Evolution

not real, jesus made everything! (and i guess god did too) Origins of the Universe Origins of the Earth
 * Evolution **
 * Universe is expanding
 * **As light moves away from a given source (the earth) the wavelength increases and causes a __redshift__**
 * **Rate of expansion shows the approximate age of the universe, 5 billion yrs ago**.
 * __Big Bang__- the universe was concentrated into one super dense mass that exploded **.**
 * **Gravity pulled matter together to form stars and galaxies.**
 * Originally molten rock until the crust cooled.
 * Core still molten (radioactive)
 * Escaped gasses formed the atmosphere.

**Early atmosphere**

-Earth is able to maintain an atmosphere due to gravitational field -gases made up atmosphere were mainly expelled by volcanoes -list of gases:


 * Water vapor (H2O)
 * Carbon dioxide (CO2)
 * Sulfur dioxide (SO2)
 * Carbon monoxide (CO)
 * Hydrogen sulfide (H2S)
 * Hydrogen cyanide (HCN)
 * Nitrogen (N2)
 * Hydrogen (H2)

-had little or no free oxygen due to its highly reactive properties with the other elements


 * Variations, survival of fittest, reproduction**
 * **Natural Selection** is the process by which evolution occurs
 * variation exists in populations
 * those who survive will reproduce
 * next generation will have those "better" traits more often
 * **Coevolution**
 * evolution of interacting species in response to one another such as predator and prey, symbiotic relationships and competition
 * **Aritificial Selection**
 * selective breeding of domestic plants and animals desired for traits
 * ex. dairy cows, chickens, dogs and cats
 * Evolution leads to variation in species and the species that survive are able to produce

Evidence for evolution from Darwin: **

__Fossils:__ - Physical evidence of organisms not found on Earth today (digging deeper is going further back in time). - Helps determine the relationships of extinct and living species.

__Homologies:__ - Homologus structures. -Evolution predicts that an organism's body parts are going to be similar to their ancestors, not new features. (animal limbs may move in different ways, but they are similar in structure). -Homologies are an explanation for some biological theorys, but it doesn't exactly provide enough evidence for evolution.hysical evidence of organisms ot found on Earth today (digging deeper is going farther back in time). - Helps determine the relationships of extinct and living species.

__Genetic and molecular evidence:__ - Sources of variation = mutation, genetic recombination, crossing over, independent assortment, and fertilization.