Biology Evolution 2 Flashcards

Terms Definitions
evolutionary history
Lewis and Clark
Protein Synthesis
1. Transcription
2. Translation
inherited characteristic that increases an organism's chance of survival
non-random distribution of organisms
-continental regions have relatively uniform distribution of plants and animals
-organisms in some parts of the globe (ie. South America ad Australia) were much more unusual than others (ie. N. America and Eurasia share many similar species)
-animals of given continents were related to each other more closely than they were to elements from the biotas of other continent
-similar regions defined on the distributions of plants, soil type, and climate
endemics- groups found only in one particular region
-73% mammalian families endemic to one faunal regions
-six faunal regions (plus oceana.. islands)
-look at these in text.. cannot read off slide
-usually less than half are endemic
deceptive coloration
fake eyes, fake head
similar structure, but dissimilar function.
a common ancestor
(whale fin, an bird wing)
Which describes brightly colored peacocks mating more frequently than drab peacocks?a. stabilizing selectionb. artificial selectionc. directional selectiond. sexual selectione. disruptive selection
Selection for codominant
1, 1+S/2, 1+S
Types of evolution
gradual- happens slowlypunctuated-happens quicklyconvergent-unrelated but resemble one anotherdivergent-evolved fro a common ancestor but they adapt based on their enviromentCo-evolution- 2 species evolve because of changes in each other over timeadaptive radiation - small group of species evolves into diverse forms
hybrid sterility
survives but is sterile
geographical distribution of species - islands usually have species similar to and closely related to the mainland island
Dobzhansky-Muller incompatibility
When hybrids experience reduced fitness due to the joining of two different derived alleles.
Day active primates including monkeys, apes, and humans.
Mendel's Principles
alleles account for variation; offspring inherit 2 copies of parent genes; dominant alleles mask other phenotypes; 2 alleles for a trait split during meiosis
Separation of populations of a widespread species or higher taxa-fish (certain) have close relatives on other side of Isthmus of Panama
Cretaceous Extinction
65mya85% species lost-dinosaurs and marine reptile extinct-mammals, birds, amphibians, and land reptiles were unaffected-Causes: massive meteor impact in Yucatan (iridium from meteor rocks found in cretaceous rocks)
Hardy-Weinberg model
assumptions - infinite population size, no selection, no mutation, no migration, random mating
How many islands in the Galapagos?
Unweighted pairwise group method with arithmetic average
1)estimate all pairwise distances
2)take smallest distance dAB=0.08, connect dOB=dOB=0.04
3)next smallest distance dDE=0.12
*This is using hypothetical genetic distance for five observational taxable units
*extant species (tips) are zero!
4)Now we need to connect OTU (B) that is already in a clade!
5)Finally, connect all clades
d=average dAD,dBD,dCD,dAE,dBE, and dCE
**Assumes all rates of evolution are equal
similar phenotypes that have evolved repeatedly and independently in similar habitats, benthic is an example
deviation in structure or character from others of the same species or group
new anatomical structure (arise in a stepwise fashion: adding new features onto old structures)ex: eyes: pigmented cells-->photoreceptors-->pinhole camera-->primitive lens-->complex camera
punctuated equilibrium
due to large environmental shifts, divergence occur abruptly with relatively little or no change at other times
adaptive radiation
the evolutionary divergence of members of a single phylogenetic line into a variety of different adaptive forms, usually with reference to diversification in the use of resources and habitats.
small changes in a population over time ex. color variation
what types of individuals are more viable, homozygotes or heterozygots?
Kin Selection
natural selection that favors the spread of alleles that increase indirect fitness
why do animals migrate
to lesson intraspecies competition
Hardy Weinberg assumptions
-population is large-no mutations affect gene pool-mating is random-no net migration in or out-genes in population are equally successful at reproducing
does not contain all successors of ancestor - "reptiles" does not include birds, so paraphyly
def. of nat. selec.
nonrandom differential reproductive success among individuals within a population
what percentage of eukaryotic DNA is functionable?
place on a chromosome where the nucleotide sequence is found that codes for a particular phenotype
reasonably accurate dating of fossils is possible by measuring the break down of ___________ in the rock
carbon isotopes
when all the population of a species dies out.
Green Algae (chlorophytes)
•Some are unicellular, some form colonies, multicellular forms •Chlorophyll a and b•Losts of morphological diversity•Volvox: no tissue or oranges but colonies with specialized cells (intermediate form of multicellular organisms with specialized tissues)
cast fossils
the branch that decomposes after it was burried and then left a hold
Saltational Response
Upstream parts could be altered which could cause large scale disruptions of regulatory pathways, with unpredicatble results. Only way that novel divergent body plans could arise, such as bilateral to radial symmetry.
