lab exam
why do you think it is so difficult to resolve these very deep branches of the tree of life?
- hypotheses not facts- the concepts can be explored and tested - collection of organisms can be rejected and adjusted
Examine the choices below, and select all those that are true of Eukaryotes. Please note, there is a guessing penalty for incorrect selections.
- membrane bound organelles - linear DNA packaged into chromosomes - a membrane bound nucleus
species
- the smallest level of taxonomic levels - group of interbreeding organisms - biological species concept
how do population genetics define evolution? does it always involve selection and adaptation?
- they define evolution as simply the change in allele frequencies over time - recognize changes allele frequencies through natural selection and genetic drift
is algae a real monophyletic group? If not, what types of creatures are colloquially described as algae?
-not a monophyletic group bc they do not descend from a single common ancestor - some phylogenetic groups of algae include diatoms, dinoflagellates and cyanobacteria
A population that is believed to be in Hardy-Weinberg Equilibrium contains 6 alleles, and their frequencies are as follows: Allele A = 0.1 Allele B = 0.1 Allele C = 0.3 Allele D = 0.05 Allele E = 0.2 Allele F = 0.25 What is the frequency of heterozygotes in the population?
0.785
steps to test allometric relationship between trunk diameter and plant height:
1. get images with appropriate scales for dimensional analysis 2. get image analysis program to assist in imagine quantification and data storage 3. record the data 4. analyze the data and reporting it on a single page
Four Observations of evolution through Natural Selection
1. more individuals are born than the environment can support 2. there are differences between individuals 3. some of these differences confer a reproductive advantage 4. these differences have a genetic basis ** when these are met, natural selection can occur
expected distance (rE)
1/(2*square root of D)
In an effort to estimate the population size of Siberian Tundra Lemurs in a fenced wildlife preserve, you capture and 'tag' 20 lemurs by giving them little hats. The lemurs like these hats and wear them all the time. A month later you return and this time you capture 22 lemurs. 15 of these recaptured lemurs have hats on them. What is the best estimate of population size in the wildlife preserve?
29:30
The meadow happens to be a perfect square which is 100 meters on each side. You divide the meadow into 40,000 0.5 meter quadrats. You decide you have enough time to count 8 of the quadrats, and obtain the following data: Quadrat #7 = 12 Quadrat #12 = 10 Quadrat #912 = 22 Quadrat #10532 = 3 Quadrat #22000 =15 Quadrat #35001 = 22 Quadrat #36859 = 2 Quadrat # 38824 = 9 What is the best estimate of the population size of violets in the meadow?
475000 violets in the meadow
genus
A group of similar species - first part is capitalized and the second name is not- they are both italicized
paraphyletic group
A monophyletic group in which some descendants of the common ancestor have been removed.
polyphyletic group
A taxonomic grouping consisting of several species that lack a common ancestor (more work is needed to uncover species that tie them together into a monophyletic clade).
C formula ( test statistic)
C= (rA- rE)/(0.26136/ square root of (N*D) -where N = number of bugs - if C is larger 1.96 or smaller than 1.96, then u can reject the null hypothesis ( that the organisms are randomly distributed) otherwise u cant
autapomorphies are:
Characters that are present in only 1 taxon on a phylogeny
A naive interpretation of Natural Selection is that individuals should never put themselves at risk to help another creature. Kin Selection is one model that has been proposed to resolve this apparent paradox. Which statement most accurately summarizes the Kin Selection hypothesis?
Cooperative behavior is evolutionarily advantageous when and individual puts itself at risk to save several close relatives because it shares many of its genes with these relatives. Even if the individual dies, the cooperative alleles will survive and be passed on to future generations.
cladogram
Diagram that shows the evolutionary relationships among a group of organisms
cladistics
Distinct character states, such as presence or absence of thorns or eye color.
You perform a survey of allele and genotype frequencies on a population that you hypothesize is not currently undergoing selection. There are only two alleles in the population and three genotypes. Based on your data, you calculate an X2 value of 14.85 and a Probability value of <<0.001. Which of the statements below is most correct?
Evolution is probably occurring, and you can reject the null hypothesis of Hardy-Weinberg equilibrium
phylogeny
Evolutionary history of a species or group of species.
what are some challenges or generating both polymers and organic molecules?
