What is an adaptation? What happens if the adaptation has a positive affect?

The galapagos island contain 13 species of finches four of the species are seen here it is believed that all of the species had one common ancestor and overtime

Which characteristic should describe all evidence collected by a scientist? true obvious objective subjective

During crossing-over, a. genetic material is exchanged between nonsister chromatids, resulting in new combinations of alleles. b. nonsister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. c. one homologous chromosome of a tetrad is exchanged with another tetrad, resulting in new combinations of alleles. d. sister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. e. genetic material is exchanged between sister chromatids, resulting in new combinations of alleles.