Biology Test Evolution Flashcards

Terms Definitions
Humboldt
Explorer
apomorphy
new trait
Autotrophs
photoautotrophs-photosynthetic. use light as the source of energy and CO2 as source of carbon • Chemoautotrophs (= chemolitothrophs):– Obtain energy by oxidizing inorganiccompounds. May use sulfur or nitrogen as the basis for reactions. Get carbon from CO2
Modes of Reproduction
Asexual
Unisexual
Sexual
Asexual/Sexual
phenotype
The physical, observable characteristics determined by the genotype of an organism.
Measuring Dispersal
Mark recapture
-time consuming
-limited returns
 
Satellite tags
-small N
-limited time
-can't measure gene flow
-expensive
-battery life
-only looks at movement, not gene flow
-don't know what they are doing
 
Genetic Markers
-long period of time... 10s of thousands of years
-gene flow in both directions is not equal
-non-linear relationship b/w Fst and Nm (assumes gene flow occurs bidirectionally and equally)
 
Nm is the net # migrants
=
migration rate*population size
macroevolution
large-scale evolutionary changes that take place over long periods of time
structural homologies
bones of all mammals
intrasexual
male-male competition for females; often results in body size sexual dimorphism
mutualism
interaction between two organisms, each individual derives a fitness benefit
Drawing of tetrapod vertabrate forelimbs similarities.
Convergence can also be called
homoplasy
industrial melanism
(the peppered moth)
darkening of populations of organisms over time in response to industrial pollution
theory
a well supported and testable explaination
Gradualism
Branching from one ansester slowly farthering themselves from one another
evolutionary reversals
distantly related taxa show similarities because of a reversal to ancestral (original) state
During a study session about evolution, one of your fellow students remarks, "The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result." Which statement is most likely to be helpful in correcting th
B
gene flow
migration of individuals between populations
Vicariance
splitting in rage of a taxon
Fact
An OBSERVATION that has been REPEATEDLY CONFIRMED
Willi Hennig
1966- modern practice of phylogenetics; used shared derived characteristics (synapomorphies) to create monophyletic groups (clades)
Evolution
Change of a species over time.
Population
In biology, a group of similar individuals that can and do interbreed.
premating habitat
populations live in different habitats and do not meet
Sexual selection
"the fitness advantage that some individuals have over others of the same sex solely with respect to reproduction"
First organisms of life
Bacteria, 3.8 billion years
Define Population Structure.
Patterns of genetic differentation among populations of a species
 
This includes:
- Quantification of population structure and genetic diversity within populations
- Interaction with gene flow
- Interaction between genetic drift, gene flow, and selection
 
Example: Collared lizards
Finches
on the Galapagos Island, good example of adaptive radiation, under Darwin's care
The average birth weight for human babies is about 3 kg. Which of the following terms best describes this?a. disruptive selectionb. artificial selectionc. directional selectiond. sexual selectione. stabilizing selection
E
Speciation
the divergence of one species into two.
quantitative genetics models
selection response for continuous trait
artificial selection
-like natural selection, but humans select traits
 
-flower development...
CAULIFLOWER gene
-254 aa long, and binds to DNA to activate other genes
-multiple alleles
APETALA1 gene
-functionally similar to CAULIFLOWER
 
-cauliflower, broccoli, burssel sprouts, kale, kahlrabi, cabbage are all from same species
 
-species has both CAULIFLOWER and APETALA1
-many different flower results depending on whether these are normal or mutant
 
-in cauliflower plant, found that at a.a. 151, GAG was TAG (mutation that created stop codon)
-one nucleotide substitution, and therefore premature termination
 
-in wild cabbage, 2/11 alleles had premature termination
-in kale, 3/7
-in brocoli, 8/9
-in cauliflower, 10/10
 
**domestication selected for mutant CAULIFLOWER allele
What is adaptation?
Any inherited characteristic that increases an organisms chance of survival
analogous structure
Structures found in various species that may have the same function, but have originated from somewhere different on the evolutionary chain.
neutral variation
Genetic diversity that confers no apparent selective advantage.
Mutation
 
