7th Grade Science Natural Selection

Evolution

individuals with favorable traits are more likely to reproduce and pass thier traits to the offspring. Invidivuals with unfaborable traits die or leave fewer offspring

Natural Selection

the species evolves as the environment (nature) selects for individuals with favorable traits. In time there are more individuals with favorable traits.

Charles Darwin

Who lived during the 1800s. He believed organisms evolved by a process called natural selection. 

Competition

organisims produce more offspring than can survive. Therefore, individual organisms of a species must compete for limited resources

Fitness

describes how successful an individual is able to obtain resources, survive and reproduce

Adaptation

Individual organisms of the same species have different traits. The variety of traits is called diversity.

Survival of the Fittest

Individuals with more favorable traits are better suited to their environment.  These individuals outcompete those with less favorable traits.

Fossil

preserved remains or traces of once living organisms

Geologice time scale

a time scaled organized to when certain organisms lived on earth. Is based on the appearance and disappearance of life forms

Selective Breeding

process by which humans breed plants and animals for particular traits. takes place over relative short period of time

Adaptation

Feature common in population becuase it allows an organism to have some type of improved foundation

Petricifcation

result in organic material converting into stone or a similar substance. Petrified wood is best known example

Petrificiation Replacement

solid material fro organism is dissolved and repalced with another material. example - bones, shells, wood

petrificagtion permineralization

groundwater carries dissolved minerals into the pores and cavities of the organism. Original material preserved. example bones, shells, wood

Molds & Casts

mold - organism dies and there is no filling of the cavity.
Cast - organism dies and cavity is filled with minerals, sand, clay. many shells are fossilized like this

Carbonization

all plants and animal matter decays except carbon.
leaves a carbon film on the sedimentary rock
happens with many plants and fish

fossil resin (amber)

resin is excreted from injured plants or animal for protection
sticky residue captures insects and other vertebraes

Tar and Ice

Resin is also called amber
organism becomes trapped in tar and preserved.
freezing can also trap animals

trace fossils

provides indirect evidence of life.
footprints, tracks, burrows, feces, borings