Evolution2 Flashcards

Terms Definitions
Linneaus
taxonomy
gregor mendel
genetics/mutations
5 Major Extinctions
OrdovicianDevonianPermianTriassicCretaceous
Co-Evolution
-phloem-feeding insects (aphids)
-reduced genome (bacteria.. helps aphids.. only 100 genes)
-plasmids of a.a. biosynthesis (in bacteria, used by aphid)
bacteria makes..
trpEG (rate limiting gene)
leucine
 
-both increase host's ability to synthesize a.a. 16-20 times
 
**every host speciation event results in a bacterial speciation event
synapomorphy
homologous similarities among organizms because of a shared immediate ancestry
Chromosomal Alteration
INVERSION
-Drosophila...
-Old World spp. have cline (change in freq /w lat) with series of inversions (due to adaptation?)
New World... Chile 1978 and Washington 1982 both had same set of 19 inversions...
 
-similar clines in both new populations
-same as Old World
-What genes are found in the inversions???
-inbreeding exps allowed to see homozygous form
-affects body size (small body for hot dry areas and large body for wet cooler areas)
 
POLYPLOIDY
-extra copies of entire chromosomes
-common in plants
-rare in animals (earthworms can self fertilize, some asexual animals such as goldfish, moths, salamanders)
-can lead to instant speciation
 
Plant parent...
-mutation causes production of diploid gametes... causes 4n from 2n gametes in first generation
-can continue to produce 4n individuals, if mates with only 2n
-won't work if self-fertilizes, mates with 4n sibling, or backcrosses to parent.
 
if backcross.... produces 3n which is sterile
DNA
Deoxyribonucleic acid. The genetic material consisting of a complex molecule whose base structure directs the synthesis of proteins.
neogene epochs
miocene, pliocene, plestocene, holocene
Inheritance
condition for natural selection; offspring inherit traits from their parents which is a mix of both parents' traits
MHC
major histocompatibility complex - large gene family found in vertebrates that has to do with immunity
Homonids
human being with their ancestors
radiation
diversification of population or species
stabilizing selection
natural selection that favors intermediate variants by acting against extreme phenotypes
3 Domains
Bacteria - ProkaryoticArhcea - ProkaryoticEukarya - Eukaryotic
Darwin
Developed basic concepts and the theory of evolution. However he did not publish them until Alfred Wallace came up with similar theorys.Then in 1859 Darwin published.
Apomorphy
derived character state in 1+ descendents
How many separate species, both extant and extinct, are depicted in this tree?a. 6b. 4c. 2d. 3e. 5
A
Extinction
The disappearance of an entire species
Dobzhansky-Muller
model of evolution of genetic incompatibility - selective pressure against a combination of alleles in the heterozygous state
Law
A DESCRIPTIVE GENERALIZATION about how some aspect of the natural world behaves under stated circumstances
gradualism
differences b/w organisms have evolved incrementally, by small steps through intermediate forms
Embryo
Organism's early prebirth stage of development
Primates
Mammals that include humans, apes, and monkeys.
premating behavior
no attraction between males and females
Secondary contact
After the allopatric speciation, the geographic barrier is removed, and the two populations re-establish contact.
Gene Flow
genetic additions or subtractions from a population, resulting from the movement of fertile individuals of gametes
Phenotypic variation reflecting environment
Examples:
1. Genetically similar plants under different wavelengths of light grow to different heights
2. Sex ratio in reptiles depend on temperature
polymorphism
loss of variety across the entire genome over time
Which of these evolutionary agents is most consistent at causing populations to become better suited to their environments over the course of generations?a. Gene flowb. Mutationc. Natural selectiond. Non-random matinge. Genetic drift
C
Evolution
Change in allele frequencies of a population over time.
species selection
speciation = birth, extinction = death
loss of function mutation
-problem with terminology...
 
