2 Science T/F Science is a system of beliefs. Scientists rely heavily on imagination to carry out their work.3. Scientists are totally objective in their work
3 Science T/F4. The scientific method is the accepted guide for conducting research.5. Experiments are carried out to prove cause-and-effect relationships.
4 Science T/F6. All scientific ideas are discovered and tested by controlled experiments.7. A hypothesis is an educated guess.8. Scientific ideas are tentative and can be modified or disproved.
5 What is Science?It uses previous knowledge and theories to gain new knowledge and to produce new and better theories through observations of the natural world.
6 What is science? Science is a process to build understanding. Example: The earth was once believed to be flat.Do we still think this today? Why?
7 What science is NOT? Is not a system of beliefs Does not prove anything! It can only accept the best explanation at that time until it is disproved.
8 What science is NOT?Science cannot make decisions about morals, laws, literature, visual arts, music, etc.It cannot draw conclusions about things it cannot measure or manipulate.
9 Science as moral solution? Can science offer a solution to whether stem cell research is right or wrong?NO! It can offer only information gained from research and observations in order for people to make their decisions.
10 Hypothesis, Laws, and Theories Hypothesis: testable explanation based on previous observationsLaw: general statement that describes a natural phenomenaTheory: explanation of how a law works
11 Laws and TheoriesAtomic Theory explains the Law of Conservation of MassChromosomal theory of inheritance explains the Law of Heredity
13 I. Idea’s From Darwin’s Time A. Evolution is all of the changes that have transformed life over timeIn the mid 1700’s George Buffon suggested that the Earth is older than 10,000 years oldIn the early 1800’s Jean Baptiste Lamarck developed the idea of Inheritance of Acquired Characteristics
14 II. The Voyage of the Beagle A. In 1831 The HMS Beagle left England for a five year voyage around the worldB. Darwin studied the geology, plants, and animals he encountered
15 III. Darwin’s Observations A. Darwin maintained extensive journals of his observations, studies and thoughtsDarwin noticed the animals and plants he observed were uniquely South AmericanDarwin was especially intrigued by the Galapagos Islands because of their diversity
16 IV. Ideas from GeologyA. Darwin read books from Charles Lyell that proposed Earth’s features today could be explained by geological processesB. From this Darwin made two conclusions1. The Earth must be very old2. Slow and gradual processes occurring over vast amounts of time could cause tremendous change
17 V. Darwin Publishes His Theory A. Over many years after his return, Darwin developed his theory based on observations, inferences and ideasB. In 1844 Darwin wrote a 200 page essay that outlined his ideaC. In 1859 Darwin released his findings to the public in the book The Origin of Species
18 VI. Darwin’s Two Main Points A. Darwin’s first point was that the species of organisms living on Earth today descended from ancestral species, Descent with ModificationB. Darwin’s second main point was that Natural Selection is the mechanism for evolution
21 I. The Fossil RecordA. Preserved remains or markings left by organisms that lived in the past are called fossilsB. The positions of fossils in the rock strata can reveal relative ageC. The fossil record is this chronological collection of life’s remains in the rock layers
24 II. Geographic Distribution A. The differences and similarities between organisms and different parts of the world shows how species today evolved from ancestral formsB. Geographic distribution gives clues as to how modern species evolved
26 III. Similarities in Structure A. Similar structures in species sharing a common ancestor are called homologous structuresB. Vestigial structures are remnants of structures that may have had important functions in an ancestral species, but have no clear function today
28 IV. Similarities in Development A. Embryos of closely related organisms often have similar stages in developmentB. Comparing the development of organisms supports other evidence of homologous structures
30 V. Molecular BiologyThe closer two organisms DNA sequence match, the closer the relationshipDNA and protein analysis are new tools for testing hypothesis about evolutionC. There is molecular evidence that there are common genetic codes shared by all species
34 14.3 Darwin proposed natural selection as the mechanism of evolution
35 I. Darwin’s Theory of Natural Selection A. A population is a group of individuals of the same species in the same area at the same timeB. Populations in different areas become more and more different, leading to new species
36 II. Observations Lead to A Question A. There are 13 species of finches unique to the Galápagos IslandsB. They most closely resemble one finch species living on the South American mainland
37 III. More Observations Lead to an Idea A. Darwin recognized that all species tend to produce excessive numbers of offspringB. Darwin also recognized there was variation among the individuals of a population
41 IV. Artificial Selection A. Artificial selection is the selective breeding of domesticated plants and animals to produce offspring with traits that humans valueB. You see this change in Dog’s over the last 500 years
48 Pesticides- natural selection C. This illustrates two key points about natural selection1. natural selection is a “screening” of the traits available2. natural selection favors those characteristics in a varying population that fit the specific current, local environment
55 14.4 Microevolution is a change in a population’s gene pool
56 I. Populations and Their Gene Pools A population is the smallest level at which evolution can occurThe gene pool consists of all the alleles in all the individuals in a population
57 II. Changes in Gene Pools A. Natural selection is not randomB. Microevolution is a change in the frequencies of alleles from generation to generationC. The Hardy-Weinberg Equilibrium is when a populations gene frequencies are not changing, i.e. not evolving
58 Hardy-Weinberg p + q = 1 p =% of dominant allele (decimal) q = % of recessive allele (decimal)R= 70% so p = 0.7r = 30% so q = 0.3
61 III. Genetic DriftA. A change in the gene pool due to chance is called genetic driftB. The smaller the population the greater the impactC. The Bottleneck Effect is when a disaster reduces the size of a gene poolD. The Founder Effect is when a few individuals colonize a new habitat
71 14.5 Evolutionary Biology is important in health science
72 I. Natural Selection and Sickle Cell Disease A. Sickle Cell disease is a recessive disorder which affects the shape of red blood cells at a ate of 1 out of 25 people in some African populations
73 Natural Selection and Sickle Cell Disease B. Individuals with one copy of the allele are resistant to developing malariaC. Natural Selection has selected for those individuals which are resistant even with the negative affects of the sickle cell allele
76 II. Evolution of Antibiotic Resistance in Bacteria A. Antibiotics kill or slow the growth of bacteriaB. An antibiotic will kill most of the bacteria in a population but leave those which are resistant behind soon a greater percentage of the bacteria is resistant to the antibiotic
77 Antibiotic Resistance in Bacteria C. In New York City, there are strains of the bacteria which causes Tuberculosis which are resistant to all three antibiotics used to treat the diseaseD. The overuse of antibiotics is the speeding up the evolution of these strains