Past Labs
True or false: variation is not needed for evolution
What is false
In a phylogenetic tree, what are "taxa"?
What is the individual groups
True or false: initially when building a tree, we assume no relationships among the taxa
what is true
Name a good outgroup for a tree depicting ants, cockroaches, beetles, grasshoppers, and bees
What is (anything that is not an insect)
When are your TA's office hours
What is (varies between labs)
define "the biological species concept"
what is a concept that defines a species as members of populations that actually or potentially interbreed in nature, not according to similarity of appearance
What is a "character"?
what is a trait that may or may not be shared between individuals
What is the first step in designing a tree?
what is finding a shared character between all ingroup members, but not the outgroup
What is the purpose of a phylogenetic tree?
What is to collect, organize, and compare the physical features and/or DNA sequencing of genes for species
True or false: More closely related taxa will share more character states
What is true
Is evolution occurring? Why or why not?
Observed: TT: .05 Tt: .8 tt: .15
Expected: TT: .40 Tt: .25 tt: .35
What is yes, because there is an observable difference between observed and expected values
define "outgroup"
What is a close relative of the group being studied that has some shared characters and some different characters as compared to the ingroup
How are ancestral character states coded in a character state matrix?
What is as "0"
What is the first step in creating a phylogeny based on morphological characters?
What is identifying and collecting information on traits that are shared between study organisms or specific to certain groups
Name two types of asexual reproduction
What are budding and fission
Provide two qualitative and quantitative observations you might make of a beetle
Qualitative: What are (colors, presence or absence of a feature, types of markings, etc)
Quantitative: What are (count of features, measurements of features or parts, etc)
define "apomorphy"
what is a derived or “new” character not found in recent ancestor(s)
What do the numbers in a phylogenetic tree represent?
What is the character and which trait type is displayed; e.g. character 2, character trait type 3: 2(3)
Where would you expect to see the outgroup on a phylogenetic tree?
What is the furthest back in time, related to all of the ingroup, but not directly attached to any single taxa
What is the difference between microevolution and macroevolution?
What is Microevolution are changes within a population over generation (single species) WHILE Macroevolution is an evolutionary change that results in different species (speciation)
Define this scenario: a population of 1000 lizards on an island is threatened snakes which kill off 950 of the lizards. Eventually the lizard population grows back to a population size of 750.
What is the bottleneck effect (population bottleneck)
What is the difference between a "plesiomorphy" and a "symplesiomorphy"?
what is a plesiomorphy is an ancestral character and a symplesiomorphy is a shared ancestral character
What two assumptions must be met for outgroup comparisons to work?
What are
1. the ingroup doesn't include any very close relatives to the outgroup
2. the outgroup isn't too closely related that it is considered a part of the ingroup
Based on the Hennigian argumentation technique, why would you see a 1, 2, or 3 in the state code matrix comparing groups?
What is there are 3 different derived characters different from that of the outgroup. (e.g. horns, antlers, or spines, while the outgroup has a smooth head)
What happens in a mutation meltdown?
What is over time in asexual populations, the proportion of low fitness individuals with many deleterious alleles increases; Eventual consequence = extinction