A group of organisms that possess similar genes and traits which no other group possesses
Species
A trait that helps an organism survive and reproduce
Adaptation
An allele that is always expressed
Dominant
The remains of an organism, often its bones that are left after it has died
Fossil
A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.
Natural Selection
Different forms of a gene (one from mother and one from father)
Allele
An organism's physical surroundings, such as food supply, soil, weather, water, trees, and mountains
Environment
An allele that is masked when a dominant allele is present so it is NOT expressed
Recessive
What layer would the oldest fossils be found in?
The deepest layer
Can Natural Selection occur if there is no genetic variation?
NO
An organism's physical appearance, or visible traits.
Phenotype
collection of all the genes
Genotype
If an organism has both the dominant and recessive allele for a trait in its genotype, which trait will the organism show in its phenotype?
Dominant
What type of rock are fossils found in?
Sedimentary rock
Natural selection is occurring
Slight differences in an organism's traits that are considered normal
Genetic Variation
The factors in an ecosystem that make it hard to survive and reproduce (food, predators, temperature, mates).
Environmental pressure
Are dominant genes always beneficial?
no
Explain how some fossils show species in lower layers that we don't see today.
The bones were fossilized and preserved.
List two events that could trigger the process of natural selection
-Environmental changes
-Predators
Are dominant genes always the ones with the highest frequency in a population?
No, dominant genes aren't always the right trait for survival.
A scientist who studies fossils
Paleontologist