Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
123 Cards in this Set
- Front
- Back
|
Sources of variations |
Mutations- change in nucleotide sequence; insertions, deletions, frame shifts Sexual reproduction/recombination- random fertilization, crossing over, independent assortment |
|
|
Species |
Can freely interbreed and have fertile offspring |
|
|
Population |
Same species living in a local area |
|
|
5 conditions for nonevolving populations (The opposite are causes of micro evolution) |
No mutations, random mating, no natural selection, extremely large population, no gene flow |
|
|
Microevolution |
smallest scale, Change in allele frequency In a population over generations |
|
|
3 main causes micro evolution |
1-natural selection 2- genetic drift 3- gene flow |
|
|
Genetic drift |
chance events that alter allele frequencies Is significant in Small population size Can cause allele frequencies to change at random Can lead to loss of genetic variation Can cause harmful alleles to become fixed |
|
|
Founder effect |
Occurs when few individuals become isolated from larger population Allele frequencies in the small founder population can be different from those in larger parent population |
|
|
Bottleneck effect |
Sudden drastic decrease in population because of environment , explains how we humans impact other species |
|
|
Gene flow |
Migration / movement of genes in or out, can increase or decrease fitness of population This is a very important agent of evolutionary change in modern human populations |
|
|
3 modes natural selection can alter the frequency distribution of heritable traits |
Directional selection- favors extreme end Disruptive selection- favors both extreme ends Stabilizing selection- favors intermediate variants and acts against extreme phenotypes |
|
|
Sexual selection |
Natural selection where individuals with certain inherited characteristics have more mating success Can result in sexual dimorphism-marked differences between the sexes in secondary sexual characteristics |
|
|
Darwin's term for evolution |
Descent with modification (aka natural selection) |
|
|
Who came up with theory of evolution at similar time as Darwin? |
Wallace |
|
|
Adaptation |
trait the helps you to survive |
|
|
Natural selection |
process where some individuals with favorable traits are more likely to survive and reproduce |
|
|
Unity of life |
how you relate to your environment |
|
|
Origins of species three broad observations about nature |
The unity of life, the diversity of live, and the match between organisms and their environment---resulted from descent with modification by natural selection |
|
|
Survival of the fittest |
How many surviving offspring you have; if you inherit traits that help you survive you will produce more offspring |
|
|
Extant |
opposite of extinct |
|
|
Argument for natural selection |
Like artificial selection but that happens in nature Observation 1- variation in a population traits 2- species produce many offspring but few survive |
|
|
Blind cave salimander |
Spawns from a mutation where one salamander is born blind which in this environment is an advantage. Eventually reproduces trait gets passed and becomes desirable, eventually all blind |
|
|
Why is Genetic variation important? How does it originate |
There can be no evolution or natural selection without it originates when mutation, gene duplication or other processes produce new alleles and new genes Can be produced rapidly in organisms with short generation time |
|
|
Do individuals or populations evolve? |
Populations |
|
|
Evidence that supports evolution |
Direct observation, homology, fossil records, biogeography |
|
|
Examples of direct observation of evolution |
Antibiotic resistance, pesticide resistance Introduced species- burmese pythons Experimentation will show change over time |
|
|
Homology |
similarities resulting from common ancestry Can be on a biochemical or physical level |
|
|
Comparative embryology |
reveals anatomical homologies not visible in adult organisms. For example all vertebrate embryo have post-anal tail and pharyngeal arches |
|
|
vestigial structures |
left over "stuff" from ancestors that no longer serves any importance. In humans some examples include wisdom teeth, sinuses, tail bone, the mail nipple, grasp reflex |
|
|
Criteria to produce a good Fossil |
a good fossil is buried quickly, helps if you have hard body parts, helps if there are a lot of you on the planet, helps if you were on the planet for a long time |
|
|
biogeography |
study of geographic distribution of life. distribution or organisms are influenced by many factors including continental drift |
|
|
allele |