When DNA copies itself incorrectly, it results in a mutation. This is one way of introduction variation into a population.
a group of closely related organisms capable of mating and producing fertile offspring
species
gene pool
total genetic information in the gametes of all the individuals in a population
punctuated equilibrium
pattern of evolution in which long stable periods are interrupted by brief periods of more rapid change
hybrid sterility (postmating)
hybrids do not produce functional gametes
Reticulation
The blending of two lineages into one lineage (hybridization/viruses)
Parallel Evolution
Different spicies but very close in common since they have adapted to the same conditons
Natural Selection
process by which individuals that are better suited to their environment survive and reproduce most successfully; also called survival of the fittest
Which of these is a statement that Darwin would have rejected?a. The smallest entity that can evolve is an individual organism.b. Environmental change plays a role in evolution.c. Individuals can acquire new characteristics as they respond to new environm
A
cladogenesis
branching of a lineage into two or more descendant lines
Archaen eon (precambrian)
Origin of life-radiation of prokaryotes (cells without nucleus)
stabilizing selection
reduces amount of variation in trait (bell curve becomes less wide)
How often to reproduce?
semelparous-
-reproduce once and die (no future reproductive costs)
-annual plants, salmon
 
iteroparous
-more than one brood uring lifetime, fewer yong
-balance current investment with future costs
-eg. perennial plants, bears
 
intergenerational time is very important!!
-assuming same lifespan (1yr) and same number of offspring (3)...
-if breed every 3 months, end up with 120 offspring, if breed every 12 months, get 3.
What is Paedomorphosis?
the retention of juvenile structures in a sexually mature adult
What is fitness?
Idividauls that survive to greater chance of producing more offspring, to pass on charachteristics.
Limnetic stickleback
slender, mouth and eyes positioned for feeding on plankton, closely spaced gill rakers
idea that says that organisms with favorable characteristics survive and reproduce at a greater rate
natural selection
Principle of Segregation
Each unit pair separates in gamete production, so that each gamete contains 1 member of each pair.
During fertilization, individual units come togeher
temporal isolation
when 2 populations are able to breed, but reproduce at differnt times
Define Microevolution
a change in gene frequency in a population over time
what is recombination rate?
how frequently chromosomes break and cross-over
 
One of the most convincing pieces of evidence Darwin used to defend his theory was:
 
A. DNA evidence
B. embryology comparison
C. fossils
D. genetic similarities
 
 
 
C. fossils
ingroup vs. outgroup
Outgroup: taxon that diverged prior to the most ancient node on a tree. Ingroup: All organism that share a common trait that do have known nodes and ancestors-EX: Jaws. Animals with jaws are ingroup, animals without jaws are outgroup
When was last common ancestor of ALL humans?
Approaches...
 
mtDNA (mitochondrial Eve.. last female common ancestor).. 140-200kya
Y chromosome (common male ancestor.. 60-80kya)
-times are different
-difference due to when lineages went extinct
 
MITOCHONDRIAL EVE
-recall that some lineages become extinct
-does not mean single female present
-does mean that all modern individuals descended from common female
 
 
One disproportionately common Y chromosome haplotype
TMRCA (time to most recent common ancestor) 1000 years ago in Mongolia
 
Genghis Khan!
-hordes of soldiers kill men and rape women.. leave haplotype
What are homologous embryos?
Similar embryos in different species that show common ancestry
Sexual Selection in plants
Male and female orchid flowers originally described as 2 species
-access to pollinators restricts reproductive success
 
WILD RADISH
-single coour gene W=white, w=yellow
???? look at slides
Theory of biogenesis
states that only living organisms can produce other living organisms
the amount of time it takes for one half of an isotope sample to change and become a new element is the isotope's
half-life
Why would the Amish have a higher incidence of polydactyly than average?
the Founder Effect
why are human gene mutations so rare?
we have proofreading capabilities.
Difficulties in tree Building4)
Some lineages diverge so rapidly that there is little opportunity for the ancestors of each monophyletic group to evolve distinctive synapomorphies (rapid divergence of lineages)
Mass Extinctions
In the last 570 million years, as many as 20 mass extinctions.
-end of Ordovician, Devonian, Permian, Triassic, and Cretaceous
-big five responsiblefor 4% of all extinctions
-over 50% of families extinct in Permian
 
The larger the geographic range, the lower the extinction rate, and the higher % chance of survival
 
ORDOVICIAN (440 MYA)
-jawless fish, plants and terrestrial arthropods present
-marine invertebrates: 22% families and 60% genera extinct
-glacialmaximum exposed sea sheles and flooding of shelves with freshwater from melting.
 
