| A | B |
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| What is phylogeny? | It's the study of evolutionary relationships among organisms. |
| What does evolutionary classification teach? | Living species have evolved from earlier species. (see example of barnacles and crabs on pg. 452). |
| What is cladistic analysis? | It is a method of classification that identifies and considers only those characteristics of organisms that are evolutionary innovations, the new characteristics that arise as lineages evolve over time. |
| What is a cladogram? | It's a diagram that shows the evolutionary relationships among a group of organisms; it's based on shared derived characteristics. (see example pg. 458) It's a type of evolutionary tree (like our family trees!). |
| How are similarities in DNA used to help classify organisms? | By comparing the DNA of different organisms, scientists can trace the history of genes over millions of years. |
| How does myosin tie the ancestry of humans and yeasts? | Myocin is a protein found in our muscles; in yeast, it helps internal cell parts move. It's one example of similarities at the molecular level--an indication that humans and yeasts share a common ancestry. |
| Besides DNA evidence showing similarities between organisms, what other purpose does this DNA evidence serve? | It helps show the evolutionary relationships of species and how species have changed. (ex. pg. 454) |
| Which 2 are more closely related: the American vulture, the African vulture, the stork? | The DNA of the American vulture and the stork are more closely related, showing they share a more common ancestry than either of the 2 birds with the African vulture. |
| What is a moleular clock? | It's a model that uses DNA comparisons to estimate the length of time that 2 species have been evolving independently. It relies on a repeating process to mark time--namely mutation. |
| If 2 organisms are dissimilar, how does a molecular clock model help scientists? | The degree of dissimilarity is an indication of how long ago the 2 species shared a common ancestor. |
| Why is the use of molecular clocks so complex? | There are more than one molecular clocks in a genome. This is because some genes accumulate mutations faster than do others (see 455). |