I - Creating organic molecules (amino acids etc) II - Creating a cell membrane III - Assembling organic molecules into polymers IV - "Bootstrapping" (making it all work together given that most of it won't work very well initially)
phenetics
Measures of continuous variables, such as arm length, brain volume, or %DNA similarity
been marker formula
N=M* C/R N is the total M is number of beans marked in first trial C is number of beans captured in second R is the number of marked re captured ** compared that to total number of beans
In the choices below, you will find a list of major events on the Timeline of Life. According to our best current understanding, which order is most correct?
Surface waters become possible | Biopolymers form | Stromatolite forming Prokaryotes evolve | Eukaryotes evolve via endosymbiosis | Arthropods evolve
You are studying a population of Gantry Oaks, and have determined that there is a negative allometric relationship between trunk width (y) and overall height (x). The general relationship is: y = 0.2xα, and α = 0.85. The smallest trees in your data set are 1 meter tall have trunks 0.2 meters wide. How wide do you expect the trunk of a tree to be if it's 10 meters tall?
The 10 meter tall tree has a trunk 1.42 meters tall. (2 significant digits is fine here)
what is an amphioxus
a Lancelot that is caught for food in parts of Asia
google earth
a free mapping program- important to map all of the trees to make sure that one tree isn't being used more than once
what is an outgroup?
a group of organisms not belonging to the group whose evolutionary relationships are being investigated- different then the rest of species in the tree
software intensive program
a system where software influences to a large extend the design, construction, deployment and evolution of the system as a whole
confirmation bias
a tendency to search for information that supports our preconceptions and to ignore or distort contradictory evidence -scientists search for what they believe to be true
You measure the nearest neighbor distances between ant nests in a field. You find that rA is much much smaller than rE. The ant hills can be said to be...
aggregated
stage micrometer
allows you to estimate the size of the creatures you examine
protozoa mix
an informal perform for single celled eukaryotes, either free-living or parasitic, which feed on organic matter such as other microorganisms or organic tissues and debris
Volvocales
an order of flagellated or pseudo ciliated green algae
Select all plant groups that use vascular tissue to circulate fluids and nutrients.
angiosperms. pteridophyta, gymnosperms
deuterosome
anus first mouth second
what is algae?
any photosynthetic protist that lives in water - contains chlorophyll but lacks true stems, roots, leaves and vascular tissue
rA (formula)
average distance between all neighbors / N
why do we think that HWE as a null hypothesis in evolutionary biology?
bc HWE predicts that both allele and genotype frequencies to remain constant from one generation unless something perturbs them - forces that alter allele frequencies are at the heart of evolutionary chance
why does it not matter that you know the number of times you play the game?
bc the outcome is random and you cant predict what your going to get
why do we say that chimps aren't the ancestor to humans
bc they share the same family but not the same genus
costs in payoff matrix
can be measured in energetic terms or in terms of reduced reproduction or survivorship
benefits of payoff matrix
can be measured in terms of number of offspring, energy gain, increased prob of survival, economic gain - b > c
what hypothetical solutions have been proposed?
challenge 1: 1 - Reducing Atmosphere/Primordial Soup 2 - Deep Sea Vents 3 - Extraterrestrial (panspermia) challenge 2: Amphipathic molecules, perhaps aided by clay particles challenge 3: Charged clay particles holding organic molecules in place? challenge 4: Lots of time and false starts along with Natural Selection; RNA World?
p-hacking
choosing a subset of the data that shows P<0.05 while ignoring the test
overall approaches in estimating phylogenies?
cladistics and phonetics
allometric growth
different parts of the body will grow at different rates - so negative is when the body gets smaller as the organism grows ex: head growth- as the body gets large, the head gets smaller - plants show allometric patterns, the growth of the trunk diameter and the height are generally proportional
tree allometry
establishes quantitative relations between some key characteristic dimensions of trees and other properties. -narrows the definition to applications involving measurements of the growth or size of trees
DNA sequence data can be useful when using cladistic approaches to estimate phylogenies. True or false?
false
In humans, the chief advantage of the HbS allele is that it confers resistance to malaria in mosquito rich environments when people are homozygous ( HbS / HbS ). true or false?
false
what can cause allele and genotype frequencies to change?
genetic drift, migration, mutation, selection, non random mating
monophyletic group
group that consists of a single ancestral species and all its descendants and excludes any organisms that are not descended from that common ancestor
HARKing and Naive realism
hypothesis after results known
monophyletic
if all members can trace their roots back to a single common ancestor
migration
if individuals enter and leave a population, its quite possible that they will alter the allele and genotype frequencies
what happens if R is larger than 1? smaller than 1?
