Download DARWIN`S THEORY OF EVOLUTION Chapter 15

EVOLUTION
DARWIN’S THEORY OF
EVOLUTION
Chapter 15
Mr. V. M. Galdo
Science Department
BOOKER T. WASHINGTON S.H.S.
The Puzzle of Life’s Diversity (p. 369 – 372)
• During his travels, Charles Darwin made numerous
•
•
observations and collected evidence that led him to
propose a revolutionary hypothesis about the way life
changes over time.
Darwin noticed that the characteristics of many
animals and plants varied noticeably among the
different islands of the Galapagos in Ecuador.
Key Words: evolution, theory, fossil.
The Puzzle of Life’s Diversity
(cont. p. 369 – 372)
• Fossils vs. living organisms: Many of the
fossils that Darwin discovered resembled
living organisms but were not identical to
them.
Read and discuss: page 370, fig. 15-2.
• Habitats and shapes: Darwin observed
that the characteristics of many animals
and plants varied noticeably among the
different Galapagos Islands. Their shapes
seem to adapt to their habitat.
Read and discuss: page 371, fig. 15-3.
The Puzzle of Life’s Diversity (cont. p. 369 – 372)
The Warbler Data
• The warbler finch (top)
boasts a thin, sharp
beak best suited for
spearing insects. Ground
finches' shorter, more
robust beaks (center)
are adapted for eating
seeds found on the
ground. Those of cactus
finches (bottom) are
shaped for getting seeds
from cacti. (Harvard
Medical School and
Margaret Bowman)
The Puzzle of Life’s Diversity - Video
• VIDEO: Biomes: Islands and Evolution (Call
# NP 577.5 – ISL)
• Copy the questions that appear on the video
in the Questions section of your notebook.
• Answer the questions while you watch the
video in the notes section of your notebook
QUESTIONS & SUMMARY

Read pages 368 through 372 create your own
notes, at least a full page of notes.

Using the High School Question Task Cards
write at least 5 questions about today’s notes.

Write your summary.
Output

Copy and answer the 15-1 Section Assessment on
page 372, all questions 1 through 5.

GIZMO
http://www.explorelearning.com/index.cfm?method
=cResource.dspView&ResourceID=447&ClassID=8
02401

Lab: Finch Beak Evolution/Adaptation Demo (see
next slide)
Ideas that Shaped Darwin’s Thinking
1785 – James Hutton
Earth is shaped by geological
forces over extremely long
periods of time.
Earth is million
of years old.
1798 – Thomas Malthus
Predicts that the human population
will grow faster than the space and
food supplies needed to sustain it.
Essay on the Principle
Of Population. Limited
1809 – Jean-Baptiste Lamarck
First to propose
a mechanism explaining how
organisms change over time.
Resources.
Hypothesis of the
inheritance
of acquired traits.
It was wrong.
Ideas that Shaped Darwin’s Thinking
1831 – Charles Darwin
Sets sail on the H.M.S. Beagle.
A trip around the world that
lasts 5 years.
1833 – Charles Lyell
Explains that processes occurring
now have shaped Earth’s geological
features over long periods of time.
1858 – Alfred Wallace
Writes to Darwin speculating on
evolution by
Evidence and data
is collected.
Principles of Geology
2nd and final volume.
Earth changes.
Based
on his studies of
the distribution of plants
and animals
Ideas that Shaped
Darwin’s Thinking
1859 – Charles Darwin
publishes On the
Origin of Species
The Evolution of the Universe, Earth
and Life
• A HUGE TIMELINE OF EVOLUTION:
http://www.johnkyrk.com/evolution.html
QUESTIONS & SUMMARY

Using the High School Question Task Cards
write at least 5 questions about today’s notes.

