Evolution 131 Flashcards
T/F: Theories of evolution are generally a very old science
FALSE
Explain original theory by Plato and Aristotle
“Cyclical stasis” - everything moved around in a cycle that repeated itself but in a “progressive way”
What is one of the major ideals that prevent the forward movement of the science of evolution
The book of genesis/religion
Around what time did evolution start getting accepted?
1700s
When was Darwin’s model presented and when was it integrated?
1860s
1930s
What was Lamark’s evo therory? Give an example
Scala Naturae: organisms start at the bottom of a “escalator” and continuously take steps towards a more perfect form. There were multiple episodes of special creation
-Example- fish all become mammals and start at the same place but not all fish were related and created independently
What was Cuvier’s evo theory?
Natural Theology ->Static Perfected Machines: organisms were built as adapted machines to their environment. Only way to get something new is to wipe out the existing and something new will be created in its place.
What was the ideal of Natural Theology?
the world was a “perfectly tuned machine” with everything in harmony with each other, no competition, no evolution
“A place for everything and everything in it’s place”
What was Darwin’s evo theory?
“natural selection” - world was in harsh competitive equilibrium. race of adaptation leads to both extinction and speciation
What was wrong with Darwin’s model at the time
It was not proveable at the time and went against the major church teaching which was powerful at the time
______ is the central organizing concept in bio.
Evolution
Evolution is based on the principles of what? and What does it operate on?
Genealogical continuity, variation, sorting by natural process
-all this operates on spatial and temporal scales to produce diversity and pattern.
Generally how would evolution be static under Darwin’s theory?
if a beneficial variation gets lost in the next generations
Pre-mendelian genetics assumed that features of parents were ____ in offspring leading to ____ of certain traits
- blended
- dilution
Mendel showed that genes _________ across generations
retained their IDS across generation
novel phenotypes arise through what?
- recombination (meisos-gametosis- alleles)
- mutation
T/F: DNA is an unstable molecule subject to many factors
FALSE - it is relatively stable
How do mutations come about (in respect to DNA and nucelotide base-pairs)
errors in “coding’ aren’t caught and translated into genetic material (base subs, base insertions/deletions, inversions, duplications)
What do mutations do in respect to chromosomes/loci?
moves gene segments or single/multiple loci within the chromosomes
What does it mean that mutations aren’t truly random?
some loci have more of chance to have mutations but still has no significant impact
Mutations are random with respect to _____
adaptation
T/F: Most mutations are neutral/deleterious and rarely result with benefit
True!
How does the chance of a beneficial mutation occurring increase?
build up of neutral/nearly-neutral mutations acted on by GSE over time
What is gametogensis?
Process of meiosis where diplod cells divide to produce haploid gametes
What mixes up existing genetic variation/the existing gene pool of variation?
recombination (sex)
- independent assortment
- crossing over
In reproduction, what is driving recombination forces produce the immense variation of gentotypes among gametes?
- crossovers
- independent assortment of maternal/paternal chromatids
Fusion of gemetes of different individuals further increases ______
genetic diversity
Where does recombination get its genetic info?
the pool of existing alleles (including conserved mutations)
What accounts for most of the genetic diversity of a population at a given time?
Recombination
What is the source of genetic variation?
MUTATIONS
How were mutations experimentally used?
to define gene actions and where they reside
What are the “classical” and “balanced” school of population genetic theory?
check handout
According to experiments that support the “balanced” school what percent of loci from studied organisms had 2 or more allelic forms? They were heterozygous from what percent of their loci?
20-85%
5-20%
What does the HW equilibrium tell us?
What the predicted frequencies of genes will be in the next generation
What does HW prove in respect to recombination?
sexual reproduction does not constantly drive evolution (alter genotype frequencies)
T/F: HW shows that no real evolution is going on
True
What are the requirements for HW rule?
- Pop size is infinite
- equal sex ratios w/ random mating (no sexual selection)
- no gene flow (immigration/emmigration of genotypes
- no natural selection
- no mutation or its canceled out
HW rules states that genotype freq will reach equilibrium state in _________
a single generation