Exam 1 Flashcards
Why is antibiotic resistance becoming more common
Bacteria and viruses can produce new generations in a short period of time - resistant strains can proliferate life very quickly
How is antibiotic resistance an example of evolution
pathogens in a population that are resistant to antibiotics are selected, evolution by natural selection occurs rapidly due to the rapid reproduction, pathogens that are resistant will survive the antibiotics and reproduce
Evolution
(1) descent with modification; change in the genetic composition of a population from generation to generation
(2) the process by which a species accumulate differences from their ancestors as they adapt to different environments over time
Alfred Russel Wallace
a British naturalist who developed a hypothesis on natural selection nearly identical to Darwin’s- submitted his ideas for publication first
What is Lamarck primarily known for?
his incorrect hypothesis of evolution
Lamarcks hypothesis of evolution
- (use and disuse) parts of the body that are used extensively become larger and stronger, while parts that aren’t used deteriorate
2.(inheritance of acquired characteristics) organisms pass modifications to their offspring
What was Lamarcks visionary recognition about?
proposed how life changes over time, evolutionary changes explain patterns in fossils and how organisms are well suited for their environments
Lamarck thought evolution happens because
organisms have an innate drive to become more complex
Georges Buffon
discovered that animals of different species could be crossbred, but their offspring were infertile
Georges Cuvier
developed paleontology (the study of fossils)
What did Cuvier infer about extinction
opposed evolution believed the boundary between strata represented a catastrophic event that destroyed species
James Hutton
proposed that earth’s geological features could be explained by gradual mechanisms
Charles Lyell
proposed that the same geological process that Hutton suggested are operating today as in the past at the same rate
Who suggested that profound change could take place through the cumulative effect of slow but continuous processes
Hutton and Lyell
How did Darwin apply the idea of gradual change to biological evolution
if a geological change results from slow continuous events, the earth must be much older than was believed
Charles Darwin
wrote The Origin of species,developed a scientific explanation for the diversity of life - concluded that all life develops over time
Darwin’s description of natural selection
explains how adaptations arise; a process in which individuals that have certain inherited traits tend to survive and reproduce at a higher rate because of their traits
Microevolution
a change in allele frequencies in a population over generations
Birds with alleles encoding large beaks surviving at a higher rate is an example of
microevolution
Macroevolution
the broad pattern of evolution above the species level
The origin of new groups of organisms such as mammals or flowering plants through a series of speciation events is an example of
Macroevolution
Gene Pool
all copies of every type of allele at every locus in all members of the population
Directional selection
shifts the overall makeup of the population by favoring variants that are at one extreme of the distribution
Disruptive selection
favors variants at both ends of the distribution
Stabilizing selection
removes extreme variants from the population and preserves intermediate types
Conditions favor one extreme of a phenotype; light mice are favored over dark mice
directional selection
conditions favor both extremes of a phenotype and select against intermediate types; light and dark mice favored only
disruptive selection
acts against both extreme phenotypes and favors intermediate; selects against light and dark mice
stabilizing selection
Natural selection vs artificial selection
Natural= nature selects variations with favorable traits better suited for an environment
Artificial= humans select and breed individuals based on selected traits
When a few individuals become isolated from a larger population, the smaller group may establish a new population whose gene pool differs from the source population
Founder effect
members of a population being blown away by a storm to a new island is an example of
The founder effect
a sudden change in the environment may drastically reduce the size of a population, alleles may become overrepresented, underrepresented or absent due to the drastic size reduction
bottleneck effect
Yellow, blue and white marbles mixed together are poured into a glass, there are now mainly blue marbles, one white and no yellow
bottleneck effect
chance events that cause allele frequencies to fluctuate unpredictably from one generation to the next, especially in small populations
genetic drift
A small wildflower population has a stable size of 10 plants, by chance only 5 plants of generation 1 produce fertile offspring, by chance again only 2 plants of generation 2 produce fertile offspring
genetic drift
related species have characteristics that are similar but have different functions
homologous structures
a human, cat, whale and bat all have the same basic skeletal structure but are used for different purposes
homologous structures
features that share similar functions but not common ancestry
analogous structures
a feature of an organism that is a historical remanent of a structure that served a function in the organism’s ancestors
vestigial structure
a human embryo having a tail before it is reabsorbed is an example of what structure
vestigial
the independent evolution of similar features in different lineages
convergent evolution
why do distantly related organisms resemble one another
convergent evolution; individuals evolve from different ancestors but adapt to similar environments in similar ways
similarities between sugar gliders and flying squirrels is an example of
convergent evolution
Types of fossils
-sedimentary rock
-mineralized organic matter
-trace fossils
-amber
-frozen soil, ice and acid bogs
most common technique of dating a fossil
radiometric dating
the time required for 50% of the parent isotope to decay
half-life
Wallaces line separates
the Asian and Australian biotic regions
Linnaeus classification system
-species
-genus
-family
-order
-class
-phylum
-kingdom
binomial nomenclature
genus, species
long periods of apparent stasis, in which a species undergoes little or no morphological change, interrupted by relatively brief periods of sudden change
punctuated equilibrium
slow and gradual changes in a species , occurs in small periodic changes in the gene pool
gradualism
the techniques used to study ___ ____ are based on the comparison of nucleotide and amino acid sequences among species
molecular evolution
first main stage to produce simple cells
the abiotic (nonliving) synthesis of small organic molecules such as amino acids and nitrogenous bases
second main stage to produce simple cells
joining of small molecules into macromolecules such as proteins and nucleic acids
third main stage to produce simple cells
packaging of molecules into protocells
fourth main stage to produce simple cells
origin of self replicating molecules that made inheritance possible
layered rocks that form when certain prokaryotes bind thin films of sediment together
stromatolites
what was earths first organism
single-celled prokaryotes that lived in the ocean
