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;
47 Cards in this Set
- Front
- Back
Divergence of populations into separate species over time |
Speciation |
|
Fossils in deeper strata are ________ differ (less/more) from the modern ones today. |
older, more |
|
In _________ speciation, two populations become reproductively isolated. (no gene flow, populations diverge.) |
allopatric |
|
What are the two main types of reproductive isolation? |
prezygotic and postzygotic |
|
Reproductive isolation that occurs before a zygote can form |
prezygotic |
|
Reproductive isolation that occurs after a zygote can form |
postzygotic |
|
Prezygotic isolation that happens due to organisms living in different habitats (divided by natural barriers like mountains, rivers, canyons, oceans, living on different hosts, etc.) |
Ecological |
|
Prezygotic isolation that happens because the organisms breed at different times (frogs, fish, etc.) |
Temporal |
|
prezygotic isolation that happens when the organisms behave different (different mating rituals) |
Behavioral |
|
Prezygotic isolation that happens when mating doesn't structurally work. "Lock and key" (beetles) |
Mechanical |
|
Type of postzygotic isolation that results in hybrids being aborted, stillborn, or weak |
Hybrid inviability |
|
Postzygotic isolation that results in hybrids that cannot themselves reproduce |
Hybrid sterility |
|
First generation hybrids can survive and reproduce, but the second generation ones die or cannot reproduce. |
F1 Hybrids are inviable |
|
A population forms two different niches within existing habitat (mate by apples vs. mate by hawthorn fruits) |
Sympatric Speciation |
|
Population evolves as it moves in a circle, when they meet up at the end they can no longer reproduce. |
Ring Species |
|
Has more sets of chromosomes than it should have. (normally haploid, become diploid, triploid, tetraploid, hexaploid, or octaploid) |
Polyploidy |
|
What's it called when an organism has a normal amount of chromosomes? |
Haploid |
|
What's it called when an organism has a double set of chromosomes? |
diploid |
|
Polyploidy is usually fatal in _______, but is used all the time in cross-breeding ______. |
mammals/animals, plants |
|
What are the four mechanisms for a change in a population? |
Genetic Drift, Natural Selection, Reproductive Success, and Cooperation. |
|
Random movement of gene frequency, usually eliminates new genes as traits become homozygous ("fixed") |
Genetic Drift |
|
Small founding populations have a different gene frequency / less variation than the source population, difference gives it a head start toward changing. |
Founder Effect |
|
When we choose which organisms to breed depending on the presence or absence of specific traits |
Artificial Selection |
|
Conditions in which organisms survive "chooses" which varieties survive by removing the less likely to survive genes from the gene pool |
Natural Selection |
|
Type of natural selection that eliminates the extremes from the gene pool |
Stabilizing |
|
Type of natural selection that eliminates one extreme from the gene pool |
Directional |
|
Type of Natural Selection that eliminates the medium of a trait; extremes become more common. May end up with two different species. |
Diversifying/Disruptive |
|
Type of selection that acts on an organism's ability to obtain or copulate with a mate (coloration, antlers, other structures, territorial defense, suicidal mating, spermatoplylax...) |
Sexual Selection |
|
Anything that can increase the number of offspring and can increase the number of traits. (mating with more mates, more eggs, more parental care) |
Reproductive Success |
|
Helping your relatives (they have similar genes) |
Cooperation |
|
A change in the DNA, results in new traits. |
Mutation |
|
These can bring in traits from another species |
Fertile hybrids |
|
Bacteria and viruses can swap DNA |
Vectored DNA |
|
Type of mutation in which one base changes to another base |
Substitution |
|
Type of mutation in which one or more bases are added |
Insertion |
|
Type of mutation in which one or more bases are left out |
Deletion |
|
Any mutation that changes how triplets are read (often removes a trait or protein) |
Frameshift |
|
New mutations are often lost to _____ ______ |
Genetic Drift |
|
Analagous parts of chromosomes trade places during mitosis or meiosis |
Crossing Over |
|
Mating is ______: you can't control which gametes are involved. |
Random |
|
_________ sort independently during meiosis, which increases a population's variation. |
Chromosomes |
|
Life on Earth has changed, and is still changing. |
Evolution |
|
The key to the past is the present. The environmental processes that happen now are the same as the ones in the past. |
Uniformitarianism |
|
This mass extinction wiped out the dinosaurs and was followed by bird, then mammal radiation. |
K-T boundary |
|
This mass extinction nearly removed all life from Earth, and was followed by dinosaur radiation. |
End Permian |
|
A change in genetic frequency; a new trait appears or is lost; an existing trait becomes more common. The changes that we see. |
Microevolution |
|
A whole lot of microevolution; a new species forms. (When depends on how you define species.) |
Macroevolution |