwin

He was influenced by Lamarck’s research
 Based on his research in the Galapagos he suggested
the following theories:
(1) that evolution had occurred
(2) that most evolutionary change was gradual, requiring
thousands or millions of years
(3) that the primary mechanism for evolution was a process
called natural selection
(4) that the millions of species present on Earth today arose
from a single original life form through a branching
process called speciation, by which one species
can give rise to two or more species (Coyne, 2007).
Natural selection (commonly referred to as the
survival of the fittest) The theory that the organisms that survive to
produce offspring have inherited the most favorable
traits for survival in a particular environment.
 Led to the development of the theory of evolution.
Natural Selection
Brought about by:
Competition
Predation
Climate changes
Immigration/Emigration
What physical features makes
these organisms suited (or not
suited) for this environment?
What physical features makes
these organisms suited (or not
suited) for this environment?
Evolution- Theory; a process that
produces new life forms over time.
Gradualism- evolutionary processes take place
over millions of years in gradual and continuous
changes between organisms (millions to hundreds
of millions of years).
 Commonly accepted theory.
 Supported by Darwin.
 Fossil record is incomplete, it does not represent every evolutionary
change that took place.
Punctuated Equilibrium- evolutionary
processes occur in rapid, irregular spurts
(thousands to a few million years).
 Suggested by Stephen Gould (1941-2002).
 Fossil record has examples of rapid changes between species.
Creationism- is a set of beliefs
based on the idea that a Supreme
Being brought into existence Earth
and all its life through a direct act of
creation.
Why is evolution not a proven
theory or law?
• Gaps in the fossil record.