Science Test Chapter 6
Terms in this set (27)
a group of organisms that can produce offspring
preserved remains or traces of an organism that lived in the past
traits that help an organism survive and reproduce
the gradual change in a species over enormous spans of time
a theory that has been well-tested with a wide range of observations
the prosses by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of that species
There are variations in populations.
Those variations can be favorable.
More offspring are produced in each generation that can survive.
Those offspring that survive and reproduce have the favorable variations.
Over time, small changes accumulate and populations change.
fossils, early development, body structure, DNA
similar structures that related species have inherited from a common ancestor
lost all or most of their origional function through evolution
diagram showing how organisms might be related
new species form when...
a group is isolated from its species for a long enough time for changes to occur
fossil formation process
1) organism dies in or near water
2) sediments cover the body
3) over millions of years, the sediment become rock
4) the rock errodes exposing the fossil
petrified fossils/ premineralization
formed when minerals replace the remains, turning them to rock
molds and casts
formed when hard structures dissolve in sediment leaving a hollow space in which minerals form a cast
ice, tree sap
use to determine if one fossil is older than another
radioactive (carbon) dating
used to determine the actual age of a fossil
no members of the species are still alive
geological time scale
a calander of the earth's 4.6 billion year history
fossils cant tell...
causes of mass extinctions, climate changes
slow and constant gradual changes over time
change occurs in spurts, explains gaps in fossil record