Evolution Notes I & II • Page Page 1 of 4
Evolution Notes I & II
Adaptation is any trait that is determined genetically
and enhances an
organism's fitness.
Adaptation
a. ___________________________________
b. ___________________________________
c. ___________________________________
Evolution is a
and
process. Shorter the generation time,
evolution occurs.
evolution special kind occuring in few generations (2-3 hours in
some bacteria) in a given population.
Evolution is:
a.
--- new adaptation do not arise out of thin air, they arise
from something already present -b.
changes --- cannot tell what will happen next -Rapid change in terms of evolution is 10,000 years.
This equals 1/2 mm of in a rock layer, brief to a geologist.
Key People
James Hutton in 1795 rejected previous ideas and state the present is the key
to the past.
He looked at
and determined it would take a vast amount
of
to accumulate.
He advance the idea that the earth was
of years old.
Charles Lyell made Hutton's work popular and wrote book that looked at slow
gradual changes,
records and that
species and extinction were slow processes.
Charles Lyell made Hutton's work popular and wrote book that looked at slow
gradual changes,
records and that
species and
were slow processes.
Fossils
Fossils form when organisms are covered with
.
They are found in sedimentary rocks. These rocks are made when rock and soil
particles are
by water and under
Because most organisms decompose, there are
fossils
found of soft tissue organisms.
Most fossils are made out of
&
Evolution Notes I & II • Page Page 2 of 4
Age of fossils are determined by:
a)
or
b)
requires presence of carbon
Both use
to determine age of object.
Carbon 14 isotope has half-life of 5, 730 years.
In
years there will be half the energy left in the original C14
sample.
14
CO2 is found in all
organisms.
This method only works on items less than 20,000 years old.
Other isotopes are used to test surrounding rocks for dating older specimens.
Geologic time is divided into:
1.
(4),
2.
(11),
3.
(7 all during the Cenozoic era)
When organisms are found in the fossil record and are no longer living then they are said
to be
.
By studying the fossil record different organisms can be compared. Scientists look at
body structures.
Example:
1. whale:
2. lion:
3. human:
2. bird:
2. fish:
Some structures have no apparent use, these are called
or
. It is thought these structures were used by
the organism's
.
Besides comparing homologous structures, scientists also look at
1.
2.
a.
b.
Evolution Notes I & II • Page Page 3 of 4
c.
Old Theories
Before Lamark and then Darwin, several theories existed. Their common
factor was changes occurred on a
scale or time line.
Lamark (French)
Believed organisms changed in response to environment. He was the first
to turn the fixed scale into a
stating new species were
scale
being
of
created.
progress,
At
lower end of the scale by
the
. His
ideas appeared in his book Philosphie Zoologique (1809) . He was first to
place scale from lower life forms to man. On problem is he ignored gaps
in the scale. The theories arising from Lamark are:
1.
2.
3.
4.
characteristics (example: giraffes' necks).
Evolution Notes I & II • Page Page 4 of 4
Charles Darwin
Wrote
,
which
sold out in the first day and a total of six editions were sold during his life.
The following ideas were expressed in his book:
1. evolution has occurred
2. mechanism of evolution is
Evolution is a
. Natural selection is the
by
which evolution takes place (occurs).
Six steps to Darwin's theory of natural selection:
1.
All organisms produce more
than can actually survive.
2.
Every organism faces a
struggle to survive.
3.
The individuals of a given species
4.
The individuals that are best
.
to the environment survive.
5.
The organisms that survive
their traits on to
.
6.
The
environment.
will become better fit for the