-not all mutations result in loss of function
-not all mutations occur in coding regions
-regulatory proteins can turn on functions (ie. suppressors)
How many eds of Origin where there?
6
Population
group of indviduals within the same species that can interbreed and produce fertile offspring
Variation
The variety of organisms found within the same species.
 
What evidence of evolution is: there are similarities in structure among the early stages of fish, birds and humans
embryology
survival of the fittest
(natural selection)
organisms that are most adapted to their environment survive
hybrid inviability (postmating)
hybrid fails to reach sexual maturity
In Africa, the maintenance of the sickle-cell allele in human population is attributed to what?
stabilizing selection
Fosil Record
Reaveals species that are extinct we are able to see how animals evolved
Vestigial Organ
organ that serves no useful function in an organism
Disruptive selection
Favors individuals at both extremes of the phenotypic range
 
Difficulties in Tree Building2)
Dealing with Homoplasies (Homoplay common)-homoplasy is common and a data set may yield several different phylogenetic estimates that are equally good
Clade
Any taxon that consists of all the evolutionary descendants of a common ancestor
ecomorph colonization
one ecomorph is not colonizing new island and then radiatin - islands are colonized by different forms
r- K
r-K selection has been applied to discuss life history variation within species or between species. THey are extremes.
 
r-Strategist
-small
-rapid reproduction
-short-lived
-large number of offpsring
-semelparous
-unstable environments
-weak competitor
-precocial young
 
K
-large
-slow repreoduction
-long-lived-
-few offspring
-iteroparous
-stable environments
-good competitor
-altricial young
What is a pseudo-gene?
A gene that is inactive
What is Disruptive selection?
Selection against intermediate form and in favor of both.Ex would be the meduim babies would die.
darwin's view of evolution
origin of life, anagenesis, cladogenesis
all genes in a population is called
gene pool
Genus & Species 17th century
John Ray, 17th Century
-Reproductively isolated groups into 'species'
-Some species shared similarities called 'genus'
gene frequency
how common a gene in in a population
genetic drift
the process of change in the gene frequencies of a population from one generation to the next due to statistical phenomena in which purely chance events determine which alleles (variants of a gene) within a reproductive population will be carried forward while others disappear
What's the difference between haplotype bias and linkage disequilibrium?
Haplotype bias means that certain genotypes at loci on the same chromosome tend to be associated with one another more frequently than other genotypes.  For instance, the AB genotype might be more common than aB, Ab, or ab and it might be because A and B, when together, have higher fitness than the other genotypes. Linkage disequilibrium is the end product of haplotype bias because the ABAB genotype occurs more frequently than expected. Neither locus will be at HW equilibrium, hence linkage disequilibrium.
A biologist is studying how courtship patterns of different species affect their inability to interbreed.  This biologist would be studying which of the following?
A. habitat isolation
B. mechanical isolation
C. gamete isolation
D. behavioral isolati
 
 
 
D. behavioral isolation
Reverse Mutations
When a species begins to form traits that belonged to their ancestors, again, for whatever reason
Transposable elements (phylogenomics)
HGT - horizontal gene transfer - lateral gene transfer
-between individuals.. not vertical transfer
 
Genome Size
-fruit fly 180million bp
-ameoba 670billion bp.. mostly junk
-human  billion bp.. 1.2% coding, 44$ transposable elements (genetic parasites)
 
Transposable elements replicate themselves... do not need a coding region
-help "move" DNA
-flanking regions (encode enzymes for moving, repetitive DNA)
Class 1 (use RNA intermediate, reverse transcriptase), and clas II, (DNA to DNA)
 
Retrotransposons (class I)
1..DNA of the mobile element is transcribed into RNA
2.RNA is reverse transcribed into cDNA, which then inserts into the recipient site
 
Conservative Transposition (class II)
-element moves from one site to another
-cut and paste
-element moves from one site to another
 
