KEY TERMS
Carolus Linneaus artificial classification schemes natural classification schemes systematics taxonomy phylogeny heirarchy taxon (pl. taxa)
Kingdom
Phylum (Division)
Species
Latinization binomial nomenclature anology homology
Monera
Protista
Fungi
Plantae
Animalia
Class
Order
Family autotroph heterotroph unicellular
Genus
WORD ROOTS multicellular analog – = proportion ( analogy : similarity due to convergence) bi = two; nom = name ( binomial : a two-part latinized name of a species) clado = branch ( cladogram : a dichotomous phylogenetic tree that branches repeatedly) homo = like, resembling ( homology : similiarity in characteristics resulting from a shared ancestry)
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mono - = one ( monophyletic : pertaining to a taxon derived from a single ancestral species that gave rise to no species in any other taxa) parsi = few ( principle of parsimony : the premise that a theory about nature should be the simplest explanation that is consistent with the facts) phylo = tribe; - geny = origin ( phylogeny : the evolution history of a taxon)
QUESTIONS
1. What types of organisms are most likely to appear in the fossil record?
2. a. A fossil has one-eighth of the atmospheric ratio of C -14 to C -12.
Estimate the age of this fossil. b. Potassium – 40 has a half-life of 1.3 billion years. If an organism had i mg of potassium
– 40 when it died and its fossil now has 0.25 mg, how old is this fossil?
3. Marsupials evolved in what is now North America, yet their greatest diversity is found in Australia. How can you account for this biogeographical distribution?
4. Why do extensive adaptive radiations often follow mass extinctions?
5. What two complications may make it difficult to determine phylogenetic relationships based on similarities between species?
6. According to the principle of parsimony, the evolution of the fourchambered heart should place birds and mammals in the same clade.
Why does the most accepted evolutionary tree show them as separate branches from the reptilian line?
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7. The geologic time scale divides the history of life on Earth into four eras, delineated by major changes recorded in the fossil record. List these four eras and briefly describe some factors that may have contributed to the transitions between eras. (HINT: Consider continental drift, mass extinctions, and adaptive radiations.)
8. Base deletions have changed the lengths and alignments of these two homologous regions of DNA. Determine the best possible fit between these two DNA sequences. How many deletions and base changes occurred in these DNA segments?
A C G T G C A C G
A G T G A G G
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