organic evolution Exam 1 Questions & Answers

Descent with Modification - ANSWERS1. All species share common ancestry 2. Changes occur through natural selection Darwin and Wallace's insights - ANSWERSManuscripts with identical theories: 1) A population process: populations evolve, individuals don't 2) All organisms have a common ancestor How do we know something in science - ANSWERSDirect experimentation- control confounding variables Indirect experimentation- inference based on application of principles and laws in which we have confidence The Scientific method - ANSWERS Anaximander - ANSWERS520BC -Proposed species changed over time. -Speculated life had single origin and goes simpler --complex Xenophanes - ANSWERS500BC -Thought fossils held the key to earlier forms of life and speculated about evolution of living forms Plato - ANSWERS350BC - Essentialism Essentialism - ANSWERSEverything is perfect Aristotle - ANSWERS350BC -Species have immutable essence -Ladder of life Ladder of Life - ANSWERSEach species on a rung as hierarchical. No evolution Immutable Essence - ANSWERSNo evolution Jon Ray - ANSWERS1686 -English naturalist who classified plants based on observed similarities and differences -Defined the term "species" -Individuals of a species are similar as they descend from common ancestor. Steno - ANSWERS(1638-86) Father of geology and stratigraphy - Recognized record of historical change -Shark teeth Karl Linne (Linneaus) - ANSWERS1735 -Developed the current classification scheme for organisms including binomial nomenclature -"hierarchical scheme" Buffon (Georges-Louis Leclerc, Comte de Buffon) - ANSWERS1749 -proposed a modern definition of species based on the ability to produce fertile offspring. -Earth formed according to laws of physics and chemistry. Supported the idea of a long time scale. -Proposed different regions have different sets of animals and plants (Buffon's Law). Charles Bonnet - ANSWERS1770 (Angel Man) -proposed that organisms responded to natural catastrophes by evolving (kind of like natural selection) and that this evolution followed a pre-determined path (not like natural selection) -Apes were becoming men and men were becoming angels as they evolved. Immanuel Kant - ANSWERS1780 -proposed a common origin for living things and diversification based on need in different circumstances Cuvier (Georges Chretien Leopold Dagobert) - ANSWERS1800 -founder of animal paleontology -convinced of extinction but that evolution couldn't happen and that species couldn't change thru time. -Catastrophism - proposed the idea that catastrophes had caused mass extinctions to explain why fossils of different strata differed and why the boundaries between strata were sharp and not gradual. Erasmus Darwin - ANSWERS1800 -Published Zoonomia, agreeing that all living things were descended from a single ancestor and that they had diversified into the various forms seen today due to competition and social interaction. James Hutton - ANSWERS1788 -Proposed gradualism: that most geological change was small (volcanoes and earthquakes were exceptions) and that the Earth was old, allowing for great change to have accumulated. William Smith - ANSWERS() -Proposed each layer of rack had distinct fossils, and layers that were similar age had same fossils. -Created 1st geological map based on recognizing same layers of rock in different parts of England based on fossils in them. Charles Lyell - ANSWERS1830s -Renamed gradualism to uniformitarianism stressing that the forces of geological change seen today are the same as have been operating since the origin of the Earth, so we may understand ancient changes and predict future changes by studying current change. Jean-Baptiste de Lamarck () - ANSWERS1809 -Proposed separate origins for species through spontaneous generation and subsequent change by the Inheritance of Acquired Characteristics. -More complex forms had formed earlier and had more time to become complex. -Each species evolves toward a goal. Inheritance of Acquired Characteristics - ANSWERSCharacteristics changed as the use of them changed and these changes were passed on to the next generation. Evolution - ANSWERSChange in the genotypic and phenotypic characteristics of groups of related organisms (populations) over generations. -passed in the genetic material. -can vary from simple gene frequencies in a population to macroevolution. What sometimes happen if populations split and become isolated? - ANSWERSThey may diverge and over vast amounts of time this can explain biodiversity and relatedness. Evolution is NOT... - ANSWERS1) Changes in an organism due to development from zygote to adult (ontogeny) 2) Darwinism Darwinism - ANSWERSEvolution by natural selection Thomas Malthus - ANSWERS-1838, Darwin read essay by this person and observed that resources are either fixed or increase linearly but that human populations using those resources increase geometrically. -Felt shortages bound to happen once pop. caught up to amount of resource available. -competition inevitable Theory of Evolution - ANSWERS-Unifying idea explaining the life sciences and produces a tree-like model of branching common descent. -Essential to applied sciences. -Helps all fields to evolve thru time, like medicines evolve as bacteria evolve. Source of Biodiveristy - ANSWERSWhen populations split and Relateness - ANSWERSHow species on one island has a common ancestor/relative on another island. -That species had to branch off original as it adapted to new surroundings. Same species that evolved. Natural Selection - ANSWERSA) some variation among individuals in a population is heritable B) some variation among individuals affects the ability of the individual to survive, grow and reproduce (the "fitness" of the organism) C) those variations that are both heritable and improve the individual's fitness will increase in frequency in the population over generations D) The survival and reproduction of individuals is not random; it is tied to the variation among individuals. E) Focused on change within populations and he documented variation among individuals within a population. Adaptation - ANSWERSTraits that have evolved by natural selection Neo-Lamarckianism - ANSWERSinheritance of acquired characteristics regained popularity but August Weismann demonstrated that cutting the tails off of mice never became an inherited characteristic Orthogenesis - ANSWERSdisagreed that the environment set the course of evolution (no mechanism proposed) - felt that organisms progressed toward a set goal over time. Mutationism - ANSWERSevolution occurred in discrete jumps -"Hopeful Monsters" Mendelists - ANSWERSBelieved genetic change was discrete and sudden Biometricians - ANSWERSclaimed that genetic change was gradual and continuous - data from multifactorial characters The Modern Synthesis - ANSWERSDeveloped models of evolution using discrete mutations that resulted in evolutionary change consistent with Darwin's predictions of gradual change and that discrete mutations could lead to continuous change if multiple loci affected the character. - Mendelism and Evolutionary theory Post-Synthesis: Molecular Biology - ANSWERS-incorporated into Darwinian theory: -Watson and Crick, 1953 - Structure of DNA -J. Crow and M. Kimura introduced Neutral Theory of Evolution -wealth of discoveries about genes and genomes integrated into genetic theory (jumping genes, transposons, DNA duplications, epigenetic effects). Mayr's Summary - ANSWERS-Fact 1:All species have high fertility that the pop size would have exponential increase if all individuals that were born reproduced successfully -Fact 2: Except for minor annual and occasional major fluctuations, pops normally display stability -Fact 3: Natural resources are limited. In a stable envir. they remain relatively constant. -Inference 1: More individuals produced, resources not able to support, but pop size stable = fierce struggle for living among individuals of pop = survival of only a part (often very small part) of progeny of each generation. -Inference 2: Survival in the struggle for existence isn't random but depends in part on the hereditary constitution of the surviving individuals. This unequal survival constitutes the process of natural selection. -Fact 4: No 2 individuals are exactly the same; rather, every pop displays enormous variability. -Fact 5: Much of this variation is heritable. -Inference 3: Over the generations this process of natural selection will lead to a continuing gradual change of pops, that is, to evolution and to the production of new species. Why does Darwin get the most credit for the theory? - ANSWERSProduced a book about evolution through natural selection and had encyclopedic data and evidence to back up statements. Population - ANSWERSLocal group of interbreeding organisms. -All organisms of same group/species, which live in particular area, and have capability of interbreeding. Mutation - ANSWERSrandom and along with recombination is the source of genetic variation required by evolution. -Raw material for natural selection