Vestigal structures
remnants of structures that were used for one function in an ancestor but are no longer used for that function
Each of the following has a better chance of influencing gene frequencies in small populations than in large populations, but which one most consistently requires a small population as a precondition for its occurrence?a. Genetic driftb. Mutationc. Natura
relative dating
looking at columns of rocks and determining age by the position of the layers
phylogenetic species concept
smallest monophyletic group of common ancestry is a species.
basic unit of heredity in a living organism - "locatable region of genomic sequence"
vestigial organ
organ that serves no useful function in an organism
Biological Fitness
The ability to survive and reproduce in your environment
Thomas Malthus
economist, wrote an essay that argued human population growth is greater than the rate of increase in food supply, will lead to famine; inspired Darwin's theory of natural selection
frequency-dependent selection
A decline in the reproductive success of a morph resulting from the morph’s phenotype becoming too common in a population; a cause of balanced polymorphism in populations.
muscles that move ears
probable: better hearingwhy: turning our heads is the same thing
genetic equilibrium
the frequency of alleles remains the same over generations (Hardy-Weinburg Principle: p^2 2pg+g)
examples of genetic drift
bottleneck effect (decrease in a population size), and founder effect (small founding colony) causing random change in allele frequencies that occurs in small populations
Patterns of Diversity
variety in ways all organisms survive and reproduce
How life began
CHems in air and other variable randomly let it began with the sock of electrisisty
Piltdown Man
skull with human cranium and ape jow bone-faked
Plato - had philosophyeidos and essence
eidos- form/ideaessence - reality
selfish DNA
replicates itself in gene and makes no specific contribution to reproductive success
descent with modification
principle that each living species has descended, with changes, from other species over time
Reproductive Isolation
Occurs when a species evolves into a new species because all or part of the individuals in that species became isolated in a new environment.
sexual dimorphism in stickleback
males assume bright nuptial coloration while females remain drab during reproduction
natural selection
process by which life forms who adapt to their environment with traits tend to survive and reproduce
Bottle Neck Effect
can change gene frequency if small in size, if killed
For two linked, diallelic loc (C1C2 and D1D2), what are the HW genotypes?
Same as linked....I think.
Hardy-Weinberg Principle
A way to measure a shift of allele frequencies in a population States that the frequencies of the alleles should remain constant if there is no evolution occuring p^2+2pq+q^2=1, p+q=1No mutations, no gene flow, random mating, no genetic drift, no selection
Evolution by Natural Selection
Proposed by both Charles Darwin and Alfred Wallace, but Darwin is mostly credited.- organisms best suited to their environment reproduce more successfully and so the "favorable" genes are passed on more often (not an active process!)
Lamarck's theory of organic progression
over time, species originate by spontaneous gneration, and each evolves up the scale of organization, establishing a 'chain of being,' that ranges from simple forms of life, to older, more complex forms; DOES NOT BELIEVE IN A SINGLE COMMON ANCESTOR
Definition of
Homologous Structures
Two or more structures having the same typical structure and position, that also suggest common ancestry.
what is another name(s) for environmental variance?
Also called proximate variation or error variation.
mate choice (isolating mechanism)
two different species meet but do not recognize sexual cues
What were Darwin's 3 main conclusions?
1. Natural Selection2. Adaptation - born with traits that are fit for the environment3. The fit traits will be spread
3 approaches to studying natural selection in the wild
- testing for correlations between traits that vary geographically and environmental factors (presumably causing traits to vary)- comparisons between closely related sympatric species. This is usually done to detect character displacement.-comparisons between species living in similar habitats. this approach is used to detect either convergent evolution (if the species are very distantly related) or parallel evo (if the species are closely related.
Define genetic drift, and describe the drunkard's walk metaphor.
Genetic drift will ultimately cause the fixation of one allele and loss of the other (loss of genetic variation). Breaks H-W assumption of infinite population size and no sampling effects.
Drunkard's walk metaphor: as he staggers crookedly down the train platform, he will eventually fall off one side (fixation) or the other (loss). Rare alleles are more likely to be lost; the drunkard is more likely to fall off one side of the platform if he starts walking at a point closer to that side than the other.
Ex of an artificial selection
A farmer plants only the tall corns, eventallly all corn will be tall
How did Thomas Malthus influence Darwin?
Malthus saw that the human population was growing too rapidly, and that only certain factors keep it in check. Darwin wondered if the same thing happens in nature, and that animals produce much more offspring than can survive.
How did fossil shape support the theory of evolution?
Shows similarities between extinct and modern species.
how did D respond to his criticism?
he reprinted his book with his responses
concept of island biogeography and alterations
The point of this was to determine the idea of an equilibrium state in species richness. that results from a balance of colonization and extinction rates. You subsitute colonization with speciation and you also add the idea that extinction might not be competition dependent but rather sine are due to diversity independent modes.
What was the intermediate form between Pelagic-lobe finned fishes (ex: Osteolepiform) and Ichthyostega and when did it live?
Tiktaalik, it had fins that could move it around on land.  It lived 375 Mya (Devonian)
How did Emma differ from D in the idea of evolution.
Emma believed in divind creation. She was into Christian Salvationsim.
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