5.4.1
Define Evolution
-the cumulative change in the heritable characteristics/gene pool of a population
-result of mutations, natural selection, and genetic drift
D.1.1
Describe four processes needed for the spontaneous origin of life on earth
1. non-living synthesis of simple organic molecules
2. the assembly of these molecules into polymers
3. origin of self-replicating molecules that made inheritance possible
4. packaging of these molecules into membranes with an internal chemistry different
D.1.2
Outline the experiments of Miller and Urey into the origin of organic molecules
-showed that organic molecules can be formed under certain conditions after creating an apparatus to test ideas
-experiment has been repeated
-1970: meteorite has 7 amino acids not found on Earth
D.1.3
State that comets may have delivered organic compounds to Earth
-comets contain a large amount of more complex organic compounds
D.1.4
Discuss possible locations where conditions would have allowed the synthesis of organic compounds
-deep-sea hydrothermal vents
-volcanoes
-extraterrestrial locations
-represents accessible energy and raw materials needed for creation of monomer and assembly of polymers
D.1.5
Outline 2 properties of RNA that would have allowed it to play a role in the origin of life
-self-replication (original strand is template)
-catalytic activities (RNA enzymes are called ribozymes)
D.1.6
State that living cells may have been preceded by protobionts, with an internal chemistry different from their surrounding
-Protobionts: organisms that are (controversially) considered to have been the precursors to prokaryotic cells
-could have spontaneously formed early in Earth's development
-Ex. coacervates and microspheres
D.1.7
Outline the contribution of prokaryotes to the creation of an oxygen-rich atmosphere
-Used to perform anaerobic respiration
-Changes allowed prokaryotes to use water instead of hydrogen sulfide which allowed them to reproduce rapidly, causing the amount of oxygen in the air to increase
D.1.8
Discuss the endosymbiotic theory for the origin of eukaryotes
-mitochondria and chloroplasts were taken in by endocytosis and kept alive
-evidence: they grow and divide like cells, have a naked loop of DNA, have double membrane, synthesize proteins
5.4.2
Outline the evidence for evolution provided by the fossil record, selective breeding of domesticated animals, and homologous structures
-Fossil Record: provides snapshots of the past that illustrate evolutionary change over the past 4 bil years
-Selective breeding: man-made evolution based on particular traits
-Homologous Structures: same structure, different functions (derived from commo
5.4.3
State that populations tend to produce more offspring than the environment can support
-production of many offspring increases likelihood of genes being passed on by survivors
5.4.5
State that members of a species show variation
-size
-pigmentation
-other
5.4.6
Explain how sexual reproduction promotes variation in a species
-meiosis involves separating homologous pairs of chromosomes
-mixing of gametes leads to further variation
5.4.4
Explain that the consequence of the potential overproduction of offspring is a struggle for survival
-overproduction leads to competition
-best-suited individuals survive
(natural selection)
5.4.7
Explain how natural selection leads to evolution
-individuals best adapted will have increased levels of survival and reproduction
-more of these organisms will survive and reproduce and those without favorable traits will decline
5.4.8
Explain 2 examples of evolution in response to environmental change; one must be antibiotic resistance in bacteria
-Dinosaurs: couldn't deal with cold climate; warm blooded mammals took their place
-Bacteria: bacteria have developed resistance since antibiotics became widespread
D.2.1
Define allele frequency and gene pool
Allele frequency: a measure of the relative frequency of an allele on a genetic locus
Gene pool: the complete set of unique alleles in a species or population
D.2.2
State that evolution involves a change in allele frequency in a population's gene pool over a number of generations
-organisms with beneficial traits reproduce more than those without
-the allele frequency for the favorable trait is increased
D.2.3
Discuss the definition of the term species
biological species concept defines a species as:
-a group of potentially interbreeding populations, with a common gene pool that is reproductively isolated from other populations
D.2.4
Describe 3 examples of barriers between gene pools
D.2.6
Compare allopatric and sympatric speciation
-Speciation: the formation of new species from an existing population
-Allopatric speciation: occurs when a physical barrier separates a species
-Sympatric speciation: occurs in the same geographical area
D.2.6
Compare allopatric and sympatric speciation
-Geographical isolation: mountains, oceans, etc.
-Temporal isolation: times of day/year
-Behavioral isolation: breeding behavior
-Hybrid infertility: offspring of certain hybrids are infertile and therefore eliminated from the gene pool (does not lead to
D.2.5
Explain how polyploidy can contribute to speciation
A polyploid organism contains more than 2 sets of chromosomes
-triploids and diploids cannot produce fertile offspring which means no speciation
D.2.7
Outline the process of adaptive radiation
Adaptive radiation: initially similar organisms from a common ancestor becoming different as they adaspt to new environments
(this is divergent evolution)
D.2.8
Compare convergent and divergent evolution
Divergent: related species becoming dissimilar
Convergent: unrealted species become similar in appearance
D.2.10
Describe one example of transient polymorphism
polymorphism: "many forms" - an allele has two different forms
-transient polymorphism: selecting for one allele
-balanced polymorphism: selecting for heterozygote
-industrial melanism: darkness acquired by a population in a soot-darkened environment in a
D.2.11
Describe sickle-cell anemia as an example of balanced polymorphism
-Homozygous FOR sickle-cell anemia (sca) causes sca and resistance to malaria
-heterozygous for sca causes some sickled cells and resistance to malaria (this is what balanced polymorphism is selecting for!)
-Homozygous dominant causes normal hemoglobin bu
Hardy-Weinberg Principle/Equilibrium/Model/Theorem/Law
states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences
Assumptions of Hardy-Weinberg Equilibrium
1. infinite population size
2. no allele flow
3. no mutations
4. there is random mating
5. no natural selection