|
What traits did Linnaeus consider when classifying organisms? |
biologically important characteristics (important features and biologically differences) |
|
What problems are faced by taxonomists who rely on body-structure comparisons? |
It was difficult to decide which similarities and differences are most important. |
|
Darwin’s theory of evolution changed the way biologists thought about __________. |
Classification |
|
How do biologists now group organisms into categories? |
They group them into categories that represent lines of evolutionary descent, not just physical similarities |
|
evolutionary classification: |
The strategy of grouping organisms together based on their evolutionary history |
|
facts about Cladistic Analysis |
–It considers only traits that are evolutionary innovations –It is a method of evolutionary classification. |
|
derived characters: |
Characteristics that appear in recent parts of a lineage, but not in older members |
|
cladogram: |
A diagram that shows evolutionary relationships among a group of organisms |
|
Derived characters are used to construct a __________. |
cladagram |
|
All organisms have ________ or RNA |
DNA |
|
How do similarities in genes show humans and yeast share a common ancestry? |
both humans and yeasts have a gene that codes for a myosin protein This similarity at the molecular level indicates a shared common ancestry |
|
molecular clock: |
A model that uses DNA comparisons to estimate the length of time that two species have been evolving dependently. |
|
A molecular clock relies on the repeating process of ______. |
Mutation. |
|
Why are only neutral mutations useful for molecular clocks? |
Neutral mutations accumulate in the DNA of different species at about the same rate because they are unaffected by natural selection. |
|
The degree of dissimilarity in DNA sequences is an indication of how long ago two species shared a ______ _________. |
common ancestor |
|
Why are there many molecular clocks in a genome instead of just one? |
Some genes accumulate mutations faster than others |
|
cladistics |
phylogenetic tree |
|
Linnaeus was a ____. |
Christian |
Share This
Flashcard
