week 1-Intro,Historical context and Neo Darwinism

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week 1-Intro,Historical context and Neo Darwinism by Mind Map: week 1-Intro,Historical context and Neo Darwinism

1. Intro

1.1. early ideas

1.1.1. aristotle 350 B.C. viewed species as unfixed/unchanging recognized affinities among organisms life forms could be arranged on a ladder/scale of increasing complexity

1.1.2. buffon 1749 earth old species change

1.1.3. geologists 1785 change gradual fossils catastrophism Lyell uniformitarianism

1.2. mechanisms of evolution

1.2.1. natural selection individuals in a species with best characters are chosen to survive and reproduce

1.2.2. sexual selection

1.2.3. artificial selection selecting and breeding individuals that possess desired characteristics

1.2.4. mutation

1.2.5. genetic drift chance haphazard component

1.3. evolution =descent with modification

2. Historical context

2.1. 3 schools of evolutionary thought

2.1.1. 1700 Linnaeus God species unchanged binomial naming system ascribed resembles among species on pattern of creation intrigued by cross pollination and hybrids

2.1.2. 1744-1829 Lamarck species change life out of nothing acquired characteristic passed to offspring stated that evolutionary change explains patterns in fossils and the match of organisms to their environments match of organisms to their environments can be explained by gradual evolutionary change published hypothesis in 1809 evolution happens because organisms have an innate drive to become more complex

2.1.3. 1800s Darwin + Wallis Malthus

3. Darwin

3.1. Voyage of beagle

3.1.1. 5yrs

3.1.2. orthodox ideas changed and emerged during sorting samples

3.1.3. Galapagos finches(islands) finches had different morphological features beaks due to diff food(insects) Darwin produced 1st phylogenetic tree to represent RL between species

3.2. origin of species

3.2.1. published 1859 6 editions not much about humans

3.2.2. implications church + religion could change the way ppl think may face criticism Darwin had to make sure he can argue 4 criticism

3.2.3. theory of evolution inherited variation within species competition for survival within species theory a type of framework that can get reviewed and refined depending on new discoveries basic fundamentals remain the same new findings/observations=new understandings

3.3. competition from Wallace

3.3.1. from a lower class background

3.3.2. came up with similar ideas to Darwin on evolutionary change species are changing wrote theory + sent to Darwin in form of scientific paper read at Linnean Society On the tendency of species to form varieties

3.3.3. collected species of beetles found intermediate steps between diff species travelled around Indo-Malaysia could see diff in Islands

3.4. Darwin was unsure about

3.4.1. age of earth thermodynamics 20/200million yrs not enough time 4 evolution

3.4.2. social insects sterility of worker bees isnt natural selection about reproduction+ survival type of grp selection could have evolved by GD

3.5. Darwin's Evidence

3.5.1. fossil record (paleontology) documents the pattern of evolution shows that past organisms differed from present day organisms shows that many species have become extinct shows evolutionary changes that have occurred in various groups of organisms shed light on origins of new grps of organisms e.g. cetaceans b4 cretaceans most mammals were terrestrial recent fossil discoveries shows that over time descent with modification produced increasingly lrg diff. among related grps of organisms ultimately results in diversity we have today

3.5.2. comparative anatomy on existing species e.g. similar bone structure but 4 diff functions homology characteristics that are shared due 2 a common ancestor have diff. functions e.g. forelimbs of all mammals analogy characters that are shared in two diff species but due to similar environmental factors e.g. marsupial mammals morphological series e.g. evolution of limbs from fins

3.5.3. comparative embryology similarities in developing embryos amongst diff species e.g. all vertebrate embryos have a tail located posterior(behind) the anus and a pharyngeal pouch(throat)

3.5.4. vestigial structures parts of the body/structures that have no used now but used to have a function previously (4 ancestors) e.g. thumbs,appendix,ear muscles e.g. skeletons of some snakes retain vestiges of pelvis and leg bones of walking ancestors eye remnants buried under scales in blind cave fish

3.5.5. domestication (artificial selection) e.g. dogs humans decide what characters are optimal selective breeding e.g. foxes for fur humans have modified other species over many generations selective breeding of individuals that possess desired traits

4. Natural selection

4.1. mechanism 4 evolution

4.2. overproduction of offspring

4.2.1. don't increase indefinitely not all reach maturity many eggs laid,young born,and seeds spread tiny fraction complete development and leave offspring of their own rest eaten,starved,diseases unmated or unable to tolerate environmental conditions some breed less

4.2.2. under optimal conditions all species have the capacity to overreproduce

4.3. natural variation

4.3.1. individuals within a population differ some diff affect survival and reproduction e.g. individuals in asian ladybird pop differ in color and spot pattern

4.3.2. e.g. giraffe necks giraffes with longer necks pass on trait to offspring better reproduction + survival than those with shorter ones longer necks=more food

4.3.3. Natural selection acts on these variations only if are heritable affect the beetles ability to survive and reproduce

4.4. speciation + diff between pops

4.4.1. caused by NS occurring independently on 2 pops of a single species

4.5. leads 2 adaptive change

4.5.1. environmental conditions change social and physical what is advantageous today might not remain so

4.6. main ideas

4.6.1. NS is a process in which individuals that have certain heritable traits survive and reproduce at a higher rate than other individuals

4.6.2. NS can increase the match between organisms and their environment

4.6.3. environment changes /individuals migrate to new environment NS may result in adaptation to new conditions sometimes give rise to new species

4.6.4. individuals don't evolve population evolves over time

4.6.5. NS can amplify/diminish only heritable traits that differ among the individuals in a population

4.6.6. environmental factors vary from place to place over time NS always operating which traits favored depends on context in which species lives and reproduces

5. neo darwinism / the modern synthesis

5.1. modification of darwins theory

5.1.1. same thing better understanding

5.1.2. aided by molecular biology advances and genome sequencing

5.2. 70s-80s