one of a number of alternative forms of the same gene. Sometimes, different alleles can result in different observable phenotypic traits, such as different pigmentation. |
|
|
speciation |
The origin of new species from other species can start small such as changes in colors between types of fish, and get large over time such as the evolution of whales from terrestrial mammals |
|
|
macroevolution |
the broad pattern of evolution above the species level |
|
|
biological species concept |
a species is a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring, but do not reproduce with members of other such groups |
|
|
Prezygotic barriers that impede mating or hinder fertilization |
Habitat isolation, temporal isolation, behavioral isolation, mechanical isolation, and gametic isolation |
|
|
Habitat isolation |
do not have an opportunity to hook up based on geographic location Ex water vs land snake |
|
|
temporal isolation |
timing's off--species that bread at different times of day or different seasons Ex eastern spotted skunk and the western spotted skunk |
|
|
behavioral isolation |
courtship rituals to attract a mate are different from one another Ex: the blue footed boobies have a very specific ritual |
|
|
mechanical isolation |
mating is attempted but the "parts" don't fit, physically impossible |
|
|
gametic isolation |
there is mating but the gametes (sperm, egg, or pollen) are incompatible so fertilization does not occur |
|
|
Postzygotic barriers that prevent hybrid zygote from developing into viable, fertile adult |
Reduced hybrid viability, reduced hybrid fertility, hybrid breakdown |
|
|
Reduced hybrid viabilty |
The genes of the parents may interact in a way that prevents development, or environment is not suitable for offspring. This offspring doesn't make it |
|
|
Reduced hybrid fertility |
The offspring will survive and is vigorous however it is fertile and does not produce it's own offspring. Ex: mule |
|
|
Hybrid breakdown |
Some first generation hybrids are fertile and viable but breaks down with successive offspring |
|
|
If you make it past all of the prezygotic and postzygotic barriers you are: |
the same species -this classification can not be used for fossils or a-sexual beings |
|
|
speciation can take place with our without geographic isolation, each category is called |
Allopatric- with geographic isolation Sympatric- without geographic isolation *both happen slowly over considerable lengths of time |
|
|
Why does allopatric and sympatric speciation occur and what results |
Genetic drift, natural selection, restricting gene flow etc... results in 2 or more different species -need reproductive isolating mechanism |
|
|
Polyploidy |
Linked to sympatric speciation Presence of extra sets of chromosomes, accidental during cell division, happens all the time in plants, since 1800s our crops oats, cotton, wheat, potatoes, tobacco have been subject to this |
|
|
Sexual selection |
Females pick males based on looks Evidence that sympatric selection can be driven by this. As seen in Lake Victoria's 600 species of cichlids |
|
|
Rate of speication |
Successful species have been around at least 1 million years, if a species has been here for 5 million years most of it's genetic change happened in first 50,000 years. These changes can be big or small |
|
|
Punctuated equilibrium |
Hypothesis that explains period of statis punctuated by sudden change, such as after the extinction of the dinosaurs rapid change and increase in mammals |
|
|
Gradualism |
The hypothesis that life changes gradually, in contrast to punctuated equilibrium |
|
|
pre-darwin belief on the age of the earth |
Believed that the earth was young, about 6,000 years old |
|
|
Early earth physical characteristics |
Molten gaseous possibly reducing that had the reducing potential for generating life (or asteroid brought it) no oceans at the beginning and no life before oceans |
|
|
4 events of early earth |
1- Abiotic synthesis of small organic compounds 2-Join these small molecules to make macromolecule 3- package molecules into proto cells (vesicles) 4- origin of self replicating molecules (rna) |
|
|
Alternate idea to reducing life theory |
Organic compounds happened near volcanos or deep sea vents |
|
|
We have harvested amino acids from |
Meteorites |
|
|
Tramspermia |
Belief life was generated on earth by comets and asteroids |
|
|
Abiotic synthesis of macromolecules |
Rna molecules Have been produced spontaneously from simple molecules Small organic molecules polymerize |
|
|
Protocells |
Vesicles that have a lipid bilayer Clay was a big part of this Need metabolism , ability to reproduce, typical cell behavior Ex Bubbles in the water |
