How do the chromosomes in gametes produced during meiosis differ from chromosomes in somatic cells produced during mitosis?

In general, characteristics that an organism survive and reproduce become more common over time. what mechanism of evolution causes this?

Where substance is produced during cellular respiration

Zoo geographic regions are characterized by the presence of specific groups of animals these regions are determined by the taxonomic or phylogenetic relationships of animals. the map shows the zoogeographic regions proposed by the naturalist alfred russel wallace in 1876. the similarities of organisms in which two areas numbered above provide the best evidence for common ancestry between the organisms in both locations ?