Unit 7 Flashcards
Evolution
Change in the gene pool of a population over time
- All living beings are from the same source
- Change over time
What are the four mechanisms of Evolution? (4)
- Natural Selection
- Mutation
- Genetic Drift
- Gene Flow
What is Natural Selection and its result?
The idea that the fittest survive and have more offspring.
Result: Adaptation
1. Increasingly well suited
2. Acts on existing heritable variation *
What is Genetic Drift
random loss of alleles
example: only breeding dominate, resulting in fixation
Fixation
Where one allele goes to 100%
What are the two examples of the Genetic Drift?
- Bottle Neck Effect
- Founder Effect
What is the bottle neck effect
When a disaster causes reduction of genes
What is the founder effect
When a sample of alleles moves to a different area to reproduce, excluding other alleles
What population is Genetic Drift relevant to?
Small populations
What is fitness depended on? (2)
- Survival
- Mate ability
Stabilizing Selection
Where the intermediate (mild form) of the trait is the fittest
Disruptive Selection
Where both* extremes of the trait is the fittest
Directional selection?
Where either* one of the extremes are the fittest
What is Gene flow?
where a movement of one gene to another population
Allele Frequency?
How common an allele is in a population
How do you calculate the percentage of an allele?
(Allele Frequency) = {(#of alleles)/(total number of copies of gene in population)}
What is population genetics
the study of allele frequencies in a population and how they change
Gene Pool
All copies of all genes in a population
Microevolution
small changes in a population, which is the smallest unit for evolution
Macroevolution
Large changes involving multiple populations
What does the Hardy-Weinberg Equation used for?
It is to make a general approximation of allele frequencies
What does the Hardy-Weinberg Equation assume? (5)
- No mutation
- Random mating
- No gene flow
- Large population
- No natural selection
i.e.
1. Stable allele frequency
2. No Evolution
what is the Hardy-Weinberg Equation
(p+q)^2
p+q = 1
P^2 = homo Dominant
2pq = hetero Dominant
q^2 = homo recessive
What are the four
ways for the evidence of evolution?
- Structural - Morphology
- Molecular - DNA
- Observation - fossils
- Biogeographical evidence
Carbon 14
(neutron) + (Nitrogen Isotope) = (carbon 14) + (Hydrogen Isotope)
Carbon 14 decay?
⁶C₁₄ → ₇N₁₄ + e⁻ + νe
happens when you croak
What does Carbon 14 do?
we can determine the age of fossils
What are the three different categories of proof of evolution?
- Structural
- Molecular
- Observations
Embryology
a branch of biology dealing with embryos and their development
Homologous features
similar physical features in organisms that share a common ancestor, but the features serve completely different functions, like an arm and a fin of a fish
vestigial structures
a physical feature of an organism that has lost most or all of its original function through evolution - like our tail bone
analogous features
similar traits in different species that have different anatomies but serve the same function
convergent evolution
Where unrelated species develop similar traits due to the similar environments
Biogeography
the study of how species and ecosystems are distributed across the Earth’s surface and through time
strata
The layer in the rocks where they find fossils
Taxonomy
The science of classifying organisms
biodiversity
variety on earth
topology
the way in which constiuent traits are related or arranged
Reproduction Isolation
Two species cannot mate due to obstacles
What are the two types of reproductive isolation?
Pre-zygot Isolation
Post-zygot Isolation
Pre-Zygot Isolation components
- Temporal/Habitat Isolation
- Behavioral isolation
- Mechanical isolation
Post Zygot Isolation components
- Zygote Mortality
- Hybrid Mortality
- Hybrid Sterility (kids can’t have kids)
Dispersal
the movement of organisms from one location to another, such as from their birthplace to a breeding site
Species
Animals that can:
1. interbreed
2. Fertile offspring
Hybrid
an organism that is the offspring of two different species or subspecies
speciation
differences in a species that cause multiple species to be borne
Allopatric Speciation
Speciation due to geographical distance
Sympatric Speciation
Speciation in the same geographical area
polyploidy
too many haploids in a plant, but it still works
Asexual Reproduction
the production of zygotes due to same sexes reproducing
Sexual Reproduction
the production of zygotes due to different sexes reproducing
what does the Genetic Diversity look like in sexual and Asexual reproduction ?
Sexual - High
Asexual - Low
When was Earth born?
4.6byu
when did life originate?
3.9-3.5 (byu)
When was the first Fossil evidence found?
3.5 byu
What are the four hypothesis for how life started?
- Oparin-Halden Hypothesis
- Metabolism First Hypothesis
- RNA world
- Space
Primordial Soup
a solution rich in organic compounds in the primitive oceans of the earth, from which life is hypothesized to have originated
How did monomers group into polymers in early earth?
There were neither enzymes or other catalysts, so it was made spontaneouesly
What are RNA’s capabilities?
It can
1. Store genetic information like DNA
2. Catalyze reactions like PROTEIN
3. Do its normal job - make proteins
4. Turns transcription on and off, controlling life
Grabber RNA
In early earth, an RNA grabbed onto another RNA, building a more complex world
ribosome
controls whether a mRNA turns into a protein
SRP
sends proteins where they are needed while it is being formed, and at their destination is formed completely
early version may have emerged helping to build a cytoskeleton of a cell
Gene Manipulating RNA
Chops of unwanted parts of a mRNA and glues the rest back together, speeding up evolution
Alternative Splicing
A re-mix of RNA to make more proteins, speeding up evolution
What was the conclusion of the Miller-Urey Experiment
- It attempted to make early earth simulations, but ended up being inaccurate
- It produced Amino Acids
Genetic Diversity
Variety of genes in a given species
Species Diversity
Number of species in a given area
Adaptative radiation
- A single species moves to an island
- They adapt to the island’s niches
artificial selection
where humans directly influence the genetic makeup
when a species become extinct, the niche it occupied becomes ______________ to other species.
available
Natural Selection acts on______, but evolution acts on ________________.
individuals
populations
common ancestor node
a node in a tree that is an ancestor of two or more other nodes
out group
least related to other groups
the more diversity, the _______________ ____________ of ___________.
higher chance of survival
sexual selection
when certain traits are more attractive for mating ig…
punctuated equilibrium
the idea that evolution (change) occurs in spurts instead of following the slow, but steady path
gradualism
the theory that species change over time through small, incremental changes
adaptive radiation
the rapid diversification of a single ancestral species into a multitude of new forms, each adapted to occupy a different ecological niche
flora
study of the distribution of plants in the environment
fauna
study of the distribution of animals in the environment
cladogram vs. Phylogenetic tree
cladogram - shows time in evolution
phylogenetic tree - does NOT show time in evolution
clade
different groups in a phylogenetic tree
nodes
common ancestors
root
most common ancestor of ALL members
What are three evidences of common ancestors of eukaryotes?
- membrane bound organelles
- linear chromosomes
- introns
adaptive radiation
the evolution of organisms into separate species that occupy different ecological niches
Hybrid breakdown
when species can replicate and have fertile children, but the hybrid becomes more and more weak
polyploidy
replication of MORE chromosomes, causing speciation (sympatric speciation)
