Evolution

alleles

different alleles result in different traits forming, or different phenotypes

an evolutionary force that causes a particular phenotype to be more favorable in certain environmental conditions

Individuals that are ‘fitter’ due to favourable traits (i.e. better adapted to the environment) will survive.

The individuals with favourable traits will contribute more to the next generation than those that are less fit.

variation exists in all living things

there is an environmental pressre / selection pressure

due to the environmental pressure, some organisms will have the advantageous trait

the advantageous trait enables an organism’s survival

the organisms that survive reproduce, passing their advantageous trait onto their offpsring

overtime, the allele frequency of the advantageous trait increases, and the majority of the population will have the trait

bacteria mutates very quickly; when a bacteria mutates, it can become resistant to bacteria. This resistant bacteria can duplicate rapidly, making majority of the population resistant.

Radioactive dating is a scientific method to determine the age of materials, such as rocks, fossils, and artifacts, by measuring the decay of radioactive isotopes.

• It relies on the principle that unstable, radioactive atoms (parent isotopes) decay at a constant rate, transforming into stable atoms (daughter isotopes) over time. • By comparing the ratio of parent to daughter isotopes and knowing the rate of decay, scientists can calculate the age of the sample.

absolute

a geologic principle that states in an undisturbed sequence of rock layers, the oldest layers are at the bottom and the youngest layers are at the top

it relies on the principal of natural deposition, where new sediment and rock materials accumulate upon older, or already existing rock. Therefore, each new rock layer (if undisturbed) must be younger than the one below it.

any geologic feature, such as a fault or an igneous intrusion, that cuts across a sequence of rock layers is younger than the rock layers it disrupts

the dating is RELATIVE. It does not give you any numerical ages. Fossils found in lower layers are older than fossils found in higher layers according to the law of superposition.

a type of fossil from an organism that lived for a relatively brief period of geologic time, is abundant, easily recognisable, and has a wide geographic range.

scientists look for INDEX FOSSILS across different locations. If the same index fossil is found in layers of rock in different places, they can be correlated, and the layers can be said to be similar ages.

a timeline of Earth’s history developed by geologists that breaks up history into eons and eras

the remains of organisms that have been preserved over time.

• Evolution! Organisms increase in complexity through mutations DNA, multicellularity and adaptation through the process of natural selection. These are all process of evolution.