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Biology Chapter One. Earth and Diversity. Yellowstone National Park – pools of hot water as acidic as vinegar….full of life. . Thermophiles. Exist best between 120F and 158 F. Deep Oceanic depths.
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Earth and Diversity • Yellowstone National Park – pools of hot water as acidic as vinegar….full of life.
Thermophiles Exist best between 120F and 158 F
Deep Oceanic depths • 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, singled-celled organisms that are thought to resemble some of the world's earliest life forms.
Deep Oceanic depths • 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.
Deep Oceanic depths • 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.
Ice • 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.
The Point • 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.
So how many planets? • 14 November 2006Since 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.
Estimate • 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 • Unfortunately, that’s 2.6 trillion less than our current national debt. The estimated population of the United States is 306,572,281so each citizen's share of this debt is $37,857.87.
Back to Earth • 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.
Species • 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.
Species • 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.
Biology • The scientific study of all forms of life; or all organisms. • An organism is any individual living thing.
Cells • 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.
Energy • 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.
Respond • 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.
Reproduction and Development • 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.
System An organized group of related parts that interact to form a whole. • An ecosystem is a physical environment with different species that interact with one another and with nonliving things.
Homeostasis • 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.
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.
Evolution • So what EXACTLY is evolution? • What is so controversial? • What stirs up the masses and angers people?
Revolution in Evolution • 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.
A brief History • 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.
Remember these Names? • Richard Owen • Adam Sedgwick • John Stevens Henslow • Samuel Wilberforce • These are the men who strongly opposed Darwin in the 1600’s.
Evolution Now • 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.
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.[
From the Vatican • 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....
Centers FOR Evolution • 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.
Basic Ideas in Evolution • 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.
Proof of Adaptation • 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 maltose-based 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.
Scientific Thinking and Processes • 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.
Testing the Hypothesis • 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
Testing a Hypothesis • 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.
The Experiment • 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.
The Experiment • 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.
A Theory • 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.
Tools of the Trade • 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.
Electron Microscopes 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.
SEM’s • 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.
TEM’s • 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.
X Rays • 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.
MRI’s • Magnetic Resonance Imaging is used to get a complete view or cross section of a tissue.
