Final Review

Carbon-14 is formed in the atmosphere by radiation

Carbon-14 is absorbed by plants exactly like it absorbs other isotopes of Carbon

When anything living dies, the percentage of its Carbon that is Carbon-14 will be about the same as the percentage of Carbon in the atmosphere that is Carbon-14

After anything living dies, the percentage of Carbon-14 that remains in it will decrease by 10% every half-life

Two C-14 half-lives, after an organism dies, only 25% of the Carbon-14 that was in it when it died will remain.

The rock being tested in the pink layer would be estimated to be over 4 Billion years old

In order to confirm the age of the rock being tested scientists would also use Carbon 14 dating on it

The fossils in the blue layer would be presumed by scientists to be younger than the rock tested in the pink layer

U-238 dating could be used to date the fish skeleton in the pink layer

While U-238 dating could not be used to date the fish skeleton in the pink layer, the age of the rocks in the pink layer could help scientists estimate the date of the fish skeleton buried nearby.

The diagram above is a example of a phylogenetic tree

According to the diagram above, sharks have bony skeletons

Many scientists believe bony fish are more closely related to sharks than lampreys

One purpose of the diagram above is to propose how different species may have been related to common ancestors

Scientists rearrange the diagram above when new evidence shows two species have more important similarities than previously known

Mutation is caused by a random change in a DNA base in a gene

Mutation creates a new allele in the gene that was mutated

After a mutation both the old allele and the mutated allele will both exist in the population

If a mutation in a mouse causes a protein not to make a dark color pigment, it may change a mouse from a R^D to R^L genotype, which might make it a lighter colored phenotype.

If a population of mice all have the same genotype, natural selection can help the species adapt and change to new threats in the environment

If a new allele changes a mouse's appearance so that it can hide better from predators, that allele is likely to become more common in the population

Both lines above represent the perch height of brown anoles

Both lines above represent the perch height of green anoles

The top line represents the perch height of green anoles after brown anoles are brought to their island

The bottom line represents the perch height of green anoles on islands brown anoles are never introduced to

The process scientists hypothesize caused the green anoles to climb higher in the bushes is competition with brown anoles

Pine Cay and Water Cay are islands in the Atlantic Ocean

The graphs above show scientists measurements of brown anoles

Scientists took measurements before and after Hurricanes Irma and Maria hit the islands

According to the left graph, the scientists found that on average, scientists found the anoles they measured after the hurricanes had longer front legs than anoles with the same length measured before the hurricanes

The data from Pine Cay would support the hypothesis that longer front legs helped anoles survive the hurricanes better than the data from Water Cay

According to the right graph, the scientists found that on average, scientists found the anoles they measured after the hurricanes had shorter hind legs than anoles with the same length measured before the hurricanes