Intro To Evolution Notes PDF

**Georges-Louis Leclerc, Comte de Buffon (1707-1788)**\ - Buffon was among the first [[Age of Enlightenment]](https://en.wikipedia.org/wiki/Age_of_Enlightenment) philosophers to suggest that the earth might be older than 6000 years.\ - An expert in many sciences from astronomy to biology, his life\'...

**Georges-Louis Leclerc, Comte de Buffon (1707-1788)**\ - Buffon was among the first [[Age of Enlightenment]](https://en.wikipedia.org/wiki/Age_of_Enlightenment) philosophers to suggest that the earth might be older than 6000 years.\ - An expert in many sciences from astronomy to biology, his life\'s work was creation of a *Histoire Naturelle*, an encyclopedia of all that was known about the world in his time.\ - Instead of using conventional Biblical wisdom,he referred to Newton\'s ideas about physics.\ - Evolution via migration\ - Buffon proposed that species change as they migrated from places of origin.\ His was the first known suggestion that living things could change over time. **Jean Baptiste Lamarck** In 1801, Lamrck presented his Theory of Inheritance of Acquired Characteristics Its main tenet: changes an organism acquired during its lifetime were passed on to its offspring Lamarck said these changes were driven by sentiment interieurs (inner feelings) - Acquired characteristics could be passed on to the individual's offspring **Georges Cuvier** - - **James Hutton** - - - - **An Evolutionary Glossary** **Gene**: a unit of inheritance, composed of DNA that controls a physical trait **Alleles**: Different versions of the same gene - **Locus**: the physical location of a gene on the DNA strand **Deme**: a local, actively interbreeding subpopulation that shares a distinct gene pool **Evolutionary adaptation**: the process by which a population evolves to become better suited to its environment **Artificial Selection** - - - - **Any trait may be...** **Adaptive** - increases the likelihood of reproductive success **Maladaptive** - decreases the likelihood of reproductive success **Neutral** - does not affect the likelihood of reproductive success - - - - - **The Organization of Life** Atom Molecule Marco Molecule Cell Tissue Organ Organ System Organism **Molecular Elements** - - - - - - A substance composed of two or more atoms is a **compound** **Organic Molecules** - - **Inorganic Molecules** - - **Biological Macromolecules** - - - - - - - **Nucleotides Form the Code** - - - - - - - - - - **DNA vs. RNA** - - - - - - - - - **The Central Dogma** - - - - - - - - **One Gene, One Protein** - - - - **Gene Expression** - - - - - **Some Proteins are Enzymes** - - - **Most Enzymes are Proteins** - - - - - - **How Do Gene Work** - - - **Mutations** - - - - - Mutations are RANDOM **Mutations can occur at the level of:** - - - - - - - - - - - - - - **From Zygote to Final Product** - - - - - - - **Cell Potency** - - - - - - - - - **Mutation: Timing is Everything** - - - - - **What is a Species** - - - **Reproductive Isolating Mechanisms** - - - - - **Prezygotic Reproductive Isolating Mechanisms** 1. - - 2. - 3. - 4. - 5. - **Interspecies Hybridization** - **Hybridization: Possible Outcomes** - - - - - - - - - - - - **Hybrid Zones** - - - **A living thing must have...** - - - - - - - **Understanding the Origin of Life** - - - - The Origin of Life was a process by which non-living matter acquired the qualities of life. Evolution is the process by which life changed after it had acquired those qualities. **Early Ideas About the Origin of Life** - - - **Francesco Redi** - - **Anton van Leewenhoek (1632 - 1723)** - - **Georges Buffon (1707 - 1788)\ -** This Parisian intellectual was the first European to propose that the earth and solar system had arisen via natural processes, though he did not propose a mechanism for this.\ - He noted that the earth and living things were all composed of the same types of \"particles\" (elements). **Lazaro Spallanzani (1729 - 1799)\ **In 1768, this Italian priest - - - - - But his experiments were criticized because - - **The Origin of Life: Modern Methods\ **We now know that life originated via four major phases 1\. Generation of small organic molecules from abiotic (non-living) precursors\ 2. Joining of these smaller subunits into biological macromolecules - - - - 3\. Packaging of these macromolecules into **protocells**: - - 4\. Origin of self-replicating molecules that made inheritance possible **Abiogenesis: Life from Abiotic Matter** - **Aleksandr Oparin (1894 - 1980)\ -** This Russian biologist published *The Origin of Life* (1924).