|
|
Vesicles-reproduction-taking on other vesicles- genetic variation-natural selection |
Evolution of vesicles |
|
|
Differences between rna and dna |
Rna- less complex, came first Dna- more stale |
|
|
Bias in geology |
We want took down some fossils more than others so they appear to be more frequent although not necessarily |
|
|
Sedementary rock |
Richest kind of fossil |
|
|
Carbon 14 |
Used for younger stuff to get the absolute age |
|
|
Radio metric isotopes |
Look up definitions |
|
|
Isotopes of uranium |
Used to find age of older fossils older than 75k years |
|
|
Cambrian age |
Huge explosion of animals during this period Where all the major animal groups we have today appear in fossil records 35-36 animal groups The first evidence of predator prey symbiotic relationship --Fueled evolution by weeding out the weaker ones |
|
|
Endosymbiotic plasmid origin |
Used to live on their own and we have evidence for this They have their own DNA A lot of other evidence for this! |
|
|
Multicellular eukaryotes |
Fungus /plants /protists Started in ocean until cambrian explosion |
|
|
Chordates |
Animals with backbones like us |
|
|
Arthropods |
Most successful animal group due to their short generation times large populations exoskeletons and the insects in this group can fly A cockroach can live for a week off the grease of a human thumbprint |
|
|
First things to move to land |
Most likely plants (that evolved from green algae) and fungi came together Mosses were first plants and they did not have vascular tissue Fungi most likely came along on roots symbiotically increasing surface area of absorption 95% of plants still contain fungi in roots successful relationship |
|
|
Tetrapods |
4 legged animals |
|
|
First modern humans |
200 thousand years ago |
|
|
Plate techtonics and its effects |
All the plate boundaries are where earthquakes sunamis have happened Things still moving Affects natural selection and extinctions Things can hit each other/slide past one another In some areas it deepens the oceans especially where sea floor is spreading Causes difference in shore line especially in shallow water where there is a lot of life Affects climate |
|
|
What kind of speciation is plate techtonics |
Allopathic |
|
|
How many mass extinctions |
5 |
|
|
Crustaeous extinction |
Caused extinction of the dinosaurs by massive asteroid hit |
|
|
Adaptive radiation |
The rapid evolution of diversely adapted species from a common ancestor May follow mass extinctions, evolution of novel characteristics, colonization of new regions Ex: Hawaiian islands |
|
|
homeitic genes |
placement in special design Hox |
|
|
Developmental genes |
Determine rate, timing, special patterns |
|
|
Hox genes |
Determine where things will be placed very important if wrong a leg could grow out of your head Type of homeotic gene |
|
|
Trend of horse evolution |
Got bigger, foot fused into one big nail |
|
|
Taxonomy |
Naming things and grouping |
|
|
Phylogeny |
Evolutionary history of a species or group of related species Ex trees |
|
|
Systematics |
Classifies organisms and determines their evolutionary relationships What group should we put this living thing I'm and how is it related to other living things? |
|
|
How people identify taxonomy phylogeny and systematics |
Are all hypothetical all different |
|
|
Endemic as it relates to biogeograhy |
When you are found in only one place in the world. Using evolution to explain biogeographic data Why are there only lemurs in madagascar? islands generally have many plants and animal species that are found no where else but are generally closely related to species from nearest mainland or neighboring island |
|
|
summary of natural selection |
process where individuals with certain heritable traits survive and reproduce in higher rates over time natural selection can increase the match between organisms and their environment if an environment changes or if individuals move to a new environment natural selection may result in adaptation to these new conditions, sometimes even giving rise to new species |
|
|
endosymbiotic theory |
mitochondria and plastids (a general term for chloroplasts and organelles) were formerly small prokaryotes that begin living within larger cells |
|
|
Homologous structures |
anatomical resemblances that represent variations on a structural theme present in a common ancestor Ex: forelimb of a mammal, looks different on the outside but same underlying structure and different uses, in a bat they can fly |
|
|
mutations |
change in nucleotide sequence of DNA causing new alleles sickle cell disease is the change of just one base in a gene called point mutation |
