Chapter 4 - adaptations

Cards (38)

  • structural adaptation
    changes to the bones or limbs or organs of an organism to help to survive
    ex. talons and eyesight of an owl or the leaves of a buffaloberry
  • behavioural
    the actions an organism takes to survive
    ex. wolves hunting in packs
    "broken" wing of the kill deer
  • physiological
    sometimes called function, it is the general function of different parts of the body
    ex. gopher's slowing down their breathing rate during hibernation
    -production of hormones in humans
  • variation is created by sexual reproduction and the mixing of genes from both parents
  • variation is also increased by mutations
    -mutations are changes in the genetic material of an organism that may cause new characteristics to appear, may cause cells to die, or malfunction or may even cause tumours
  • aristotle
    believes all life existed in a perfected and unchanging form
  • buffon
    first to believe that there were relationships between organisms, earth was older than 6000 years
  • cuvier
    developed paleontology (study of life through fossils), discovered many changes in species, some appearing, some drying off, sudden events he called revolutions
  • lyell
    disagreed with revolutions, felt changes were slow gradual, and these changes are still occuring today
  • lamark
    came up with the idea theory of " inheritance of acquired characteristics"
    -this meant that the traits an individual developed would be passed on the offspring
    -there was a "force" or desire in organisms that allowed them to change themselves and then through use or disuse these features became more or less commons
  • darwin
    traveled on the beagle, made many observations of the new world and came up with a new theory of change still used today
  • wallace
    came up with a similar theory as darwin and conversed with darwin
  • malthus
    mathematician who came up with the idea that populations produce offspring that can actually survive
  • overproduction
    number of offspring produced is greater than the number that will survive to adulthood and survive
  • struggle for existence
    organisms of the same species must compete for resources due to overproduction
  • variation
    because of overproduction, there are differences between members of the same species
  • survival of the fittest
    those individuals in a species with traits that give them an advantage are better able to compete, survive, and reproduce. all others will die
  • inheritance of successful variations
    over many, many generations, a new species will arise due to the many advantageous characteristics becoming more common.
    -these traits must be passed on to the offpring
  • fossil record
    provides order of life because the deeper, the older the fossil. Younger layers are more similar to today's organisms
    -has now been proven through radiometric dating using isotopes
  • transitional fossil
    fossil that show intermediary links between groups of organisms that link past and present
    ex. organisms in drumheller and china
  • patterns of distribution
    darwin and wallace used the study of biogeography (study of past and present geographical distribution) to predict that animals evolve in one area and then spread out to other regions
    ex. geographically close areas have related species
  • anatomy
    relationships in structures of organisms
  • homologous structures
    similar structural elements and origin but may have different functions
    ex. horse leg, bat wing, and human arm
  • analogous structures
    body parts that perform similar functions but do not have evolutionary origin
    ex. insect and bird wing
  • vestigial structures
    structures that seem to be disappearing
    ex. wisdom teeth and appendix
  • embryology
    similarities among young embryos in related groups point to a common ancestral origin
  • molecular biology
    -study of parts of cells show us similarities
    1. all cells have a membrane
    2. proteins called enzymes do work
    3. proteins all come from amino acids
    4. all cells have dna
    5. dna is more similar organisms
  • genetics
    we now know how parents pass traits on to their offspring
    -understand the functions of dna
  • artificial selection
    the way we have created new vegetables and bred for new traits in dogs suggest evolution is possible
  • speciation
    formation of a new species can occur through 2 methods
  • transformation
    gradual development of a new species as a result of mutation and adaptation to a changing environment
    ex. one butterfly changes into a new one
  • divergence
    new species come from an original but the original remains in existence. results in many new individuals
    ex. the galapagos finches
  • geographical barriers
    mountains, rivers; does not need to be permanent but must be present long enough to cause organisms to become reproductive incompatible
  • biological barriers
    behaviours that change cause reproduction to be impossible. examples include bird calls and the leopard frog calls that are no longer recognized
  • reproductive barriers
    organisms are ready to mate at different times of year or sperms and egg will not join
    ex. finches
  • physical barrier separates on group from another mutations occur
  • natural selection works on the two groups differently creating unique variation in each group
  • accumulated differences between the populations become so numerous that even if the groups are reunited, the cannot interbreed