Transcript Biology Chapter One

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Yellowstone National Park – pools of hot water
as acidic as vinegar….full of life.
Exist best between
120F and 158 F
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At the ocean's deepest point, the water
pressure is the equivalent of having about 50
jumbo jets piled on top of you. Yet even here
life thrives, according to scientists who have
pulled a plug of dirt from the seafloor.
The sample was taken from the Challenger
Deep, which is nearly 7 miles (11 kilometers)
deep. The soil was packed with a unique
community of mostly soft-walled, singledcelled organisms that are thought to resemble
some of the world's earliest life forms.
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They're called foraminifera, single-celled
protists that construct shells. Protists are a
kingdom of celled organisms distinct from
animals, plants, and fungi. Other types of
protists include algae and slime molds.
There are an estimated 4,000 species of living
foraminifera. They inhabit a wide range of
marine environments, mostly on the ocean
bottom, though some live in the upper 300 feet
(100 meters) or so of the ocean. A few species
are found in fresh water and on land.
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However, the discovery of 432 foraminifera living in
dirt from the Challenger Deep surprised Hiroshi
Kitazato, a program director at the Japan Agency for
Marine-Earth Science and Technology (JAMSTEC) in
Yokosuka.
"We are surprised that so many [bottom dwelling]
foraminifera—in particular so [many] soft-shelled
forms—live in the Challenger Deep, because former
reports gave us the impression the world's deepest
point is scarce in any [celled organisms]," he said.
At 36,201 feet (11,034 meters) below sea level,
Challenger Deep is the lowest part of the Pacific
Ocean's Mariana Trench, located just east of the
Philippines.
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3 June 2008—A team of Penn State scientists
has discovered a new ultra-small species of
bacteria that has survived for more than
120,000 years within the ice of a Greenland
glacier at a depth of nearly two miles. The
microorganism's ability to persist in this
low-temperature, high-pressure,
reduced-oxygen, and nutrient-poor
habitat makes it particularly useful
for studying how life, in general,
can survive in a variety of extreme
environments on Earth and possibly
elsewhere in the solar system.
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Living things are found in almost every
environment on Earth, from the hottest acidic
water to the pressurized depths of the ocean;
life persists.
It would be human arrogance to assume that
we are the only form of intelligent life in the
universe knowing what we now know.
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14 November 2006
Since 1995, when Michel Mayor and Didier
Queloz of the Observatoire de Geneve,
discovered the first planet orbiting another star
like the Sun, over two hundred more extrasolar
planets have been found in more than 170 solar
systems outside our own.
AS OF MAY 2009 ASTRONOMERS HAVE
DISCOVERED 347 planets.
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If there are 3 trillion suns and each sun has an
average of 3 planets orbiting around it, that’s 9
trillion planets.
 9,000,000,000,000
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Unfortunately, that’s 2.6 trillion less than our
current national debt. The estimated
population of the United States is 306,572,281
so each citizen's share of this debt is $37,857.87.
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All living things and all places they are found
on Earth make up the biosphere.
The variety of life is called biological diversity
or biodiversity.
Greater biodiversity is found in warmer areas.
More living things are able to survive in
regions that have a consistent temperature than
areas with extreme temperature changes
through the year.
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A particular type of living thing that can
reproduce by interbreeding among themselves.
About 2 million different living species have
been identified, but biologists estimate that
tens of millions of species remain to be
discovered.
This is based on the rate of discovery and the
increasing numbers of scientists using
microscopes and studying insects.
Every year, biologists discover about 10,000
new species.
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Biologists also estimate that about 50,000
species become extinct each year. Although
our text states this, know that this figure is
estimated and very controversial.
Conservationists put forward such data as
computer models with no list of species.
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The scientific study of
all forms of life; or all
organisms.
An organism is any
individual living
thing.
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All organisms
are made up of
one or more
cells. A cell is
the basic unit of
life.
Microscopic, single-celled
organisms are the most
common forms of life on Earth.
