bi107 quiz 3

common ancestor

all of life is related through a _______________

homologous structures

most synapomorphies are also

lineage

series of ancestor and descendant populations

phylogeny

Evolutionary history of a species or group of species.

phylogenetic tree

A family tree that shows the evolutionary relationships thought to exist among groups of organisms

- all life forms
- major evolutionary groups
- small groups of closely related species
- individuals
- populations
- genes

phylogenetic trees are hypotheses of the evolutionary relationships of...

root

the common ancestor of all the organisms in the tree forms the ______ of the tree

node

indicate timing of splitting events

splits

in a tree of species this represents a speciation event

splits

in a tree of genes this represents a genetic duplication event

no

if you rotate around a node does the layout of the tree change

false

T or F vertical distances between branches have a meaning

taxon

any group of species designated with a name

clade

any taxon that consists of all the evolutionary descendants of a common ancestor

...

evolution can be defined as descent w modification

biological classification

evolutionary relationships form the basis for....

homologous feature

similar features that originated in a shared ancestor

- DNA sequences
- protein structures
- anatomical structures
- behavior patterns

homologous features can be heritable traits in the form of ...

character

a general category for which species manifest different staes

- wings
- floral nectar
- leaves
- eye color

types of characters

- A, G, C, T
- hairy/not hairy
- present/absent
- brown, blue, green

types of character traits

derived trait

newly evolved features that do not appear in the fossils of common ancestors

ancestral trait

A trait shared by all members of a group through a common ancestor.

Synapomorphy

shared derived traits that provide evidence of the common ancestry of a group

convergent evolution

when superficially similar traits evolve independently in different lineages

wings evolving in bats and birds but not in other ancestors between them

example of convergent evolution

analagous structures

Similar function but different structure - does not show common ancestry

example of analagous structures

Bat, insect, and bird wings

evolutionary rehearsal

when a character reverts from a derived state back to an ancestral state

homplasy

similar traits gained (convergent evolution) or lost (evolutionary rehearsals) in separate lineages over time

Birds have wings to fly and bats have wings to fly but they evolved differently as bats are mammals

example of homoplasy

point of reference

a trait may be ancestral or derived depending on the...

ancestral trait

in a phylogeny of all living vertebrates, feathers are a derived trait, but in a phylogeny of only modern birds they are an

ingroup (phylogenetic tree)

the group of organisms of primary interest

outgroup (phylogenetic tree)

species/ group known to be closely related to, but phylogenetically outside of, the group of interest ( 1 individual who is phylogenetically separate from the ingroup)

more closely related than taxa who have less shared traits

taxa who share derived character traits should be

character matrix

an array of taxa (at left) and characters (at top) that contains the character states for the taxa

parsimony principle

the simplest explanation of observed data is the preferred explanation

minimized

in phylogenies, the number of evolutionary changes that need to be assumed over all characters in all groups is....

fewest

the best hypothesis is the one that requires the __________ homoplasies

- morphology
- developmental traits
- fossil record
- behavioral traits
- molecular traits

traits that are genetically determined that can be used in a phylogenetic analyses

- reconstructing past events
- forensic investigations that involve viral transmission
- compare and contrast living organisms
- reveal convergent evolution and reconstructing ancestral states

why is a phylogenetic tree useful?

divergences

molecular clocks can provide information on timing of

lineage splits

rates of molecular clocks are constant enough to predict the timing of ....

they use the average rate at which a given gene/protein accumulates changes

how do molecular clocks gauge the time of divergence

calibrated using independent data

molecular clocks must be

binomial nomenclature

Classification system in which each species is assigned a two-part scientific name (genus species)

kingdom
phylum
class
order
family
genus
species

taxonomy (king phillip came over for good soup)

monophyletic group

the group that consists of a single ancestral species and all its descendants and excludes any organisms that are not descended from that common ancestor

cut

a true monophyletic group can be remove from a phylogenetic tree by a single _____

polyphyletic group

a group that doesn't include its common ancestor

paraphyletic group

a group that doesn't include all the descendants of a common ancestor

stratigraphy

much of Earth's history is recorded in rocks

progressively younger

in sedimentary rock layers, the oldest layers are at the bottom and the higher strata are ....

