Monday, March 2, 2009

Ch. 26 continued!

Hey girls, today (03-02-09) was just a continuation of chapter 26 so here are the rest of the notes! Don't forget to work on the take home due Wednesday and ch. 40 vocab due Thursday!

The likeness that result from convergent evolution are considered analogous rather than homologous
-they do not indicate relatedness, but rather similar solutions to similar problems
-molecular systematics uses DNA and other molecular data to determine evolutionary relationships
-the more alike the DNA sequences of two organisms, the more closely related they are evolutionarily

Shared characters are used to construct phylogenic trees

-a cladogram depicts patterns of shared characteristics among taxa and forms the basis of a phylogenic tree

-a clade, within a tree is defined as a group of species that includes an ancesteral species and all it's decendents

An organism's evolutionary history is documented in it's genome

-the rate of evolution of DNA sequences varies from one part of the genome to another; therefore, comparing these different sequences helps us to investigate relationships between groups of organisms that diverged a long time ago

Molecular clocks help track evolutionary time

-molecular clocks are methods used to measure the absolute time of evolutionary change based on the observation that some genes and other regions of the genome appear to evolve at constant rates

New information continues to revise our understanding of the tree of life

-taxonomy is influx

-we used to think there were two kingdoms, then five and now we have domains

-biologists have adopted a three-domain system which consists of the domains bacteria, archea, and eukarya

-this system arose from the finding that there are two distinct lineages of prokaryotes


1. Which of the following groups would contain the largest number of organisms?
a) class
b) order
c) phylum
d) family
2. The current classification system was devised by:
a) Aristotle
b) Plato
c) Linneaus
d) Darwin
3. If two organisms are in the same phylum, they must also be in the same:
a) class
b) species
c) family
d) kingdom
Answers: c, c, d

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