Web Activities
UNIT 4: EVOLUTION
Chapter 13 - The Evolutionary History of Life
Did You Know?
p. 590
The Panspermia Theory
"What conditions on Mars might have permitted or fostered abiogenesis?"
Panspermia
Theories
Panspermia Theories provides references relating to the main branches
of thought relating to the origins of life in outer space. Summaries
of papers that were published in the magazine, Nature, can
be viewed online at www.nature.com, by registering a username and
password, free of charge.
Cosmic
Ancestry
Cosmic Ancestry is a powerhouse collection of information on the theory
of panspermia. Articles, essays, interviews and speeches are interspersed
with commentary and links. One section is dedicated to the evidence
for the theory, but keep in mind that some of the writing on the site
is not scientific in nature.
Panspermia:
Seeds from Space
Panspermia: Seeds from Space is a well-written article in California
Wild magazine that details the history of, and evidence for,
the idea that life on Earth originated in space.
Life
on Mars?
Life on Mars? asks this 1996 press release from NASA. The article
briefly outlines the idea that life that once existed on Mars may
have been the source of life on Earth. There are multitudes of further
links to explore by clicking on the highlighted text in the article,
including a whole list about the evidence of life on Mars.
Life
on Mars
The Life on Mars section of the NASA Web site provides a broad range
of in-depth information on the conditions on Mars, past and present,
as far as is known. There is plenty of discussion surrounding the
question of life having existed on Mars.
p. 590
Section 13.1 questions
7. Some scientists have different perspectives on the earliest
evolutionary history on Earth. In print and electronic resources, find
out more about their research, evidence, reasoning, and differing interpretations
of experimental results.
Origins
of Life Links
This list of Origins of Life Links, from a NASA Web site, provides
access to credible sources with info on different scientific theories
and experiments.
Origins
of Life
Origins of Life is an excellent Web site from NASA with good coverage
of the basic theories and ideas surrounding one of science's biggest
questions.
How
Close are Scientists to Knowing the Origin of Life on Earth?
A chemist answers the question How Close are Scientists to Knowing
the Origin of Life on Earth?, as posed by a Scientific American
reader. One plausible route to life - RNA from clay - is discussed.
Are
We Alien Life?
Are We Alien Life? asks this Scientific American article
addressing research published in 2001 that suggests that the conditions
for the creation of life are all over space in interstellar clouds.
p. 599
Explore an Issue - Take a Stand: The Human Meteorite?
Statement: Because extinction is a natural process of evolution, and
because the extinction of one species can benefit others, people should
not be concerned about the loss of species even as a result of human
activity.
- Research the issue, searching for information in print and
electronic resources.
- You might want to consider how the current pace of extinction
compares with extinction rates in nature. Find out what tropical and
conservation biologists, such as E.O. Wilson, think about this issue.
What impact might the preservation of genomes of endangered species
have? What species are likely to benefit? How long might it take new
species to fill the ecological gap left by the species that became
extinct?
History
of Extinction
A brief History of Extinction is given on this Web page from the
environmental group, the World Resources Institute. The variation
in extinction rates through geologic time is accompanied by an historical
discussion of the human impact on biodiversity.
Species
Extinction
Species Extinction, a Web page from the Rainforest Action Network,
outlines the organizations opinions about just how much humans have
accelerated extinction and what can be done about it. The references
at the bottom of the page contain some more useful Web links.
World's
Biodiversity Becoming Extinct
From ScienceDaily.com online magazine comes this 1999 story
with the headline, World's Biodiversity Becoming Extinct. The article
reports on data that estimates that human activity has boosted the
current extinction rate to levels that rival those of the periodic
mass extinctions of foregone eras.
E.O.
Wilson on Extinction
E.O. Wilson on Extinction is an excellent, balanced essay written
by the prominent scientist and environmentalist. The known impact
of humanity on biodiversity is discussed in common sense terms,
and realistic scenarios for the future - both positive and negative
- are outlined.
p. 601
Section 13.2 questions
4. The ability of ribozymes to recognize and cut specific RNA
molecules makes them exciting candidates for human therapy. For example,
one target for ribozymes might be the mRNA that encodes vascular endothelial
growth factor (VEGF). VEGF stimulates the production of blood vessels
necessary for the rapid growth of cancer tumours. A ribozyme that destroys
this mRNA might prove valuable in the treatment of many cancers. Find
out what other exciting research is underway regarding potential applications
of ribozymes. Report your findings to the class.
The
Ribozyme Web Page
The Ribozyme Web Page lives up to its subtitle, "A comprehensive
collection of information and links on all aspects of ribozymes",
with the 'Science and Research' section being of particular relevance.
Sirna
Therapeutics
Sirna Therapeutics is a company that develops and sells ribozymes
for therapeutic purposes. Their Web site provides background on the
theory behind the use of ribozymes, as well as outlining various applications
and new technology developments.
p. 617
Did You Know?
"Lucy"
"Lucy" and other early human ancestral fossils can be viewed
online.
Human
Origins
Human Origins is a Web site created by students, for students. It
has some excellent descriptions of early hominids, as well as quick
facts, and illustrations and photos of some of the key species that
have been discovered, including Lucy's bones.
Archeology
Info
From Archeology Info comes this great looking Web site with the 'hall
of skulls', featuring photos of the fossil heads of a large number
of hominids. The 'species overview' provides additional photos, info,
and great illustrations of the known hominids.
