Evolution

• Evolution - refers to the changes in the proportions of biological types in a population overtime
• Evolutionary Theories

  • Creationism
  • Scala Naturae
  • Theory of Catastrophism
  • Uniformitarianism
  • Theory of Use and Disuse(Lamarckism)
  • Theory of Natural Selection
• Creationism- the belief that the universe and the various forms of life were created by God out of nothing (ex nihilo)
• Carolus Linnaeus - Proprietor for Scala Naturae
• Mimicry


  • Species resembles another in terms of behavior, appearance, sound, or even scent
• Batesian Mimicry


  • A dangerous organism (model) is mimicked by a harmless organism (mimic)
• Mullerian Mimicry


  • Two or more equally dangerous organisms use similar warning systems
• Divergence

  • When exposed to different environments, organisms develop different characteristics
• Species


  A group of organisms with the same number of chromosomes and can interbreed with one another to produce an offspring
• Camouflage


  • Blending with the environment
• Disruptive Coloration


  • Patterns (dark spots or stripes) to escape predators
• Countershading


  • Back side (dorsal) is darker than the front side (ventral)
• Cryptic Coloration


  • Matches its background
• Acryptic Coloration


  • Organism advertises its presence instead of hiding
• Structural Adaptation


  • Change in body color with the change in season
  • Change in color with growth
• Physiological Adaptation


  • Snakes produce venom to help it forage (overpower the prey), and self defense
  • Slowing down the heart rate and breathing to conserve energy
• Adaptation


  The process by which species adjust and thrive in their environment
• Fitness


  If an organism underwent Adaptation, then the organism has acquired a trait or a modification of a trait in order to make itself better suited in its environment
• Phylogenetics


  • Genetic relationships and evolutionary history of organisms
• Tree of Life


  • We are ALL related to a common ancestor
• Last Universal Common Ancestor (LUCA)


  Common, universal genes found in all genomes
• LUCA could have lived hidden away deep underground in iron-sulfur rich hydrothermal vents
• LUCA was Anaerobic and Autotrophic
• Comparative Embryology is the prebirth stage of an organism's development
• Human embryos and other vertebrates show striking similarities in the embryonic stage
• Comparative Embryology


  The study of similarities and differences in the embryonic development of different species
• Species with common ancestry have similarities in their DNA and amino acid sequences
• Comparative Biochemistry


  The study of similarities and differences in the biochemical composition of different species
• Biogeography


  The study of the geographical and temporal distribution of organisms on Earth
• Similar environments have similar types of organisms
• Different animals evolved certain common features because they were exposed to similar environmental pressures
• Homologous Structure


  Similar structure inherited from a common ancestor, but with different use/function
• Analogous Structure


  Similar structure not due to common ancestry, but evolved to do the same job, with different bone pattern
• Vestigial Structure


  A small remnant structure of something that was once much larger or more noticeable, and no longer has a use
• Fossil


  Remains or impressions of plants or animals preserved in rocks or sediments, used to compare organisms and provide information on ancestry and phylogeny
• Types of Fossils

  • Petrified
  • Imprints
  • Molds and Cast
  • Trace Fossils
  • Amber or Resin
  • Freezing
• Natural Selection


  The process by which organisms best adapted to their environment are more likely to survive and reproduce, leading to the gradual evolution of species
• Mechanisms of Natural Selection

  • Organisms tend to produce more offspring than the environment can support
  • Lack of resources and space results in increased competition
  • Organisms best adapted to the environment are most likely to survive and reproduce
  • All living organisms vary genetically
  • Organisms with favorable variations survive and pass these traits to their offspring
  • Variations may accumulate in succeeding generations
• Living things evolve, through natural processes, to better survive and reproduce within their environments
• All living things on earth are related in a single evolutionary tree