made up of all the fossils ever discovered on Earth Flashcards
Fossil record
Made up of all the fossils ever discovered on Earth
Fossil record
represents only a small fraction of all the organisms that have ever lived on Earth
incomplete
the remains or evidence of once-living organism
fossil
an organism dies and is buried by sediments, then minerals in the water replace the organisms original material and harden into rock
Mineralization
a fossil forms when a dead organism is compressed over time and pressure drives off the organism’s liquids and gases
carbonization
the impression of an organism in a rock
mold
a fossil copy of an organism in a rock
cast
is the preserved evidence of the activity of an organism
trace fossil
Determining the age of rock layers
Relative-age dating
determine a rocks actual age
absolute-age dating
Unstable isotopes in rocks change into stable isotopes over time
Radioactive decay
the time required for a quantity to reduce to half of its initial value
half-life
a chart that divides earth’s history into different time units
geologic time scale
the longest time units on the geologic time scale
eons
occurs when the last individual organism of a species dies
extinction
occurs when many species become extinct within a few million years or more
mass extinction
volcanic eruption, meteor impact, etc.
sudden changes
tectonic plate movement, sea level change, etc.
gradual changes
the change over time in populations of related species
biological evolution
a person who studies plants and animals by observing them
naturalist
a explanation of the natural world that is well supported by evidence
theory
the most recent species from which the species are descended
common ancestor
a slight difference in an inherited trait of indivisual members of species
variation
the process by which populations of organisms with variations that help them survive in their environments live longer, complete better, and reproduce more than those that do not have the variations
natural selection
an inherited trait that increases an organisms chance of surviving and reproducing in its environment
adaptation
an adaptation that enables a species to blend in with its environment
camouflage
the resemblance of one species to another
mimicry
the study of chemical process in living things
Biochemistry
the breeding of organisms for desired characteristics
selective breeding
the study of similarities and differences among structures of living species
comparative anatomy
body parts of organisms that are similar in structure and position but different in function
Homologous structures
body parts that perform a similar function but different in structure
analogous structures
body parts that have lost their original function through evolution
vestigial structures
the science of the development of embryos from fertilization
embryology
a pouch that all vertebrate embryos have at some point in their development
pharyngeal pouch
the study of gene structure and function
molecular biology
how a kind of plant or animal species is created
speciation