Human
Evolution
Human Evolution in 3-D! The University of California, Santa Barbara
has created 5, 3-D fossil skulls using Shockwave, that the user can
rotate at will, and compare to 3-D skulls of modern apes.
p. 621
Try This Activity: Were Neanderthals Homo sapiens?
Compare an actual Neanderthal mtDNA sequence to that of modern
humans.
a. How does the mitochondrial DNA of humans compare with
chimpanzees?
b. How many base-pair differences are typically found between the
mtDNA of any two distantly related people?
c. How many base pairs could be sequenced in the Neanderthal mtDNA?
d. How many differences were detected between the Neanderthal sequence
and that of a modern human?
e. Does this DNA evidence suggest that Neanderthal are archaic members
of the modern human species or members of a different species? Explain.
Mitochondrial
Control Region
Mitochondrial Control Region is a fantastic genetic site, all about
mtDNA. The 'Theory' section explains the origins and function of mtDNA,
its role in disease, and its applicability to science. The 'Media'
section contains an animated essay that tells the story of Solving
the Neanderthal Mystery. Clicking on the arrow at the bottom
of the first screen in the 'Exercises' section leads to step-by-step
instructions on how to access, compare, and interpret real sequence
data contained within the site.
Fossil
Hominids: Mitochondrial DNA
Fossil Hominids: Mitochondrial DNA is a balanced, matter-of-fact essay
on the mtDNA research that has been done on fossil hominids, particularly
Neanderthals. Comparisons with humans and chimps are made, and the
implications of the results discussed in simple terms. A list of links,
mainly to news reports on the mtDNA research, is given at the bottom
of the page.
p. 622
Section 13.5 questions
12. As the rapid pace of fossil discoveries continues, new
members are being added to the human family tree. In 2001, paleontologists
reported the discovery of what they believed to be a new species of
hominid. The species, named Kenyanthropus platyops, is 3.5
million years old. In addition, evidence suggests that Homo rudolfensis
may belong in the same genus as Kenyathropus. Work the
Web and construct a revised version of the hominid family tree based
on the latest reported fossil evidence.
Chronology
of Fossil Hominids
The Chronology of Fossil Hominids illustrates the known hominid species
and their speculated connections in evolutionary history. This PDF
document is a part of a course at Indiana University.
Early
Human Phylogeny
Early Human Phylogeny is a flashy, graphical illustration of a hominid
evolutionary tree, showing the relationships between species, based
on current knowledge. This is part of an excellent human evolution
site by the Smithsonian Institute.
Recent
Human Evolution News
Recent Human Evolution News can be found on the home page of the Leakey
Foundation Web site. Current stories of recent discoveries and updated
theories are featured.
Interactive
Human Timeline
This Interactive Human Timeline, from a PBS educational Web site,
is a fun way to explore the hominid species, and the ways that they
might be evolutionarily related to each other.
New
Hominin Genus from East Africa
New Hominin Genus from East Africa is a summary of the original article
in Nature magazine that broke the 2001 news of the discovery
of Kenyanthropus. The story is posted on the Smithsonian
Human Evolution Web site.
News
and Views
The News and Views section of the Becoming Human Web site includes
numerous up-to-date articles on the latest finds and theories.
p. 627
Career - Practice
4. Conduct an online search to identify employment opportunities in
your selected career. Describe a typical day in the career you chose.
Explain what the duties are and describe some of the working conditions?
Do you work mainly indoors or outdoors? Do you work mainly with people?
What materials do you handle?
Science
Jobs
Science Jobs, from the publishers of NewScientist magazine,
is a fully searchable database of current jobs available, organized
by subject and geographical area.
The
Occupation Handbook
The Occupation Handbook features a long, indexed list of careers,
with a job description, the daily routine, and the training required
given for each entry. This site is administered by the U.S. Department
of Labor.
Careers
in and out of Science
Careers in and out of Science provides a massive number of links for
students wishing to work in science. Scroll down to find numerous
job sites featuring science jobs both in and out of academia.
Lab Exercise 13.5.1 Comparing Homonoid Chromosomes
p. 631
Part II: Matching Karyograms
5. Obtain from your teacher a set of human karyograms and a set
of chimpanzee karyograms. Note that, as each pair of homologous chromosomes
has an identical banding pattern, it is only necessary to compare the
22 autosomal and two sex chromosomes. Record the differences in the
number of chromosomes.
Index
to Chromosome Comparison Graphics Page
The Index to Chromosome Comparison Graphics Page comes from the Web
page "Comparison of Human and Chimpanzee Chromosomes" by
Beth Kramer. This page of activities based on human evolution patterns
is maintained by the Evolution and the Nature of Science Institutes.
p. 633
Synthesis
(k) Evidence from these and other comparisons indicates that, at some
point in the last 7 million years a human ancestor was born with a fused
chromosome 2. Of course such an individual could not pass on this new
trait without reproductive success. How could such an individual pass
on its fused chromosome, when all potential mates had a different number
of chromosomes?
Comparison
of the Human and Great Ape Chromosomes as Evidence for Common Ancestry
Comparison of the Human and Great Ape Chromosomes as Evidence for
Common Ancestry discusses how differences and similarities in the
ape/human chromosomes can be interpreted in light of evolution. The
fusion of chromosome 2 is explained, and some 'creationist' objections
to the evolutionary evidence are addressed.