Write your summary.
Output
1)
Lab – Moth or Butterfly Adaptation and Natural
Selection
Studying Living Organisms - Protective Coloration: A Model of Natural Selection (LAB)
Richard Filson -1995 Woodrow Wilson Biology Institute
Introduction
Natural selection operates on the principle of survival of the fittest. Fitness can be defined as the suitability of an organism
to a given environment. One might ask if one set of features favorable in one environment might prove unfavorable in
another environment.
In this experimental model, the features studied will be the adaptations of protective coloration in two very different
environments. You will act as the predator and your prey will be three types of paper squares, each with a different
color. Their environment will be either a sheet of light colored paper or a sheet of dark paper.
Procedure
Work in groups of three partners (a predator, an experimenter, and a data collector). One of you must always be the
predator while the others will supervise the experiment so as not to introduce an uncontrolled variable. The
experimenter's job is to spread out the prey * randomly for each trial making sure they are not piled up and that they
thoroughly cover the sheet of paper. The data collector will time each trial, count and record the data.
The predator's role here is to pick up as many preys (squares) as possible in 30 second trials and take them to the nest (Petri
dish). With the predator standing with his back to the hunting area, the data collector will give a signal, the predator
then quickly turns around and begins to hunt until the data collector tells him to stop (at 30 seconds). The data collector
writes down the total for each colored pray that was catch. This trial is repeated two more times and then the
environmental background will be changed to a different color. Again three trials will be made attempting to spot and
catch as many prays (squares) as possible in 30 seconds trials.
* The experiment will start with 45 preys – colored squares, 15 of each color. Once picked the prey is dead, and it is removed
from the environment. You must stop and wait for the teacher between trials.
Important Notes:
The particular predator in this problem only hunts for prey just before sunrise and just after sunset, therefore, the light in
the room will be very subdued.
After each trial, the experimenter should rearrange all paper circles on the paper to make sure the population is randomly
distributed. When all data is recorded, compute your average and report the results to your teacher.
Before starting, make a prediction.
Hypothesis / Prediction: Which square on which background will get the lowest count? Why?
Interpretations and Conclusions
In natural selection, selective pressure is the factor that reduces the frequency of a particular phenotype more than another
phenotype. In this model the phenotypes are white, red, and black. What was the selective pressure on this population?
Some circles went uncatched and thus escaped predation. Why did some escape?
Is survival equal for each phenotype? Explain why, or why not.
From results of this experiment, what can you conclude about the relative nature of fitness with respect to the environment?
Data Table (write a title for your table)
Light
Background
Trial No.
1
2
3
Team
Average
Class
Average
%
Died
%
Survived
%
Advantage
(%Survived - % died)
No. of
white
squares
No. of black
squares
Dark
Background
No. of red
squares
No. of white
squares
No. of black
squares
No. of red
squares
LAB REPORT
• Read pages 380 – 381, 397 – 398 and 400.
• Use the Lab Report Format to Write your lab
report about Natural Selection.
Darwin Presents His case (p. 378 – 386)
Darwin Presents His case (p. 378 – 386)
• In artificial selection, nature provides the variation
•
•
among different organisms, and humans select those
variations that they find useful. For example,
______________.
Over time, natural selection results in changes in the
inherited characteristics of a population. These
changes increase a species’ fitness in its
environment. For example,
__________________________.
Key Concepts: artificial selection, struggle for
existence, fitness, adaptation, survival of the fittest,
natural selection, descent with modification, common
descent, homologous structure, vestigial organ.
Darwin Presents His case (p. 378 – 386)
• Darwin argued that living
things have been evolving
on Earth for millions of
years.
• Evidence for this process
could be found in the
fossil record (fig.15-13),
the geographical
distribution of living
species (fig. 15-14),
homologous structures of
living organisms (fig. 1515), and similarities in
early development, or
embryology (fig. 15-17).
QUESTIONS & SUMMARY

Using the High School Question Task Cards
write at least 5 questions about today’s notes.

Write your summary.
Output


Read pages 373 – 377. Copy and answer the
15-2 Section Assessment on page 377, all
questions 1 through 5.
Read pages 378 - 386. Copy and answer the
15-3 Section Assessment on page 386, all
questions 1 through 4.
EVIDENCE OF EVOLUTION
EVIDENCE OF EVOLUTION
The Fossil Record (Sect 17-1, P. 416 - 422)
• The fossil record provides
evidence about the history of
life on Earth. It also shows
how different groups of
organisms, including species,
have changed over time.
• Relative dating allows
paleontologists to estimate a
fossil’s age compared with
that of other fossils.
• Vocabulary: paleontologist,
fossil record, extinct, relative
dating, index fossil.
The Fossil Record (Sect 17-1, P. 416 - 422)
•
In radioactive dating,
scientists calculate the age of
a sample based on the
amount of remaining
radioactive isotopes it contains.
What is a Half-Life?
• After the Precambrian Time,
•
the basic divisions of the
geologic time scale are eras
periods.
Vocabulary: half-life,
radioactive dating, geologic
time scale, era, period.
and
What is a Half-Life?
• Every radioactive element
•
•
•
•
has a half-life
Half-life is the time it takes
for half of its atoms to
decay.
Half-lives range from a
fraction of a second to
billions of years – 4.5
billion for uranium 238.
The longer the half-life,
the less intense the
radiation.
After 10 half-lives, an
element is usually
harmless
QUESTIONS & SUMMARY

Using the High School Question Task Cards
write at least 5 questions about today’s notes.

Write your summary.
Output


Read pages 417 – 422.
Using the vocabulary words, write a letter to a friend
explaining how fossils are use to support the theory
of evolution: paleontologist, fossil record, extinct,
relative dating, index fossil, half-life, radioactive
dating, geologic time scale, era, period.
UNDERLINE THE VOCABULARY WORDS IN
THE LETTER
Earth’s Early History
Earth’s Early History
• Earth’s early atmosphere
probably contained hydrogen
cyanide, CO2, carbon
monoxide, hydrogen sulfide,
and H2O.
• Miller and Urey’s experiments
suggested how mixtures of the
organic compounds necessary
for life could have arisen from
simpler compounds present on
a primitive Earth (proteinoids
microspheres)
Earth’s Early History
• The rise of O in the
atmosphere drove some life
forms to extinction, while
other life forms evolved new,
more efficient metabolic
pathways that used O for
respiration.
• The endosymbiotic theory
proposes that eukaryotic cells
arose from living communities
formed by prokaryotic
organisms.
• Vocabulary - proteinoid
microsphere, microfossil,
endosymbiotic theory
QUESTIONS & SUMMARY

Using the High School Question Task Cards
write at least 5 questions about today’s notes.

Write your summary.
Output


Read pages 423 – 428.
Write two or three paragraphs explaining what was
the main factor the help life develop the way we
know it? Use at least 3 key words from the notes.
UNDERLINE THE VOCABULARY WORDS IN
THE LETTER