Biology – Evolution Latest 2023 Graded A+

Biology – Evolution Latest 2023 Graded A+ evolution change in species over time populations evolve, individuals don't! population all of the individuals of a species that live in an area variation heritable differences in the physical traits of an individual from those traits of other individuals in the population species group of organisms that are closely related and can mate to produce fertile offspring speciation process in which new species are formed over time adaptation a feature that allows an organism to better survive and reproduce in its environment - certain variations can allow an individual to survive better than others charles darwin the father of evolution charles darwin's birth 1809, in england charles darwin's ship HMS Beagle charles darwin's discovery organisms change over time natural selection mechanism by which individuals that are better fit for their environment have a greater chance to survive and mate/reproduce mechanism of evolution how does evolution happen natural selection, mutations, artificial selection, geographic separation/isolation., genetic drift, gene flow(migration) organism with adaptation more common or frequent over time organism without adaptation less common or frequent over time principles of the theory of natural selection 1. variation 2. overproduction 3. adaptation 4. descent with modification overproduction not all offspring will survive due to competition descent with modification the number of individuals with the advantageous adaptations will increase over each generation natural selection acts on... traits that already exist phenotypes: new alleles occur by genetic mutations artificial selection the process by which humans change a species by breeding it for certain traits fossil trace of a dead organism types of dating for fossils radiometric and relative radiometric dating uses the known time of natural decay of unstable isotopes to calculate the age of the materials relative dating estimates the age of fossils by comparing the fossils found in certain rock layers to those in other layers oldest fossils found in the bottom of the rock youngest fossils closest to the surface fossil doesn't form decomposition takes place biogeography study of the geographic distribution of plants, animals and fossils homologous structures common ancestor similar structure different function examples of homologous structures bones of a cat, human, whale, and bat are similar but have different functions analogous structures not related different structures same function examples of analogous structures bird wing and insect wing quills on a sea urchin, hedgehog, and cactus vestigial structures no useful purpose examples of vestigial structures pelvic bone in a whale human appendix human canine teeth and wisdom teeth embryology similarities in embryological development among organisms is further evidence of shared common ancestry molecular evidence more similarities in DNA between 2 organisms, the more closely related they are; the more differences, the more distantly related gene pool combined alleles of all the individuals in a population alleles difference forms of a gene frequency how often something occurs over time genetic variation in a population increases the chance that some individuals will survive genetic variation sources mutations recombination mutations random change in the DNA of a gene; is the change occurs in the DNA of a reproductive cell then it will passed on to the offspring recombination new allele combinations in an offspring that occurred during meiosis through crossing over and independent assortment gene flow movement of alleles from one population to another increases genetic variation of the receiving population migration (immigration, emigration) other word for gene flow lack of gene flow leads to formation of different species genetic drift change in allele frequency due to chance; results in loss of diversity types of genetic drift bottleneck effect founder effect bottleneck effect when a population is drastically decreased due to a natural disaster founder effect when a small group splits off from a larger population and starts their own population isolated from the original population random mutation -can happen to one individual in a population and can be beneficial, harmful, or neutral -can increase chances of survival and reproduction -can decrease chances of of survival -might not affect an indivduals ability to survive and reproduce and will become a natural variation instead of a mutations sexual selection occurs when certain traits increase mating success hardy-weinburg 1908-two scientists created an equation to test these ideas of probability and chance hardy-weinberg principle the frequency of alleles in a population does not change unless evolutionary forces act on population characteristics of a hardy-weinberg population -very large population -no migration -no mutations -random mating -no natural selection reproductive isolation -when members of different populations of the same species can no longer mate successfully -can lead to speciation 3 barriers that can cause reproduction isolation to occur behavioral barriers geographical barriers temporal barriers behavioral barriers courtship or mating behaviors are now different in the populations geographical barriers physical separation of the populations temporal barriers the two populations aren't ready to mate at the same time of day convergent evolution individuals share similarities not because they are related but because they need certain adaptations to survive in their environment; therefore, they have analogous structures parallel evolution another word for convergent evolution divergent evolution the process by which one species begins to split into two distinct groups with different traits; therefor they have homologous structures adaptive radiation another word for divergent evolution and may lead to speciation phylogenetic tree a diagram showing the evolutionary history of a species - divergent evolution coevolution process in which two or more species evolve in response to changes in each other extinction elimination of a species usually as a result of it's inability to adapt to a change in the environment gradualism slow changes happen continuously over a long period of time punctuated equilibrium bursts of rapid change in species are separated by periods of little to no change Heritability statistic that estimates how much variation in a phenotypic trait in a population is due to genetic variation among individuals in that population. Fitness the ability to survive to reproductive age, find a mate, and produce offspring. Sympatric Speciation Speciation that takes place without geographical separation. Allopatric Speciation Speciation that occurs BECAUSE of geographical separation. Peppered Moth is an evolutionary instance of directional color change in the population as a consequence of air pollution during the Industrial Revolution. Isotope version of an element that has extra neutrons and often gives off radiation. Half-Life the time taken for the radioactivity of a specified isotope to fall to half its original value. Binomial Nomenclature Two name naming system used by scientists to classify organisms. Dichotomous Key a tool that allows the user to determine the identity of items in the natural world, such as trees, wildflowers, mammals, reptiles, rocks, and fish.