Evolution 1

• darwin was a naturalist
• lamark was a naturalist
• lamark said if you over use something, it'll get bigger
• lyell was to argue that laws of nature are constant over time
• lyell was a geologist
• thomas malthus noticed people were being born faster than people dying
• step 1 of evolution- selective pressure
• step 2 of evolution- genetic variety
• step 3 of evolution- individuals selected for or against (short term)
• step 4 of evolution- continued selection over generations (long term)
• step 1 and step 2 is requirements for change
• selective pressure- "something making survival difficult for individuals"
• external pressure (predator, disease)
• internal pressure- too many individuals, not enough food
• step 2- "individuals have different phenotypes"
• step 2- these differences must be genetic so traits can be passed on to offspring
• step 3- "selected for"- survive and reproduce less with their phenotypes
• step 3- "selected against"- survive and reproduce less with their phenotypes
• step 4- continued selection over generations (long term)
• step 4- the individuals "selected for" will continue to be selected and "the individuals selected against" will continue to be choose less
• species do change:

  1. study fast reproducing species
  2. studying fossils to see generations
  3. study bacteria
• fastest living species=bacteria
• anytime dna replication happens a mutation can occur
• studying fossils- find organisms from years ago (shows species do change)
• antibiotics are chemicals that destroy bacterial cells
• alexander Fleming discovered pencilin, the first true antibiotic
• antibiotics are beginning to lose their supremacy over bacteria. bacteria is evolving
• artificial-man made
• humans decide which alleles are beneficial- artifical selection
• evidence 2 )

  • studying artificial selection (plan and animal breeders)
  • studying natural selection (field biologist studying change)

  regardless they will change
• artificial selection humans decide which alleles are preffered
• evidence 1)

  • studying fast reproducing species
  • studying fossils to see generation

  Ex. Bacteria ( divide via type of cell division known as binary fission)

  
  

  Vestigial Structure: “vintage” a structure that an organism has that once served a purpose, but now, no longer serves a

  functional role in its body. Provides evidence that species do change.
• evidence 3) common ancestry

  • studying universal homology- what do every single thing have in common
  • studying recent homology - fairly new alike things (specific group of organsisms)
• homology- the study of alikeness
• recent homology

  
• what sturcture/trait are you paying attention to

  1. groups
  2. similar structures
• universal homology

  
• homologous anatomy- same enviroment
• mammals share embryo= common ancestory
• mutation , gene flow, genetic drift was not discovered my darwin