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All organisms need a source of energy for their
life processes.
Energy is the ability to cause a change or to do
work.
Living things use chemical energy.
In all organisms, energy is important for
metabolism, or all of the chemical processes
that build up or break down materials.
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All organisms must respond to their
environment to survive. Light, temperature,
and pressure are just a few of the physical
factors, called stimuli, to which organisms
must respond.
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Members of a species must have the ability to
produce new individuals. When organisms
reproduce, they pass their genetic material to
their offspring.
In all organisms, the genetic material is in a
molecule called DNA
The instructions for growth and development
in organisms are carried by both DNA and
RNA.
An organized group
of related parts that
interact to form
a whole.
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An ecosystem is a physical environment with
different species that interact with one another
and with nonliving things.
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The maintenance of constant internal
conditions in an organism. Homeostasis is
important because cells function best within a
limited range of conditions.
It is usually maintained through a process
known as negative feedback.
In negative feedback, a change in a system
causes a response that tends to return that
system to its original state.
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So what scientific theory explains the unity and
diversity of life?
Evolution
That bad scientific term that no one really
wants to discuss because of the controversy
surrounding it. The problem, is that the battle
is over. Evolution is true. Thousands of
experiments support it and nothing has ever
been found to dispute it.
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So what EXACTLY is evolution?
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What is so controversial?
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What stirs up the masses and angers people?
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Evolution is the change in
living things over time.
It is the change in the
genetic makeup of a
subgroup, or population of
a species.
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Aristotle began classifying and organizing
animals.
Linnaeus developed a system of taxonomy.
James Hutton wrote his groundbreaking book
explaining a history of geology.
Charles Darwin traveled for five years on the
HMS Beagle collecting specimens from around
the world.
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Richard Owen
Adam Sedgwick
John Stevens Henslow
Samuel Wilberforce
These are the men who strongly opposed
Darwin in the 1600’s.
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So where does the theory stand?
After more than 150 years, churches are just
now getting to where they can discuss
evolution and debate the issues.
The Roman Catholic Church finally forgave
Galileo in 1981!!!!!!!!! For more than 300
years, they stuck with the earth centered view
of the universe.
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The position of the Catholic Church on the theory
of evolution has moved over the 150 years since
the publication of Charles Darwin's Origin of
Species in 1859 from a long period with no
authoritative pronouncement from the Vatican, to
a statement of neutrality in the 1950s, and then to
more explicit acceptance in recent years.
Today[update], the Church's official position remains
a focus of controversy and is fairly non-specific,
stating only that faith and scientific findings
regarding human evolution are not in conflict,
though humans are regarded as a "special
creation", and that the existence of God is required
to explain the spiritual component of human
origins. This view falls into the spectrum of
viewpoints that are grouped under the concept of
theistic evolution.[
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Faith and science: "...methodical research in all branches of
knowledge, provided it is carried out in a truly scientific manner
and does not override moral laws, can never conflict with the
faith, because the things of the world and the things of faith derive
from the same God. The humble and persevering investigator of
the secrets of nature is being led, as it were, by the hand of God in
spite of himself, for it is God, the conserver of all things, who
made them what they are." (Vatican II GS 36:1) 283. The question
about the origins of the world and of man has been the object of
many scientific studies which have splendidly enriched our
knowledge of the age and dimensions of the cosmos, the
development of life-forms and the appearance of man. These
discoveries invite us to even greater admiration for the greatness
of the Creator, prompting us to give him thanks for all his works
and for the understanding and wisdom he gives to scholars and
researchers.... 284. The great interest accorded to these studies is
strongly stimulated by a question of another order, which goes
beyond the proper domain of the natural sciences. It is not only a
question of knowing when and how the universe arose physically,
or when man appeared, but rather of discovering the meaning of
such an origin....
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The "Faith Movement" was founded by
Catholic Fr. Edward Holloway in Surrey,
England[43] and "argues from Evolution as a
fact, that the whole process would be
impossible without the existence of the
Supreme Mind we call God."