PERMIAN (250mya)
-llarget... 49% marine animal families, 63% terrestrial organisms
-Pangea formed at that time
-ocean cirulation poor.... low oxygen in water
-deep water enriched with methane and hydrogen sulfide
-as ocean currents started again, released large amounts of CO2 into atmosphere
-volcanic activity in eastern Russia (area the size of Gulf of Mexico)
-all of this resulted in increased temp of 6C
-took about 100MY for biodiversity at family level to return to pre-extinction levels.
 
CRETACEOUS (65mya)
-50% of extant genera became extinct
-invertebrates affected
-dinosaurs already declining
-large scale fires
-soot deposits several cm thick
-seed plants survived suggesting major fires were short lived (ie. dormant seeds)
-meteor impact.. Yucatan Peninsula
-may predate extinction by 300ky
-ejected debris into atmosphere, tsunamis, fires
 
meteor 10-15 km wide
-high levels of iridium found in meteors
-180km wide crater
-ocean floor where meteor hit had large amounts of anhydrite (CaSO4)
-vaporized releasing SO2 and water (H2SO4)
-acid rain and global cooling (particles scatter light)
-extinctions occurred up to 500ky after impact
 
Following mass extinctions, 'direction' of evolution changed
-end of Permian.. radiation of amniotes
-end of Cretaceous... mammal radiation
 
OTHER CATASTROPHIES
Volcanoes..
Krakatoa (indonesia) 1883
-tsunamis in Japan and west coast of N America
-Cascade and Sierra Nevada Mountains
-ash 2000km away in Nebraska burying herds of woolly rhinos
-1815 another Indonesian volcano (global temp decreased 3C)
 
-glacial dams.. Lake Missoula formed by arm of Colubia ice field
-tsunamis.. 1964 Alaska earthquake.. waves destroyed structures 200m above sea level.
 
BURGESS SHALE
-formed 520-515 mya when plate hit west coast of North America
-AB/BC border was west coast
-shallow sea floor pushed above sea level and covered by mudslide
-some organisms look like etant species, but many extinct lineages
-most invertebrates and some algae
 
Opabinia regalis
7cm long, feeding appendage, segmented, 5 eyes
Competition or Predation
Arises between two or more species who use the same resource when that resource is finite and limited.
parallel evolution
when 2 or more species evolve from a commmon ancestor but remain somewhat similar thru time
Why is there still heritable variation for traits directly correlated with fitness?
Possibilities:
1. Balance between new deleterious mutations and selection: bad mutations always popping up, but not so bad that they are not viable.
2. 'Fisher's Fundamental Theorem' hypothesis: lots of great new mutations constantly arising! This creates genetic variation.
3. Diversifying selection, and/or selection favoring different traits in different times or places.
Homeotic genes (hox genes)
-a group of genes that specify the anterior and posterior segments of animals-specialized gene for a specific part of an organism's structure
What publication helped Darwin confirm his beliefs on the formation of the Andes? What as the main theory in this publication?
Charles Lyell wrote Principles on Geology that explained geological phenomina as occuring over millions of years.
 
This change was described as uniformitarianism
What is comparitive Embryology?
It is the comparison of human embryoes to no-human embryoes.
Are there limits on species diversity?
It is widely accepted that resources limit the number of individuals in a population, iti is far less clear hwo resoureces could place limits on the number of species. Species richness does vary with latitude, but for macroevolution abiotic factors, rather than resource limitation may play significant role
Replicated sister group comparison
Diversity of a number of clades with a novel character can be compared with the diversity of their sister groups that retain the ancestral character state
what type of boat was the HMS beagle?
Cherokee class survey ship
 
called the "Coffin Brig" because they sank so much
why does HIV evolve so rapidly?
- high mutation rate- short generation time, extremely large pop size
which of the Darwinian steps has the biggest influence from environment
natural selection because that's when organisms die or live on
neutral theory of molecular evolution predicts that
all of the above; -proteins subject to weak selective contraints will evolve at rapid rates-the rate of protein evolution is roughly constant per site per year- the rate of neutral evolution is independent of population size-the majority of protein polymorphisms in natural populations are neutral
What are the two types of sexual selection and what are they?
Intrasexual Selection - members of the same sex compete against each otherIntersexual Selection - one gender is influencing the other gender, selection of the individuals of the opposite sex
If there is no selective pressure, then DNA sequences should...
diverge at a constant rate. Which is the basis of molecular clocks.
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