|
|
neutral variation |
when point mutations occur in noncoding regions and do not confer a selective advantage or disadvantage |
|
|
Hardy Weinberg equation |
p2 + 2pq + q2 = 1 p is the frequency of the "A" allele and q is the frequency of the "a" allele in the population. In the equation, p2 represents the frequency of the homozygous genotype AA, q2 represents the frequency of the homozygous genotype aa, and 2pq represents the frequency of the heterozygous genotype Aa. |
|
|
gene pool |
copies of every type of allele at every locus in all members of the population |
|
|
intersexual selection |
mate choice, individuals of one sex (usually female) are choosy in selecting their mate |
|
|
intrasexual selection |
same sex compete with each other for the "winning" of the opposite sex |
|
|
why doesn't natural selection fashion perfect organisms? |
-can only act on existing variations not ideal traits -limited by historical constraints -adaptation are often compromises -chance, natural selection, and the environment interact |
|
|
speciation |
process where one species splits into two or more species |
|
|
reproductive isolation |
existence of biological factors (barriers) that impeded members of two species from interbreeding and producing viable, fertile offspring |
|
|
4 main stages that produced simple cells |
1- Abiotic (nonliving) synthesis of small organic molecules such as amino acids and nitrogenous bases 2- the joining of these small molecules into macromolecules such as proteins and nucleic acids 3- the packaging of these molecules into protocells, droplets with membranes that maintained internal chem different from surrounding 4-the origin of self-replicating molecules |
|
|
brief history from origin of planet to oceans forming |
-formed 4.6 billion years ago from condensation of vast cloud of dust and rock around sun -bombarded by chucks of rock and ice vaporizing all water -4 billion years ago bombardment ended setting stage for life -little oxygen, thick water vapor -earth cools oceans form |
|
|
different theories on organic compound formation |
1-Reducing environment- organic compounds formed from simpler molecules 2- deep sea hydrothermal vents first produced organic molecules 3- meteorites broth fragments of organic molecules |
|
|
progression of life history |
4600 years ago origin of earth prokaryotes eukaryotic cells algae and soft bodied invertebrate animals sudden divers animal explosion (Cambrian) fish vascular plants reptiles dinosaurs flowering plants mammals and birds origins of primates ice age origin of genus homo about 2.6 million years ago about 200,000 yrs ago modern human |
|
|
plate techtonics |
theory that continents are part of great plates of Earth's crust that essential float on hot underlying portion of the mantle. Mantle movement causes plates to move over time--continental drift |
|
|
5 mass extinctions |
Permian and Cretaceous |
|
|
permian extinction |
251 mil years ago during extreme volcanism episode claimed 96% or marine animal species and drastically altered ocean life. |
|
|
cretaceous extinction |
65.5 million years ago end of the dinosaurs except birds possibly due to iridium |
|
|
adaptive radiations |
periods of evolutionary change where groups of organisms form many new species whose adaptations allow them to fill different ecological rolls in their communities -happens large scale after every mass extinction |
|
|
homeotic genes |
determine such basic features as where a pair of wings and legs will develop on a bird |
|
|
hox genes |
product of one class of homeotic genes, provides positional info in an animal embryo to develop genes in a specific place |
|
|
phylogeny |
evolutionary history of a species of group of species |
|
|
taxon |
the named taxonomic unit at any level of the hierarchy |
|
|
taxonomic system |
family---orders--classes--phyla--kingdom--domain |
|
|
3 domains |
Bacteria (contains most of current prokaryotes), Archaea (contains prokaryotic organisms) and Eukarya (nuclei containing cells) |
|
|
p2 in Hardy W equation |
homozygous dominate |
|
|
q2 in Hardy W equation |
homo recessive |
|
|
2pq in Hardy W equation |
heterozygous |
|
|
history of earth as explained in class |
molten ball--cools, water vapor--oceans---1 billion years prokaryotes in water--- land starts forming--- photosynthesis---1st eukaryotic cells in water--- multicellular organisms--- movement onto land --- rise of reptiles --- first explosion of animals and primates--- homosapiens |
|
|
endosymbiotic origin plasmids |
used to live on their own, have their own DNA |
|
|
radiometric dating |
technique used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay. |
