Download Evolution Notes : Theories on the Origin of Life is the theory that life

Evolution Notes : Theories on the Origin of Life
__________________________________________________ is the theory that life can come from
_________________________________________matter. (Frogs come from mud, flies come from garbage, etc.)
______________________________________________–life arose from a combination of inorganic chemicals methane
(CH4), ammonia (NH3) + water (H2O) that existed in the ancient oceans of earth.
Experiments to disprove spontaneous generation
_______________________________________________- disproved spontaneous generation
Showed that rotting meat kept away from flies would not produce new flies
Maggots appeared only on meat that had been exposed to flies
Eggs laid on
meat
_____________________________________________- 1700s
Microorganisms would not grow in broth when its container was heated and
then sealed
Inferred that microorganisms do not arise spontaneously
Microorganisms were carried in the air
______________________________________________- Used variation of Spallanzani’s
experiment
Used curve-necked flasks
Microorganisms were prevented from entering the flask
When curved necks were broken, broth became cloudy with microorganims
Experiments to prove Abiogenesis Hypothesis
_____________________________________________ and ________________________________________________- proposed that at
high temperatures the gases of early Earth formed simple compounds (eg. amino acids)
When earth cooled, water vapor condensed to form lakes and seas, compounds collected in the water
Compounds entered complex chemical reactions
Resulted in _____________________________________________________ (eg. Proteins)
Synthesis of Organic Compounds
________________________________________________________- Used Oparin’s hypothesis to setup experiment
Produced amino acids and other organic compounds
_____________________________________________________- Endosymbiotic,
aerobic prokaryotes evolved into modern mitochondria and
Photosynthetic cyanobacteria evolved into chloroplasts
Theories of Evolution
__________________________________________ – slow, gradual change over
time
____________________________________________evolution – changes in the non-living planet over time.
____________________________________________evolution – changes in living organisms over time.
Geologic Evolution
_________________________________________________- Uniformintarianism ( geologic processes are still changing
the Earth at a uniform rate)
_________________________________________________- Gradualism( changes in the Earth is due to slow continuous
processes such as erosion, earthquakes, and volcanoes)
Biological Evolution
__________________________________________________- Use and Disuse – He hypothesized that organisms were
able to develop new structures as they needed them and they were able to pass them on to their
offspring. This was called the..______________________________________________________________________________________
Got evolution right, but got mechanism wrong !!
___________________________________________________________ – characteristics genetically passed on the offspring.
___________________________________________________________ – a trait that develops during an individual’s lifetime.
______________________________________________________- Observed that babies were being born faster that people
were dying. Population size is limited by resources.
Reasoned that if the human population continued to grow unchecked that there would be famine and
disease in order to balance population size.
____________________________________________- Naturalist aboard the HMS Beagle collected hundreds of
specimens and made extremely detailed observations of the natural world on the 5 year scientific
expedition. Developed the Theory of ___________________________________________
Wrote (1845) his famous book “On the Origin of Species”
Darwin observed plants and animals on the Galapagos Islands
Examples:____________________________________ had different types of beaks on the different islands adapted to
their type of food gathering.
___________________________________________________ on different islands had different neck lengths.
Darwin’s Theory of Natural Selection
#1 ________________________________________________ (got from Malthus)
Organisms tend to have many more than two offspring so at least some will survive (yet populations
usually do not grow rapidly in the wild)
#2 _______________________________________________ - Therefore they must compete for resources (food, space,
mates)
#3 ______________________________________________ - differences within the population.
#4 ______________________________________________ – characteristics that make a plant or animal better suited for
their environment.
#5. _______________________________________________- the ability of organisms that are best adapted to survive
and reproduce . Those that are less well adapted will not survive.
________________________________________________ - Eventually, over generations and time, new species will
evolve from older forms by natural selection of better adapted forms.
Evidence for Evolution
A. The _______________________________ Record
Fossil: the remains or evidence of past life recorded in rock. (molds, impressions, bones, shells, teeth,
preserved in ice, etc.)
1. Fossils are found most often ____________________________________________ rock.
2. Relative age can be determined by the fossils position in the layers. The oldest fossils are found
_________________________________ the younger ones.
3. ______________________________________________ dating uses the principal of radioactive dating
The half-life of known radioactive compounds never changes.
(ex. Carbon 14 found in bones and shells can determine their actual age in years).
Ex. Fossil remains clearly show the gradual evolution of the modern horse.
B. Comparison of Similar Anatomy or Structures
1. _________________________________________ structures - those that
appear to have come from a common ancestor. These indicate
that species are related. Ex. Bats wing, human arm and whale
flipper bones.
2. _________________________________________ structures - those that are used for the same function but are not
similar. These indicate species are not related.
3. ________________________________________ structures – those that no longer serve a useful function
Ex. Human appendix, tailbone (coccyx)
C. Comparative Embryology
Comparative Embryology – examination of differences and similarities in
__________________________________development. ex. Comparison of bird, fish and
early human embryos
D. Biochemical Comparisons
Recent developments (Human Genome Project) have allowed for the comparison of ______________ from
different species and groups within species. This new evidence is the strongest yet that
consistently supports accepted evolutionary theory.
E. Speciation
New species will arise more quickly if they are _________________________________________ isolated. Natural
barriers such as mountains, deserts, rivers or landslides can separate members of a population. If they
can no longer ____________________________________________ they may change enough by natural selection to
become a separate _______________________________. (ex. Darwin’s finches)
The loss of the ability to interbreed is called _________________________________________ isolation. Sometimes
this is caused by changes in reproductive organs such that the offspring will not ___________________________.
Sometimes this type of isolation is caused by changes in courtship behavior or the timing of mating
cycles.
Speciation---Geographic isolation of populations----Can lead to Reproductive isolation of
population ----Can lead to New Species (unable to breed when together)
Geographic Isolation- Members of a population may become isolated from one another by geographic
boundaries like mountains, rivers or even oceans
Evolutionary Time Frames
A.________________________________________________: species descend from a common ancestor gradually as the
change in minor ways over a long period of time.
B. ________________________________________________a newer theory developed by Stephen Jay Gould states that
species remain fairly constant over long periods of time until a great change in their environment cause
relatively rapid speciation.
_________________________________________Evolution- unrelated
species become more similar as they adapt to the same
environment.
________________________________________ Evolution- related species
become more different from each other. Also called adaptive
radiation.