Pollution is always a good way to go but you don't have to do air pollution you can do water pollution or both air and water pollution.
Crossing-over is the exchange of genetic material between homologous chromosomes. It results in new combinations of genes on each chromosome. When cells divide during meiosis, homologous chromosomes are randomly distributed to daughter cells, and different chromosomes segregate independently of each other.
These animals were living in an environment with a warm climate that results in changing sea levels. These conditions create a lot of shallow inland seas allowing these animals to thrive. The Cretaceous period is the last period of the Mesozoic area where new groups of mammals, birds, and flowering plants appeared on Earth.
UHHHH I think it’s F because organisms are all different therefore can’t have the same patterns?