\ - He proposed that chemical reactions in the ancient oceans could have generated life.\ - He studied mechanical ways that organic molecules might have formed the precursors of life. **Coacervates and Colloids** - - - - - **Add Lipids, Shake Well\ **Oparin combined - - And mixed them with a wavelike motion, mimicking that of the early ocean. Stable, globular coacervates formed. When **lipids** were added to the mixture, coacervates - - - **Protocells** - - **The Miller-Urey Apparatus\ -** Stanley Miller and Harold Urey were among the first to simulate the chemical conditions of the primordial oceans in the laboratory.\ - Stanley Miller, then a graduate student in Urey\'s lab, constructed the now-iconic **Miller-Urey Apparatus**. - -- -- -- -- - **Many Competing Hypotheses\ - Conventional Wisdom:** Earth\'s primordial atmosphere was [[reducing]](http://en.wikipedia.org/wiki/Reducing_atmosphere), and conducive to complex molecule formation.\ - **Alternative Hypothesis:** [[Earth\'s early atmosphere was only weakly reducing, or even neutral.\ ]](http://www.bio.miami.edu/dana/dox/Cleaves2008.pdf)**- Alternative Hypothesis:** [[Earth\'s early atmosphere was rich in either CO~2~] [or H~2~]](http://www.sciencemag.org/content/308/5724/962.short) (also conducive to complex organic molecule formation)\ - **Alternative Hypothesis:** Life may have its origin in places other than earth\'s surface, such as - - **RNA World Hypothesis\ - DNA** was once believed to be the key to the Origin of Life.\ - But more recent evidence suggests that it was actually **RNA** that appeared first, and is the reason that life itself evolved. - - - - - - \- Evolution of comparatively stable DNA from an RNA precursor would have been highly adaptive. [Evidence of Evolution in Living Things] **Observable Patterns of Life** ------------------------------- We can observe that\....\ 1. Life on earth is diverse (**interspecific variation**)\ \ 2. All life on earth can be joined in a single **phylogeny**.\ \ 3. There is genetic diversity within a species.\ \ 4. Organisms exhibit **adaptive traits**.\ \ 5. Organisms also exhibit **maladaptive traits**.\ \ 6. Biodiversity is not constant. - - Many patterns in Nature can be explained by\ **evolutionary processes**. **Pattern 1: Diversity of Life** Empirical fact: There are 5 - 50 million species on our planet. Of these, only 1.3 million have been named and described. **Pattern 2: The Tree of Life** Empirical Fact: DNA sequencing reveals that - - - This pattern continues as one compares the DNA of other species. More branches can be added to show the relative similarity of all living things. The branching diagram representing these relationships is a phylogenetic tree Empirical Fact: All life on earth can be arranged on a single phylogenetic tree. It is possible to devise this tree because - - - Empirical Fact: DNA composition is arbitrary - - - - Empirical Fact: All life can be reconstructed by a series of slight modifications of form - - - Evolutionary Inference: The tree of life looks like a family tree because it is its own. Evolutionary Theory: All existing species arose by means of evolution, descent with modification **Evidence for Modification: Homology** - - - - - Homology: Embryo Development - - - Ontogenetic Homologies - - - - - Vestigial Structures - Atavism: When Silenced Genes Awaken - - **Pattern 3: Adaptation** Empirical Fact - Evolutionary Inference - Evolutionary Theory - **Pattern 4: Maladaptation** Empirical Fact: Organisms are not perfectly designed. They have numerous design flaws and defects. **The Fossil Record** - - - - - **Types of Fossils** - - - - Organisms can be altered after death. Permineralization is the process by which water surrounding the body seeps into tissues, gradually replacing organic matter with water-borne mineral salts - - **Trace Fossils** - - - - - Trace fossils can - - **Stratigraphy** - - - As wind and water erode rock, particles wash into bodies of water where they settle anc solidify. As layers accumulate, lower layers compress and turn to stone. **Geological Principles** - - - - - - - - **Radiometry** - - - - - - **Isotopes** - - - - **Half Life** - **Relative vs. Absolute Dating** - - - **Carbon Dating** - **Biogeography** - - - - -