Evolution: The History Of The Earth And Life Flashcards
How in an ion created?
If the number of electrons change
How is a new element produced?
When its number of protons change
How is a neutron created
If the neutron number changes
What causes an element to be radioactive
If the diff. # of neutrons makes the isotopes unstable, the nucleus will disintegrate. Unstable nuclei make elements unstable
What are the radioactive particles
Alpha a and Beta B
What is an index fossil
Fossils of organisms that existed only during specific spans of time and lived in large geographic areas
How is radiometric dating measured
By observing the breakdown of isotopes in an element over time; half lives
Amount of time it takes for half an unstable isotope to decay
Half life
One half life is
5730
__________ involves comparing the ages of different fossils according to their order in rock layers
Relative dating
__________ uses measures of half lives to determine the actual age of a material
Radiometric dating
Time eras in order from most recent to farthest back in time
Cenozoic, Mesozoic, Paleozoic, Precambrian
What is the most wildly excepted hypothesis of earths orgins
The solar system formed a cloud of dust and gas called a nebula. Gravity pulled the material in the nebula together into a large disc that circled the sun. Over millions of years, this material attatched to one other, gathering and forming planets.
Early earth was
Molten
Miller-Urey experiment showed
That organic molecules could have formed on the early earth from inorganic molecules
Meteorite hypothesis suggests
That organic molecules might have arrived on earth through meteorites or may have been present when the earth was formed
Early cell structure: Bringing together organic molecules theory
Hot gases rising from the oceans floor formed rocky structures when met by cold water. Organic molecules settled into the nooks on these structures, possibly forming the first cells
Early cell structure: forming a lipid membrane hypothesis
The membrane enclosed spheres that lipid molecules form into may have at some point formed a double membrane. These membranes could then form various organic molecules, and later give rise to the first true cells.
Cyanobacteria:
Bacteria that conduct photosynthesis
Endosymbiosis:
A relationship in which one organism lives within the body of another, and both benefit.
Endosymbiosis is based on the fact that
Mitochondria and chloroplasts have their own DNA
Sexual reproduction & multicellular life
Cells living close together to benefit one other may have evolved into multicellular life. Sexual reproduction offers genetic variation, making offspring less susceptible to the same diseases, therein by increasing the offsprings chance of life and reproduction
What type of cell evolved through endosymbiosis
Eukaryotic
Biogenesis:
All living things come from other living things
Spontaneous generation:
The belief that living things could arise from nonliving things
Redi’s experiment
Flies
Fossils
Traces of organisms that existed in the past.
Catastrophism:
The idea that past natural disaster shaped land forms and caused species to become extinct in the process
Gradualism:
The idea that landforms were shaped by very slow changes over a long period of time
Favored theory of geologic change that helped develop Darwin’s theory
Uniformitarianism: the idea that the same process which shaped landforms in the past still shapes them today.
One example of evidence from Darwin’s travels that supports an ancient earth:
His finding of marine fossils up in the andes mountains
An adaption Darwin noticed
Different beaks of finches
Artificial selection
Human breeding for best qualities
Natural selection
Most favorable qualities live while others die off
