finals

Relative fitness - the contribution an individual makes to the gene pool of the next generation relative to the contributions of other individuals

Theory - A hypothesis that has been tested with a significant amount of data

Evolution - Living species are descendants of ancestral species

Natural selection - Better adapted individuals more likely to survive and reproduce.

Adaptation - Evolution that results in better fit between organism and environment

Strata - Rock layer form when new layer/sediment converse old one & compresses it

Homologous structures - Features that have different functions, structurally similar to common ancestry

Vestigial structures - Remnants of features that served important function in ancestor

DDT pesticide use resistance (describe) - When mosquito population gets sprayed with DDT, the allele that has an enzyme that breaks it down will increase by each generation.

Hardy-Weinberg Equilibrium - State of population, frequencies of alleles & genotype remain constant from 1 generation to another only if Mendelian segregation & recombination of alleles work.

Genetic drift - Chance events cause allele frequency fluctuation for generations

Bottleneck effect - Drastic decrease in population

Founder effect - Genetic drift from a few individuals being isolated which forms a new population that isn't the original.

Gene flow - Transfer of alleles from 1 population to another from movement of individuals or gametes

Directional selection - Favors intermediate variants, against extreme phenotypes

Disruptive selection - Environmental conditions favor individuals at both ends of the phenotype range over intermediate phenotypes

Sexual selection - Form of natural selection, certain traits more likely than other individuals to obtain mates

Sexual dimorphism - Marked differences between secondary sex charecterisitscs of males & females

Balancing selection - Natural selection, maintains stable frequencies of 2 or more phenotype forms in population.

Heterozygote advantage - Type of balancing selection, heterozygous individuals have better reproductive success than homozygous

Why are there organisms that exist that seem less than ideally selected for their environment? - 1. Natural selection favors fittests variants, may not be ideal traits

2. Evolution doesn't scrap ancestral anatomy, rather it builds off it

3. Every adaption has compromises - E.g. webbed feat good for swimming on water, not good on land

4.Events can affect genetics of population, e.g. individuals may be blown to other population by storm.

Genetic drift in small populations may get rid of beneficial alleles

Environment changes every year, may change effectiveness of allele.

Speciation - emergence of a new species from natural selection

Biological species concept - species as a group of populations who have potentially interbreed in nature, produced fertile offspring

Reproductive isolation - Barrier that stops members of 2 species from producing fertile offspring

Hybrids - Offspring of pairs who are a different species

Morphological species concept - Definition of species in measurable anatomical criteria (looks)

Ecological species concept - Identifies species for their ecological niches (unique adaptions than roles in community)

Phylogenetic species concept - Species as smallest group of individuals, share common ancestor, one branch on tree of life

Prezygotic barriers - Hinders fertilization between 2 species.

Postzygotic barriers - Hinders fertilization by preventing the creation of fertile adults

Allopatric speciation - Population is divided into geographically isolated subpopulations

Adaptive radiation - Evolution of diverse species from a common ancestor

Hybrid zones - Regions where different species mate and produce hybrid offspring

Reinforcement - Natural selection strengins, reinforce reproductive barriers eventually reducing formation of unfit hybrids.

Fusion - two hybritized species turn into 1 species

Stability - Tendency for 1 or more species to maintain character over long time

Conditions of early Earth (list) - Thick water vapor & volcanic eruptions

Lightning

UV radiation

Stromatolites - Layered rock from past activities of prokaryotes which binds sediment together

Four main stages of simple cell evolution (list) - 1. Abiotic (non living) synthesis of small organic molecules, (amino acids & nitrogenous bases)

2. Small molecules to polymers (proteins & nucleic acid)

3. Packaging of molecules into "protocells", droplets with membranes maintain internal chemistry different than environment

4. Origin of self replicating molecules made inheritance possible

Macroevolution - Evolutionary change above species level

Radiometric dating - Method, determines age of fossils & rocks on half life radioactive isotopes

Geologic record - Time scale by geologists, divies Earths history into 4 eons (Hadean, Archean, Proterozoic, Phanerozoic)

5 mass extinction events (list) - 1. Ordovician Extinction

2. Late devonian extinction

3. Permian Extinction

4. Triassic extinction

5. Cretaceous Extinction

Sixth mass extinction - Human activities modifying global environment making species close to extinct

Exaptations - Structure that evolved who had 1 function change to another function

Goal-directed evolution (why is it incorrect?) - Evolution is from interactions between organism and current environment.

Taxonomy - Branch of biology dealing with identifying, naming, & classifying species

Binomial - 2 part scientific name

Linnaeus system of classification (list categories) - 1. Species

2. Genus

3. Family

4. Orders

5. Classes

6. Phyla

7. Kingdoms

8. Domains

Phylogenetic trees - Branching diagram, represents hypothesis about evolutionary history of organism groups

Convergent evolution - Similar environments & natural selection produce similar adaption in different organisms.

Analogy - Similarity from convergent evolution

Cladistics - A character members of particular clade from ancestor that isn't part of a clade

Parsimony - Simplest explanation for observed phenomena

Molecular systematics - Method, uses DNA/ other molecules to infer how organisms are related(E.g. evolution)

Molecular clocks - Estimates actual time of evolutionary events from DNA changes

Meiosis - Cell division that produces reproductive cells in sexually reproducing organisms

Gametes - sex cells

Haploid - 1 set of chromosomes

Diploid - 2 sets of chromosomes

Independent Assortment - the random distribution of the pairs of genes on different chromosomes to the gametes

Crossing over - Process in which homologous chromosomes exchange portions of their chromatids during meiosis.

Chiasma - site of crossing over in chromosomes

Homologous Chromosomes - Chromosomes that have the same sequence of genes and the same structure

Karyotype - A display of the chromosome pairs of a cell arranged by size and shape.

Inversion Mutation - Mutation in which a chromosome piece reattaches to original chromosome but in reverse orientation

Translocation Mutation - mutation in which one part of one chromosome breaks off and attaches to another

Insertion Mutation - a mutation in which one or more nucleotides are added to a gene

Duplication mutation - a mutation that involves duplication of a region of DNA on the same strand

Homozygous - An organism that has two identical alleles for a trait

Heterozygous - An organism that has two different alleles for a trait

Alleles - Different forms of a gene

Dominant Allele - An allele whose trait always shows up in the organism when the allele is present.

Recessive Allele - An allele that is masked when a dominant allele is present

Law of dominance - In many traits one allele is dominant over the other allele. The "weaker (recessive" allele is only expressed when it is paired with another recessive allele

Phenotype - An organism's physical appearance, or visible traits.

Genotype - genetic makeup of an organism

Gene Loci/locus - specific locations of genes along the chromosome

Carrier - A person whose genotype includes a gene that is not expressed in the phenotype.