BIOL 1107 1nd Edition Lecture 36Outline of Current LectureI. Populations and Change II. Variations III. Pre-zygotic and Post-zygotic Mechanisms IV. Speciation Outline of Current LectureI. Darwin and His Observations and Inferences II. Evidence of EvolutionIII. DNA Sequences & Predictions Current LectureI. Darwin and His Observations and Inferences- Darwin’s Observations:o (1) Members of a population have varying traits (not everyone was uniform)o (2) When they reproduce, they produce more offspring than the environment was capable of handling (carrying capacity) -> many failed to survive - Darwin’s Inferences: o (1) Traits are able to survive and reproduce more offspring o (2) Uneven ability will leave more favorable traits in population. o What is needed for “descent with modification” of a trait? Variation in a trait in a population Trait must be heritable—genetically controlled Differential survival and/or reproduction (ex: having different colored fur is important in certain animals)II. Evidence of Evolution- Direct Observation These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o Scientists have directly observed evolution in many instances, including the development of drug resistance in bacteria and other pathogens. - Homology -> can see similarities between certain species o Limbs of several species (human, cat, whale, bat)o Homologies include similarities in structure, development, and DNA sequences in different organisms. o Vestigial structures are homologous structures that have a reduced function or no function at all. Examples include the pelvic bones of whales. - Snake vs. lizard -> vestigial leftover (fragments of femurs)III. DNA Sequences & Predictions- Related organisms should have similar genes - Mutations are random and accumulate - The longer species are separate = more differences - Predictions:o Organisms can be organized into phylogenetic family trees o Closely related organisms have more similar characteristics - When different characteristics are examined, give very similar phylogenetic trees. - Implication:o All organisms share a common
View Full Document
Unlocking...