Final

• Evolutionary 'Theory' - The idea that all living things are related to each other and that they have evolved from earlier forms
• Evolutionary 'theory'

  • Based on solid evidence
  • continues to be tested
  • Not just one theory
• Theory - a guess or idea

  • isn't always supported by reliable evidence
  • or has not enough evidence
• Evolution - organisms change over time
• Macroevolution - change in a line of descent

  • at species level or above
  • usually takes long period of the time to happen
• Microevolution - change in gene frequency

  • just change in trait, within a population
  • below species level
• Darwin - "Descent with modifiation"
• Philosophers : GREEKS (384-322 BCE)

  Aristotle : "chain of being" or scala naturae"
• Chain of being

  A) Stone

  B) Flame

  C) Plant

  D) Beast

  E) Human

  F) Heaven

  G) Angel

  H) God

  
• Early Geologists : studied fossils and strata
• Georges Cuvier - Paleontology and Comparative Anatomy

  • Did not think species change over time, thought he was digging up species that DIED out over time
• Early Geologists :

  James Hutton : scottish geologist

  • principle of gradualism (1795)
  • Natural features of landscape form over gradual, long, periods of time through natural processes
• Early Geologists :

  Charles Lyell's - 3 volume "principles of Geology"

  Uniformitarianism
• Importance of early geologists ideas

  • gradual changes in earth's landscape
  • occurred by natural processes
  • took extremely long periods of time
• Early naturalists

  Linnaeus (1707- 1778) : Swedish physician + botanist

  • binomial nomenclature
  • hierachical 'nested' classification system
• Classification system

  Kingdom = the three domians of life

  Bacteria

  Archaea

  Eukarya

  A) Kingdom

  B) Phylum

  C) Class

  D) Order

  E) Family

  F) Genus

  G) Species

  
• Early naturalists

  Erasmus Darwin

  Zoonomia : laws of organic life

  • survivial of the fittest
  • origin and evolution of life over 'millions of ages'
  • relatedness of all forms of life
• Early naturalists

  Jean-Baptiste deLamark : First to propose a mechanism for change (1744 - 1829)

  • Also thought species change over time
  • believed 'principle of use and disuse' - More they used a feature, more prominant
  • believed 'inheritance of acquired characteristics' - wrong : only pass of the genes in your gametes
• Alfred Wallace - naturalist and biogeographer

  explored Brazil, Amazon River, then Malay Archipelago
• Mathus (pub 1798) : An essay on Principle of Population

  Big influence in Darwin and Wallace

  • Though populations were getting too big - Food was become more scarce
  • Predicted if we dont limit amount of population increase , food becomes limit which could start wars and etc
• Lyell and Hooker published the essays of Wallace and Darwin to Linnean Society jointly in June 1858
• Charles Darwin published on the origin of Species (1859)
• Darwins Ideas

  Key Observations

  1. Variation of traits in a population (genetic diversity)
• Darwins Ideas

  Key Observations

  2. Traits are inherited from parents to offsprings
• Darwins Ideas

  Key Observations

  3. Species produce offspring than the environment can support ; many die
• Darwins Ideas

  Key Observations

  4. Individuals with beneficial traits (adaptations) survive and reproduce, pass on traits to offspring

  (Natural Selection)
• Adaptation : A trait (noun) that favors survival or reproduction
• Natural Selection is a mechanism by which evolution occurs:

  1. Variation - some traits enhance survival
  2. Because an organism survives and reproduces, it passes on traits to offspring

  SO frequency of traits in a population change as a result of differential survival
• Artificial Selection: The process of selecting for a particular characteristic in a population.
• Sexual Selection: Also a mechanism that results in evolution

  1. Variation : some traits enhance reproduction

  • Some individual produce more offspring than others

  Reproduction success - Number of offsprings produced

  2. Traits that enhance RS are passed on to offspring
• Intrasexual selection: within same sex
• Intersexual selection: compete by influencing members of opposite sex to male
• Sexual dimorpism: different apperance between male and females (how sexual selection differs between two)
• Long - tailed widowbirds

  Experiment Compared :

  Males with short tails

  Males with long tails

  Males lengthened tails
• Long - tailed widowbirds

  Males with the longest tails got most mates. Long tails are selected for by sexual selection

  Though, they don't have the lengthened tails because it can impact survival

  thus, natural selection and sexual selection can counter each other

  can counteract and counterbalance one another
• Evolution : occurs over successive generations as population change in number of individuals that exhibit particular traits
• Natural (and sexual) selection : occur as a result of differential survival (reproduction) of individual

  • variation in traits is what selection acts on
  • individuals don't evolve populations or species evolve. Individuals vary.
• Adaptations : (noun) trait that benefits survival or reproduction

  • increase in frequency in successive generation

  Variation : key to a species adapting

  high variation : high (hetro) zygousity ( 2 different alleles )

  Low variation : Low (hetro) zygousity . High (Homo) zygousity (2 same alleles)
• Homologous structures : Similar structures / traits in different species due to a common ancestor with that trait
• Population : A number of individuals of same species living in the same area