Topic 1- Diversity of Organisms

Question 1

nomenclature

Answer 1

a system for naming things

Question 2

taxonomy

Answer 2

the practice of naming & classifying organisms

Question 3

systematics

Answer 3

the theory (& practice) of classifying organisms based on evolutionary history

Question 4

order of linnean system of classification (least related to most related)

Answer 4

kingdom 
phylum 
class 
order 
family 
genus 
species 
(katy perry comes over for grape soda)

Question 5

what is an example of subspecies

Answer 5

Dogs and coyotes. They are the same species, but different subspecies

Question 6

sister taxa share a common ___

Answer 6

node

Question 7

what are 4 pieces of information that systematics collect

Answer 7

1. morphology
2. behavior
3. DNA sequences
4. biochemistry

Question 8

what is the principle of parsimony

Answer 8

a set of nested relationships that minimizes the # of times a character changes states
- chose the phylogeny that requires the fewest # of evolutionary events (b/c it’s more probable!)

Question 9

a shared, derived state/ condition is the same as a

Answer 9

synapomorphy

Question 10

which is useful for reconstructing phylogenetic relationships (synapomorphies / symplesiomorphy)

Answer 10

synapomorphies

Question 11

explain homologous character states

Answer 11

they look the same and have the same evolutionary origin

* cladistics work best when all character states are homologous

Question 12

explain analogous character states

Answer 12

appear the same but they actually evolved independently (convergent evolution)

• shared between species that was also present in common ancestor
• molecular evidence (DNA- ACTGs) can also be used to infer homologies

Question 13

errors in phylogenetic reconstruction can occur when

Answer 13

you fail to recognize that states are analogous rather than homologous

Question 14

more matched bases (molecular phylogenetics) between species means they’re _______(more/ less) likely to be closely related

Answer 14

more

Question 15

What is convergent evolution?

- relate to analogous traits

Answer 15

• independent evolution of similar traits in different lineages
• Analogous traits are structures in different species that are similar due to separate ancestries. The way they arise is explained by convergent evolution

Question 16

Define the ideal taxon

Answer 16

MONOPHYLETIC group (clade)
contains a common ancestor and ALL of its descendants and no other unrelated taxa

Question 17

monophyletic groups must use traits that are _______ because of _____ ______

Answer 17

similar

common ancestry

Question 18

define a polyphyletic group

Answer 18

taxa get lumped together even though they do not share recent ancestors
- more than one common ancestor
or
- lacking common ancestor that unites members in the group

this is a mistake! they’ve been grouped by superficial similarities, not common ancestries

Question 19

define a paraphyletic group

Answer 19

• groups that do not contain ALL descendants of a common ancestor
• often the result of the removal of taxa that are highly divergent from the rest of the clade
• usually make mistake b/c some descendants appear different from other members of clade

(this is also a mistake like polyphyletic groups- the goal is monophyletic groups!)