if less than 1, more aggregated (clumped) and not as randomly distributed
selection
if some genotypes survive better than others, we expect allele and genotype frequencies to change over time
Bryophyta
key features: photosynthesis, nonvascular, cuticle Taxonomic rank: division ex: common liverwort, polytricnum commune
gymnosperm
key features: seed producers, cuticle, land plants, multicellular, chloroplasts, vascular system taxonomic rank: class ex: conifers and cycads
angiosperm
key features: vascular seed plant, fruits are made, flowers taxonomic rank: division ex: dicotyledon, cactus
Pteridophyta
key features: vascular, produce spores, no flowers or seeds, first true land plants taxonomic rank: phylum ex: wisk fern, flying spider monkey, tree fern
Density formula
mass/volume
You study a population of giraffes and you have measurements of both total height and femur (leg bone) length. You perform calculations similar to those we did in lab using height as the x variable and femur length as the y. You calculate an α (alpha) value of 1.43. If one giraffe is twice as tall as another, you expect the femur of the larger giraffe to be:
more than twice as long as the femur of the smaller giraffe
4 steps of nitrogen cycle
nitrogen fixation, ammonification, nitrification, and denitrification
mutation
novel alleles are generated occasionally through mutation
standard taxonomic ranks
phylum-class-order-family-genus-species
5 distinct kingdoms
plantae, fungi, Animalia, protista, monera
R formula
rA/rE
Cnidaria and Ctenophora & echinoderms have what kind of symmetry? Proferia?
radial ; no symmetry
allometry
science of size and its consequences - range of sizes possible for living things based on the biology of the individual
selective reporting
scientists ignore experiments that don't support their hypotheses
Synapomorphies
shared derived characters
Rhizobia
soil bacteria that fix nitrogen after becoming established inside root nodules of legumes -one of a small amount of organisms that can use nitrogen directly from atmosphere
kin selection theory
suggests that individuals help close relatives with which they share some of their genes, and therefore by telling them they are helping the survival of those shared genes
reciprocity theory
suggets that individuals help other non related individuals in the hope that they will reciprocate - the benefit of helping is greater than the cost and reciprocity is favored
dichotomous key
system of questions that can allow you to identify the exact species you are examining
How good would your estimate be in Question 5 if you were unaware that many of the hat wearing lemurs were altruistic and returned to the traps hoping that they could get additional hats to share with their close friends?
the estimate in question 4 would be too low
zero sum games
the interest of the individuals are in total conflict; possible biological examples are the interactions between predator and prey - expect totally selfish behavior
non zero sum games
the interest of the two individuals partly coincide and are partly opposed - bc there are at least some shared interest between the players, hames like these can potentially lead to cooperation
phylogenetics
the science of evolutionary relationships
what is the taxonomic rank of protists?
the taxonomic rank is the relative level of a group of organisms in taxonomic hierarchy such as species and then genus and family, order, class phylum and kingdom and domain
how are the major groupings of plants related?
they are land plants that share the common ancestor of green algae
what damage do lamprey do?
they attach to host fish and puncture its skin and drain its body fluids usually killing them
why are phylogenetic trees useful?
they reflect the hierarchy of living things
According to the video you watched, Dr. Anthony Allison noticed that there were relatively low frequencies of Sickle Cell anemia in the dry areas around Nairobi, and relatively high frequencies in the wetter areas near the coast and near Lake Victoria. True or False?
true
Changes in allele frequencies resulting from genetic drift are considered to be evolution. True or false?
true
p-hacking involves picking and choosing parts of a large data set until one finds a pattern that is statistically significant. true or false?
true
game theory
used in evolving populations in biology- defines the frame work of the analytics which darwinian competition can be modeled after
Select all Synapomorphic Characters that unite the Pteridophyte, Angiosperm, and Gymnosperm groups
vascular tissue
What if the beans were smart enough to avoid your fingers the second time they saw them? What if they liked your fingers?
we would capture less; we would capture more
isometric growth
when all body parts grow at relatively the same rate
nitrogen cycle
when nitrogen is converted into multiple chemical forms as it circulates among atmosphere, and diff types of ecosystem
genetic drift
when populations are small, allele frequencies can chance just due to sampling error
mutual grooming
where individuals remove parasites - there is obvious benefits to be gained form getting someone to pull off parasites -however, one individuals might do even better by not cooperating ; if it let other individuals get rid of its own parasites without paying the cost of time and energy in reciprocating
iterated prisoner's dilemma
where the prob of reencountering the same individual is high
is there an easy way to calculate expected heterozygosity when you have dozens of alleles in a population
yes through basic algebra - p2+2(pq)+q2=1