Topic 1 - Topic 1 Classification and the Diversity of...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Topic 1: Classification and the Diversity of Life (Chapter 25) I. Background review (Biology 1020 material) A. Scientific Method 1. observations 2. scientific model explains observations makes testable predictions 3. test predictions (can confirm predictions) 4. reject, revise, or tentatively accept scientific model 5. caveats: Scientific models can only be proven false, never proven true. Correlation does not equal causation. Testable predictions cannot include the supernatural (the supernatural cannot, by definition, be tested scientifically); thus, the supernatural is outside the realm of science. The term “theory” has a very different meaning in science than in most everyday conversations. 6. terms: hypothesis – model that has not been tested or has only been tested some theory – model that has been tested extensively and is accepted by most scientists in that field law – usually a very well-established theory that explains a wide body of observations B. Theory of Evolution: The Modern Synthesis 1. Evolutionary relationships between organisms provides the theoretical framework for modern classification systems; as such, it is the major organizing principle underlying the structure of most of this course 2. In POPULATIONS, new mutations (random) and recombination of current variations (random) occurs. 3. Populations encounter EVOLUTIONARY MECHANISMS:
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
natural selection (greater reproduction by the “fittest”) genetic drift (random, greater for small populations) gene flow (genetic exchange with other populations) mutations (new changes in genetic material) 4. Evolutionary mechanisms cause MICROEVOLUTION: changes in population genotype and allele frequencies for the next generation. 5. Adding any REPRODUCTIVE ISOLATION MECHANISM allows MACROEVOLUTION (speciation). Examples of reproductive isolation mechanisms include physical separation, selective mating, and sterile offspring. 6. Speciation can be rapid (punctuated equilibrium) or gradual; relative amounts of these are debated but both appear to occur. II. Classification of organisms A. Biologists use a binomial system for classifying organisms. 1. taxonomy - the science of classifying and naming organisms. 2. Carolus Linnaeus (18 th century biologist) developed a system of classification that is the basis of what is used today binomial system: today each species’ official scientific name is made of 2 words (bi=“2” nomen=“name”) names are Latin same language used universally in biology dead language – not changing names of people can be “Latinized” for use in naming 3. species - basic unit of classification or taxonomy (more on this later) if sexual, a group of organisms that can interbreed and produce fertile offspring if asexual, grouped based on similarities (DNA sequence is best) about 1.8 million living species have been described, likely millions more
Background image of page 2
4. genus - a group of closely related species. 5.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 8

Topic 1 - Topic 1 Classification and the Diversity of...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online