The oldest of the Precambrian eons; no life on earth (4.5-4.6 bya)

hadean eon

origin of life (3.8 bya)

Archean eon

evolution of photosynthesis (2.5 bya)

proterozoic

beginning of the paleozoic era

cambrian period

phanerazoic

name of our present day eon

anaerobic

all early life forms must have had what type of metabolism?

the great oxygenation

2.5-1.8 bya
when the first aerobic bacteria came to life
- shift in metabolic pathway

cyanobacteria, it Split water as a source of hydrogen ions for photosynthesis

what first released oxygen during the great oxygenation

the slow rise of O2 levels

1.8- 0.8 bya

- atmospheric oxygen rose because of a balance of photosynthesis and respiration
- ozone layer formed which allowed for life on land

it reduced radiation from the sun hitting the planet

how did the ozone layer allow for expansion of life on land?

anaerobes in most of Earth's environment

as oxygen accumulated, organisms with aerobic metabolisms replaced _______

1.5 bya, a cyanobacteria-like ancestor became symbiotic within eukaryotic cells

how did chloroplasts develop

the rapid rise of O2 levels

850-500 mya
burial of organic matter due to tectonic shifts

highest o2 values

320-275 mya
diversification of large land plants

rapid drop of o2 levels

250 mya
96% of multicellular species went extinct
largest mass extinction event
massive volcanic eruptions caused climate cooling
swamps dried up (used atmospheric o2)

permian extinction

largest mass extinction event

radiation-

rapid speciation event

cambrian explosion

rapid diversification of life, evolutionary radiations

ethology

study of animal behavior

1. Causation
2. Development
3. Function
4. Evolution

Tinberg's Four Questions

Causation

what is the mechanism underlying the behavior?
how can mechanisms be modified by learning?

development

what experiences are necessary for a behavior to be displayed?
- imprinting, learning, environmental effects, changes with age

function

how does the behavior affect the animal's chances of survival and reproduction?

function

Does dispersal increase reproductive success in mice? is an example of what type of question

evolution

how might have the behavior evolved?
similarities to related species?
- phylogenetic history of the behavior

immediate mechanisms that underlie behavior
(ie: causation and development)

proximate questions

evolutionary processes that produced the behavior
(ie: function and evolution)

ultimate questions

receives info from the environment and coordinates a response

in animals, the nervous system

species-species instinctive behaviors

- performed without learning
- performed the same way every time
- not typically modified by learning

fixed action patterns

mother goose chasing after the egg and going back to the nest even though it rolled away

example of a fixed action pattern

biological determinism

an individual's behaviors are fixed by their genetic makeup

behaviors

gene expression can change at certain stages in an organism's life which can lead to differences in

to what extent is behavior shaped by genetic variation vs past experience, learning, or other environmental influences

nurture vs nature

multiple genes have to be expressed and interact in order for a given behavior to be performed

what leads to a specific behavior being performed

for the first 3 weeks, they are nurse bees (caring for the young), and then from day 23-42 the gene expression changes and they become foraging bees

example of behavioral genetics

epigenetics

DNA methylation and histone modification can change gene expression without changing the underlying DNA sequences

Learning

acquired changes in. behavior during one's lifetime

innate learning

fixed action patterns are an example of

1. conditional reflex
2. imprinting
3. cognitive learning

three types of learned behaviors

conditioned reflex

A simple relation between a specific conditioned stimulus and a conditioned involuntary response.

pavlov's dog salivating at a metronome when no food's around because he heard a metronome at mealtimes

example of conditioned reflex

imprinting

the process by which certain animals form attachments during a critical period very early in life

conservation biologists dressed as whooping cranes to not affect the imprinting of cranes in their labs

- the number of cranes went from 30 to 800

example of imprinting

Emlen Funnel

funnel with ink pad on bottom, paper on funnel walls, use in planetarium; radial patterns on funnel indicate direction animal is trying to fly

1. prevented from seeing night sky at all
2. recreated the natural sky
3. portray an incorrect sky (different axis of rotation

three ways the emlen funnel modified the sky

anywhere. they had no directional information

the indigo buntings that didnt see the night sky in the emlen funnel ended up going ...