Topic 5.1 Evidence for Evolution Flashcards
Evolution
Change over time. In living organisms this change refers to the heritable characteristics of a species
Heritable Characteristics
Encoded for by genes and may be transferred between generations as alleles
Biological Evolution
A change in the allele frequency of a population’s gene pool over successive generations
Comparative Anatomy
Comparative anatomy of groups of organisms may show certain structural features that are similar, implying common ancestry
Factors causing speciation
Genetic variation
Different geographical and ecological conditions
Speciation
The evolutionary process by which two related populations diverge into separate species is called speciation
Genetic divergence is caused by…
geographically separated species that will experience greater divergence the longer they are separated.
In addition, species will diverge to the point where they will no longer be able to interbreed even when put back in the same environment.
eg. jaguars, cheetahs, lions, tigers etc all come from a common large cat ancestor
Radioactive Dating
This method involves comparing the ratio of radioactive isotopes in the fossil to that found in the atmosphere today