Replicative Transpositon (copy and paste)
0the transposable element is copied, and one copy remains at the original site while the other inserts itself at a new site
-like jumping genes with corn
-potential to duplicate large chunks
 
Transposons in bacteria
-mobile elements carry the transposase gene
-enzyme cuts the trasnposon from the flanking DNA and inserts it into the target DNA site
-may carry antibiotic resistance genes
-ie. ampicillin and tetracycline (can transfer resistance)
 
IMPACT of Transposable Elements
-can turn genes on/off through interference
If transposable elements are parasitizing the genome, how can natural selection slow the spread?
-preventing spread... eukaryotes: methylationa add methyl group)
-positive impact of transposable elemtns..
-antibiotic resistance
-exon shuffling
What is polyploid?
3 or more sets of DNAAutopolyploidy- doubling chromosome number of speciesAllopolyploidy- Hybrid of 2 species
Bufon
came up with the idea of a common ancestor in 1766. said that environmental conditions change species
Muller's ratchet predicts that asexual pops will
accumulate deleterious mutations faster than sexual pops
The steps in Darwin's theory are:
overproduction, struggle for existence, variation, natural selection
Give an example of directional selection.
an increase in antibiotic-resistent bacteria
What are point mutations?
changes in dna base sequence pairs that cause changes in aa sequence
1. base pair substitution
2. frame shift substitutions
Red Queen Hypothesis
Each species has to run (evolve) as fast as possible just to stay in the same place (survive) because its competitors, predators and parasites also continue to evolve
Who was the most aggressive challenger of D? What did he do? Who did he support?
Owen, comparative anatomist/surgeon, Church
What is the Hardy-Weinberg principle, and what are the 5 factors?
Allele frequencies will remain constant unless one or more factors are in play. The 5 factors are random mating, no mutations, no natural selection, no movement, and large population.
rate of evolution: Gradualism
evolution proceeds at a slow and steadt reate
List two definitions of a gene.
1. genes/alleles defined by phenotypes they produced,
defined as units of inheritance:
e.g. "Eye color gene" (red eye allele, white eye allele)
 
2. can also define genes/alleles at the molecular level,
defined in terms of genetic basis as units of transcription
How did the voyage of Beagle influence Darwin?
Biogeography: South America; Galapagos-Saw finches from one area were different than finches in another area, had same ancestors.Fossils:Geology: Documented evidence for the phenomenon mentioned by Lyell's book
How old did people used to believe the Earth was?
10,000 years old
Jean B Lamarck did what?
He Reconized that living thigns change over time and adapt to their surroundings.
examining three ways of mass extinction
clade and bloc are selective while random is probabilistic. Each would present a different signature in the fossil record.
One of the most important observations made by Darwin on his trip around the world was:
A. species change from place to place throughout time
B. species have remained constant over time in some places but not in others
C. species have remained constant
 
 
A. species change from place to place throughout time
What effect did the native humans on the Galapagos have on Darwin? What were they called?
They were called the Fuegians.
 
They appeared different than people as Darwin knew them. He thought they seemed less developed and made him think that people may have slowly changed over time (like the earth's crust)
two common characterisics to greek origins of life
- resulted from generative powers of nature (not actions of god- they were nonteleological (no underlying design or goal)
Explain how when looking across the range of one species, continuous phenotypes might give the impression of existence of discrete phenotypes
You could be observing a polytypic triat.
 
Geographically, in two separate locations you see what looks like discrete phenotypes. However if you look in the intergrade zones (between the discrete areas) you may see intermediate phenotypes. 
how do discrete traits differ from quantitative traits
1. discrete traits are determined by small numbers of loci (usually one)2. for discrete traits it is possible to assign phenotypes into easily identified and distinct categories
Who was D's wife? When did he get married? How many kids did he have?
Emma Wedgwood. Cousin. 1842. 9 kids.
What are the 3 basic points of Darwin's theory of evolution?
In nature, there is a struggle for existence, survival of the fittest, and descent with modification.
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