Studied by 49 peopleTags & Description
Uniformitarianism
the rates of change that we see today have been the same through earth history . processes of change are uniform
Catastrophism
the world came about very quick through sudden chromatin changes - great flood, in 7 days -exclusive idea until 1800s
Lamarckism
(disproven theory) inheritance of acquired traits= changes to an organism during a lifetime are passed on its offspring
Natural selection
process that promotes the maintenance and spread of traits that enhance survival and fecundit
individuals vary heritable component to variation individuals with certain attributes survive and/or reproduce better than others
evolution by natural selection consist of?
Adaptation
-attunement to the environment -a trait that increases fitness in a particular environment -only get from natural selection
purifying selection
selection for the current phenotype (keeping the phenotype exactly the same)
disruptive selection
selection for two different allele states
directional selection
-selection away from the current phenotype -replacement of one allele with another
hardy weinburg model is?
to calculate allele frequencies in the next generation -what happens to alleles in the next generation
key assumptions of hardy weinburg equilibrium
No natural selection on allele No genetic drift Random mating Also no migration of allele for another population
genetic drift
-evolution due to chance events in small populations -change in allele frequency due to sampling error
neutral theory
most evolutionary change in dna sequences (sequence evolution) is due to genetic drift of mutant alleles that are selectively neutral (Motoo Kimura)
synonymous mutation
when a change in nucleotide sequences doesn't change amino acid sequence
non-synonymous mutation
when a change in nucleotide does change the amino acid sequence
primordial soul model
life began from a series of chemical reactions in water on earth's surface triggered by an external energy source such as lightning strike or ultraviolet (UV) light Hypothesis
primordial soup model hypothesis
Spontaneous appearance of organic molecules Emergent properties- resulting in more complex macromolecules An evolutionary selection occurred for self replication and membrane compartmentalization
RNA world hypothesis
life on earth began with a simple RNA molecule that could copy itself
-RNA can serve as both a genetic code and a folded structure that enables enzymatic function
why did RNA world start
chimera hypothesis
In biology, a chimera is an organism containing a mixture of genetic material from 2 or more (usually distant related) species -an achaean and bacteria fused to form one
endosymbiont hypothesis
-mitochondria lived inside primitive eukaryotes and evolved to become co dependent -may have started as a parasite or undigested food
complex life evolved without mitochondria
endosymbiont hypothesis
complexity was not possible without mitochondria
chimera hypothesis
why was the evolution of eukaryotic/mitochondria significant?
Eukaryotes escaped the need for extreme efficiency and replication speed
the organization of the eukaryotic cell
Mitochondrion lost 99% of its genome Nucleus gained tens of thousands of genes
modern eukaryotic cell
mitochondrial component- metabolic and biosynthesis functions
what are the archaeon & bacterial genomes in eukaryotes?
nuclear DNA(archaeon) Mitochondrial DNA- (bacterial )
introns
the result of insertion of mitochondrial DNA into nuclear DNA
two adaptations in response to intron problem
spliceosome & nuclear membrane
spliceosome
molecular system that cuts out introns before translation (already existed in bacteria
nuclear membrane
needed to physically separate transcription and translation
mitonuclear coadaptation hypothesis
selection for mitonuclear coadaptation is only possible if there is no heteroplasmy
mitonuclear coadaptation
The coordination of function by the products if the mitochondrial genome and the nuclear genome to achieve oxidative phosphorylation,maintained by coevolution
genomic conflict hypothesis
avoiding heteroplasmy is necessary to avoid genomic conflict among mitochondria (selecting for faster replication speed)
genomic conflict
A conflict of interest within an organism wherein one or a set of genes have phenotypic effects that promote their own transmission to the detriment of the transmission of their genes that reside in the same genome
gene level selection hypothesis
Each gene promotes its own spread in the population Natural selection acts at the level of the gene
selfish gene
does not harm other genes
outlaw genes
directly harm other genes
genomic conflict
contest among genes
the paradox of sex (two fold cost of sex)
lose 50% of reproductive advantage through asexual reproduction -when producing sexually. female is only 1/2 related to offspring
red queen hypothesis (adaptable genotype theory of sex)
Asexual does not produce enough and is not diverse enough to keep up with environmnetal changes Pathogen co evolution is proposed as the main driver of sex
sexual reproduction
the production of descendent individuals by combining t=genetic information from “parent” individuals
asexual reproduction
genome is copied and transmitted to descendants
advantages & disadvantages of asexual reproduction
advantages & disadvantages of sexual reproduction
-reproducing sexually, a female is only 1/2 related to offspring -cost of mate searching, sexual diseases, destruction of successful gene combinations -recombination (advantage)
antagonistic pleiotropy
when the fitness effect of a gene is both positive and negative
antagonistic pleiotropy of aging
natural selection favors genes that bestow benefits early in life even if they carry a cost late in life
How is the germline shielded from mutation?
The mitochondria of female germ cells are almost never metabolically active.
r selected species
invest more ein reproduction and less in self maintenance for survival (rat and finch) -short life, more reproduction
k selected species
invest less in reproduction and more in self maintenance for survival -long life, less reproduction
2 broad methods for constructing phylogenies
phenetics & cladistics
phenetics
method for constructing phylogenies based on the overall similarity of the organisms . total shared traits Group organisms by similarity
cladistics
method for constructing phylogenies based on shared derived characters
homology
similar by descent (inherit trait from common ancestor)
homoplasy
similar due to convergent evolution (independently evolve trait)
cladogenesis
formation of 2 or more species from an ancestral species (speciation)
anagenesis
evolutionary change within a species (lineage) over time. descent with modification (adaptation)
biological species concept
-s species sia by interbreeding population reproductively isolated from all other populations
“Good species do not hybridize”
phylogenetics species concept
-a species is any group of organisms with a unique evolutionary history as diagnosed by one or more traits -any diagnosable (difference) group is a species
proximate causation
the developmental and physiological mechanisms responsible for the trait
ultimate causation
the evolutionary forces that shape the trait
hamiltons rule
social behavior evolves under specific combinations of relatedness, benefit and cost B x R > C
eusociality
behavior pattern where some individuals do no reproduce to promote the reproduction of others
intrasexual selection
male-male competition -direct contents for access to mates -leads to the evolution of armaments
intersexual selection
female mate choice -coercing females into choice -leads to evolution of ornaments
indicator trait hypothesis
ornamental traits are honest signals of male quality -by choosing ornamental traits, female gain fitness benefits beyond attractive sons
genotype physical condition/resources
what determines male quality
mutualism
two species benefits from the activity of each other
symbiosis
two species depend on the existence of each other
coevolution
changes in the allele frequency in the genome of one species affects the allele frequencies in the genome of a second species
life on earth started
3.5 billion years ago
the big bang was
14 billion years ago
eukaryotes came about
2 billion years ago
earth was created
4.5 billion years ago
gene,group,individual are
the individual
with two mating types
you lose half of the mates
Note
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