l Flashcards
our solar system was formed by the gravitational collapse of a giant interstellar cloud.
nebular theory
organic compounds could be made by passing an electric current to simulate lightning
miller urey
amino acids brought by asteroid impact
meteorite hyp
amino acids are building blocks of
protein
2 hyp on formation of cell memberane
iron sulfide, lipid memberane
biological molecules combined in chimney like ocean floor things
iron sulfide
lipid molecules formed lipsomes
lipid membrane
rna before dna evidence
ribozymes are rna molecuels that can replicate self, dna cant without enzymes
charectoristics of life
Cellular organization, the ability to reproduce, growth & development, energy use, homeostasis, response to their environment, and the ability to adapt.
domainsof life
Bacteria - prokaryotic; single-celled;
Archaea - prokaryotic; single-celled;
Eukaryota - eukaryotic (have a nucleus); can be single-celled or multicellular;
What organisms were the first photosynthetic organisms that added oxygen to the atmosphere?
cyanobacteria
one organism lives within another ones body, both benefit
endosymbiosis
eukaryotes arose from single celled prokaryote anscester thru isolation of metabolic functions
autogenous theory
Describe how the evolution of sexual reproduction led to increased diversity and variation.
offspring could inherit diff traits from parents than sibling did
Explain how there is evidence for evolution in biogeography
The global distribution of organisms and the unique features of island species reflect evolution and geological change.
the measure of an organism’s ability to survive and produce offspring relative to other members of the population (reproduction = winning!)
fitness
the ability of a trait to be passed from one generation to the next through reproduction
heritability
- a group of organisms of the same species living in the same geographical area at the same time.
population
a collection of alleles (different types of a gene) found in all of the individuals of a population
gene pool
What observations contributed to Darwin’s proposed mechanism for natural selection?
ossil observations (described in the above section)
#2. Variations amongst populations (like Galapagos tortoises that live in areas with tall plants having longer necks and legs)… I’ve included a picture from the slides to remind you of what we were learning about at the time when we took these journal notes.
#3. Some variations appeared more helpful than others, and adaptations allow a species to better survive and reproduce in its environment (adaptations can lead to genetic change in a population)
#4. Variation in domesticated plants and animals pointed to artificial selection as a process where humans are selecting for traits
is the process by which organisms with favorable traits/variations survive and produce more offspring than less well-adapted individuals.
natural selection
What are the four main principles of the theory of natural selection? Descr
Variation - genetic differences in the population’s gene pool must be present for some traits to be selected for more frequently compared to other traits. The traits have to be heritable so that offspring are produced that carry the same genetic trait that was selected for in their parents/ancestors. The traits cannot be the types that are just acquired through life.
Overproduction - While having many offspring raises the chance that some will survive, it also results in competition between offspring for resources.
Adaptation - the trait that is inherited must allow the individual to survive and reproduce better than individuals that do not have that trait
Descent with modification - Over time, the organisms with adaptations will produce offspring that are also adapted. More individuals in the population will have the trait in every following generation, as long as the selective pressure (like environment for natural selection) continues to remain beneficial for that trait.
Natural selection may not produce a “perfectly-engineered” trait. Why not?
lack of genetic variation
What is the difference between directional selection, stabilizing selection, and diversifying selection? Give specific examples to help you explain each.
directional selection- one of the extremes is favored , 1 direction, 2 humps, like a mountain range
stabilizing selection- the non extreme is favored, mean above second hump, skinny and in the hump otherwise.
diversifying selection- both extremes are favored, 3 hump
observable changes in population trait frequencies
microevolution
normal distribution=
not going thru natural selection
intersexual
choosiness
intrasexual
compeition
How can variations be introduced to a gene pool?
Reproduction can introduce new gene combinations into a population
Explain gene flow and give a specific example.
Movement of genes from one population to another
A sheep from one herd mating with a sheep from another
Explain genetic drift and give a specific example.
Change in allele frequencies due to chance (can cause severe problems)
The bottleneck effect (when one population size is severely decreased)
The bottleneck effect and the founder’s effect both influence genetic drift. Describe each of these.
bottleneck effect - genetic drift after a population is greatly reduced in size
Founders effect genetic drift after some individuals colonize a new area
The formation and distinct species in the course of evolution
speciation
What are variations in traits? (and What is our key idea from our giraffe notes related to this?)
variation in traits is referring to the variety of phenotypes we can see in a population (short, tall, etc.
What are the sources of genetic variation? Se
Sexual recombination (which provides new gene combinations) and mutations (which provide new genes through changes in DNA) are the sources of variation.
do individauls adapt to envoirment
no, populations do
- isolation between populations due to barriers related to time, such as differences in mating periods or differences in the time of day that individuals are most active, etc. The book gives examples of pine trees that shed pollen during different seasons.
temporal isolation
linneaus
binomial nomenclature
buffon
species share anscestors
erasmus darwin
More complex forms developed from less complex forms
lamarck
envoirmentalchanges lead to use of disuse of structures
lyell
Credited for uniformitarianism - every form of rock in sedimentary rock was deemed by the uniform laying down of sediment that still occurs today
darwin
Son of erasmus
Natural selection is the mechanism by which individuals that have inherited beneficial adaptations produce more off spring on average than do other individuals
Compare and contrast the ideas of Lamarck and Darwin
Darwin thought that the desires of animals have nothing to do with how they evolve, changes in an organism’s lifetime do not affect the traits passed on to its children
phylogentic trees
represent geneic relationships and linageas, branch length represent time
cladogram
based on differenfces in phenotypic traits, NOT GENETIC, branch no show time it shows series of ancestors
show same evolutionary relatioship between taxa
tree and gram