Unitarian Universalists
Few Baptist churches openly support
evolution, but individuals within the church
are widespread.
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In natural selection, a genetic, or inherited, trait
helps some individuals of a species survive and
reproduce more successfully than other
individuals in a particular environment.
An inherited trait that gives an advantage to
individual organisms and is passed on to
future generations is an adaptation.
Evolutionary adaptations are changes in a
species that occur over many generations due
to environmental pressures, not through
choices made by the organisms.
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Experimental results: The first steps of speciation have been
produced in several laboratory experiments involving
"geographic" isolation. For example, Diane Dodd examined the
effects of geographic isolation and selection on fruit flies. She
took fruit flies from a single population and divided them into
separate populations living in different cages to simulate
geographic isolation. Half of the populations lived on maltosebased food, and the other populations lived on starch-based
foods. After many generations, the flies were tested to see which
flies they preferred to mate with. Dodd found that some
reproductive isolation had occurred as a result of the geographic
isolation and selection for different food sources in the two
environments: "maltose flies" preferred other "maltose flies," and
"starch flies" preferred other "starch flies." Although, we can't be
sure, these preference differences probably existed because
selection for using different food sources also affected certain
genes involved in reproductive behavior. This is the sort of result
we'd expect, if allopatric speciation were a typical mode of
speciation.
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All scientific inquiry begins with careful and
systematic observations.
During an observation, we use our senses to
describe some aspect of the world around us.
Data – qualitative or quantitative information
about the world or an observation
A hypothesis is a proposed answer for a
scientific question. It has not yet necessarily
been tested.
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It is only by REPEATING tests that scientists
can be more certain that their results are not
mistaken due to chance.
Why test? Biological systems are variable.
It is only by repeating tests that scientists can
take this variability into account.
After scientists collect data, they use statistics
to mathematically analyze whether a
hypothesis is supported. There are two
possible outcomes for statistical analysis.
Nonsignificant
Statistically significant
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Nonsignificant – the data show no effect, or an
effect is so small that the results could have
happened by chance.
Statistically significant – the data show an
effect that is likely not due to chance.
ONLY after this review process is complete are
research results accepted.
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In experiments, scientists study factors called
independent and dependent variables to find
cause and effect relationships.
An independent variable in an experiment is a
condition that is manipulated or changed, by a
scientist.
Dependent variables are observed and
measured during an experiment; they are the
experimental data. Changes in dependent
variables depend upon the manipulation of the
independent variable.
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The conditions that do not change during an
experiment are called constants. To study the
effects of an independent variable, a scientist
uses a control group or control condition.
The independent variable is manipulated in
experimental groups or experimental
conditions.
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A proposed explanation for a wide range of
observations and experimental results that is
supported by a wide range of evidence.
Scientific hypotheses and theories may be
supported or refuted, and they are always
subject to change.
Theories can change only based on new and
reliable evidence.
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A microscope
provides an enlarged
image of an object.
Light microscopes
clearly magnify
specimens up to
about 1500 times
their actual size, and
samples are stained
to make details stand
out.
Developed in the 1950’s,
electron Microscopes use
beams of electrons Instead
of light to magnify objects.
An electron microscope can
clearly magnify a specimen
more than 100,000 times their
actual size. Unlike light
microscopes they cannot be
used to study living
specimens. Specimens must
be in a vacuum.
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Scanning electron
microscopes.
Scans the surface of a
specimen with a beam of
electrons.
A computer forms a 3D
image of the deflected
electrons.
The image is in black and
white and colorized by the
computer artificially.
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Transmission Electron Microscope
Transmits electrons through a thin slice of a
specimen.
Makes a 2D image similar to that of a light
microscope but with much higher
magnification.
Also given enhanced color by computer.
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X Rays are widely used in the medical field.
They are excellent for imaging bones because
the x-rays are absorbed by bones and teeth.
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Magnetic Resonance Imaging is used to get a
complete view or cross section of a tissue.