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| 7224139889 | early life | simple prokaryotic life began around 3.5 billion years ago. The first living things were most likely anaerobic (without oxygen) heterotrophs (get their energy from other materials, not from photosynthesis). | 0 | |
| 7224139890 | Miller-Urey | experiments that recreated the conditions of early earth showed that it was possible for organic molecules (amino acids) to be created from the gasses present plus added energy from lighting/etc.) |  | 1 |
| 7224139894 | Pangea | a single landmass where the continents were connected around 250 million years ago |  | 2 |
| 7224139896 | adaptive radiation | periods of evolutionary change where many new species evolve from a common ancestor, often following colonization of new, unexploited areas or followed by mass extinction events. |  | 3 |
| 7224139897 | phylogenetitic trees | models showing a hypothesis of how species are evolutionarily related. Phylogenetic trees are hypothesis based on evidence, but the trees themselves do not provide evidence. Evidence could be from comparing DNA, comparing structures, etc. | 4 | |
| 7224139898 | parsimony | theory that the simplest solution is probably correct. It is more likely that a trait evolved one time and got passed onto all of the descendants from a common ancestor than that a trait evolved multiple times (although the latter is possible) | 5 | |
| 7224139900 | biological fitness | biological fitness is measured by how many offspring an individual prodces. More offspring = higher biological fitness |  | 6 |
| 7224139901 | Population | A group of individuals of the same species that live in the same area and interbred. | 7 | |
| 7224139902 | Variation | there are different heritable traits within a population, caused by random mutations, and by crossing over and independent assortment for Eukaryotes | 8 | |
| 7224139903 | Adaptation | A trait that allows species to fit in a specific environment in a specific way. | 9 | |
| 7224139904 | Natural selection | one mechanism for how evolution occurs: not every individual survives long enough to reproduce, there is variation of traits, those individuals with traits that are better adapted to their environment survive and reproduce, and over time those traits become more frequent in the population | 10 | |
| 7224139908 | evolution | only occurs at the level of a population, not an individual; a change in population's traits over time | 11 | |
| 7224139909 | Homologous structures | Features that often have different functions but are structurally similar because of common ancestry. Examples bones in the limbs of a whale, human, and bat. |  | 12 |
| 7224139911 | allele | a single copy of a gene. Animals have two alleles for each trait, one from each parent. (Males only have 1 copy of traits found on the X and Y chromosomes.) If the dominant trait is Brown hair, the allele for brown hair would be "B" and the recessive trait is red hair would have the allele "b" | 13 | |
| 7224139912 | p | frequency of the dominant allele in a population | 14 | |
| 7224139913 | q | frequency of the recessive allele in a population | 15 | |
| 7224139914 | p^2 | frequency of individuals in a population with a homozygous (both same) dominant genotype. (example: BB for dominant brown hair) | 16 | |
| 7224139915 | 2pq | frequency of individuals in a population with a heterozygous genotype (example: Bb one dominate allele and one recessive allele) | 17 | |
| 7224139916 | q^2 | frequency of individuals with homozygous (both same) recessive genotype (example: bb, two recessive alleles) | 18 | |
| 7224139917 | Hardy Weinberg Equilibrium | H-W is in equilibrium from one generation to the next if evolution is NOT occurring. The two key equations are p^2 + 2pq +q^2 = 1 and p+q=1 |  | 19 |
| 7224139918 | Microevolution | a change in the frequency of alleles in a population. There are five forces of microevolution, but only natural selection helps species to become better adapted to their environments over time | 20 | |
| 7224139919 | genetic drift | One of the non selective forces of microevolution. Chance events that can cause allele frequencies to fluctuate unpredictably from one generation to the next. This occurs more frequently in smaller populations. Examples include natural disasters that reduce the population size ("bottleneck effect") or when a few individuals colonize a new place ("founder effect") |  | 21 |
| 7224139920 | gene flow | One of the non selective forces of microevolution. When alleles change from immigration or emigration of genes. Allele frequencies in a population in which a population may gain or lose allele when fertile individuals move into or out of a population or when gametes are transferred between populations. |  | 22 |
| 7224139921 | sexual selection | one of the non selective forces of microevolution when one sex of a species favors specific traits in mates of the opposite sex. This leads to sexual dimorphism (great differences between individuals in a species between the sexes). Example, peacock feathers |  | 23 |
| 7224139922 | species/ biological species concept | idea that two individuals are in the same species if they could interbreed and produce viable, fertile offspring | 24 | |
| 7224139923 | Speciation | The Evolution of a new species. Speciation requires both some type of isolation/separation of an initial population into two population, and it also requires microevolution/selection over many generations. Speciation can occur rapidly or slowly |  | 25 |
| 7224139924 | Allopatric speciation | speciation that occurs because populations separated by a geographic barrier | | 26 |
| 7224139925 | Sympatric Speciation | speciation that occurs when populations are living in the same geographical area. | 27 | |
| 7224139926 | Reproductive isolation | One mechanism for separating a population. The existence of biological factors that impede members of two species from producing viable, fertile hybrids | 28 | |
| 7224139931 | hybrid sterility | when the offspring of two species cannot mate (for example horses and donkeys mate to produce mules, but the mules are sterile) | 29 |
