BIOL 152 1st Edition Lecture 2Outline of Last Lecture: - Gene Transcription and Translation Outline of Current Lecture:Evolution - Scientific theory that explains the origin of earth’s species (biodiversity) by gradual change over time - Descent with modification from common ancestor- Is a principal unifying concept in biologyTheory- Is a comprehensive and well supported statement backed by large amounts of evidence Overview- Evolution – change in a population’s allele frequency over time- Natural Selection – differential success in the survival and reproduction of different phenotypes resulting from the interaction of individuals with environment- Evolutionary adaptation – accumulation of inherited characteristics that enhance organism’s ability to survive and reproduceA great resource: http://evolution.berkeley.edu/evolibrary/article/evo_01Aristotle 384-322 B.C.- Created the Scala Naturae- Stated that species are unchanging and arranged species on a ladder of increasing complexity, with human being at the top of the ladder- This was the principal model of biological thought until the 18th century The Scientific Community in the 1800sThese 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.- Carolus Linneaus created the taxonomy of species, arranged by grouping similar species- Highly known for creating the binomial nomenclature Defining Earth Georges Cuvier: - Used paleontology to define the mechanism of how Earth functions - Stated the theory of Catastophism, which states that the Earth had been affected in the past by violent events that led to extinctions and producing adaptive radiation.James Hutton: - Used geology to define the mechanism of how Earth functions- Stated the theory of Gadualism, the cumulative effect of slow but continuous processes that have produced earth’s geologic formationsCharles Lyell: - Stated the theory of Uniformitarianism, that same geologic processes that happened in the pastare happening today at the same rate- Darwin agreed and realized that if true, the Earth was older than 6,000 years old, which many thought it was during Darwin’s time Theory of Evolution Jean-Baptiste Lamarck:- Stated that evolutionary change is based upon two principles:o Use and disuse o Inheritance of acquired characteristics Charles Darwin:- Went aboard the HMS Beagle- Noticed how geologic change can be explained using fossil record- Observed taxonomy that showed continental affinities and also showed similarities between extinct and living forms in the same locale- Observed unique species groups on Galapagos Islands that were Endemic- Observed the adaptation of organisms to the environment and the origin of new speciesCharles Darwin’s Theory of Evolution - Descent with Modificationo All organisms are related through descent from a common ancestor that lived in the remote pasto Over time, descendants have accumulated modifications that allow them to survive and reproduce in specific habitatsDeciphering the Theory of Natural Selection- Ernst Mayr (1904-2005), an evolutionary biologist, broke down Darwin’s work into 4 observations and 2 inferenceso Observation #1: individuals of a population vary extensively in their characteristics o Observation #2: traits are inherited from parent to offspringo Observation #3: all species have an ability to reproduce and population will increase exponentiallyo Observation #4: environmental resources are limited and as result populations tend to be stable o Inference #1: Individuals whose traits are best suited for survival are likely to leave more offspring than less fit individuals. “Survival of the Fittest”o Inference #2: The unequal ability to survive and reproduce will lead to the gradual accumulation of favorable traits over generations.Malthus (1766-1834) - Human population growth is geometric/exponential- Growth kept in check by famine, plagues, and late marriageSummary of Natural Selection 1. Individuals do not evolve, only populations do2. Can only act on heritable traits3. Environmental factors vary in space and timeObservations of Evolution Direct Observation:- Drug resistance in bacteria and viruseso For example, if antibiotics for a given bacteria is successful in eliminating bacteria, there will always be a select few in the next generation that are resistant to the bacteria, because of the parent being immune to the antibiotic. - Pesticide/herbicide resistance in agricultureo For example, if insecticides are used to kill mosquitoes, then there will be a select few in the population that are resistant to the insecticide and those genes will then be passed onto the offspring, which will remain immune to the insecticide. - Homologies: Similar traits that arose from common ancestry- Developmental observationso ‘Ontogeny recapitulates phylogeny’ - animals go through stages that seem to all resemble each other, when organisms are going through successive embryonic stages. This theory is discredited, but it shows how evolutionarily organisms looked alike during embryonic stages. o Genetic observation Evolution and Cancer 1. Variation (due to mutations)2. Differential birth and death rates 3. Heredity Overview of Observations of Evolution 1. Direct Observations2. Homologies 3. Fossil Record Current Lecture:- Evolution of