As humans migrated throughout the world, populations encountered distinct pathogens, and natural selection increased the prevalence of alleles that are advantageous in the new ecosystems in both host and pathogens. This ancient history now influences human infectious disease susceptibility and microbiome homeostasis, and contributes to common diseases that show geographical disparities, such as autoimmune and metabolic disorders.
The limitations of using fossil in evolution theory are that fossils are rare and only show changes in bones of animals. In many environments the preservation of fossils is hard creating gaps in fossil records that can make identifying change very hard. And when changes present themselves they can be in many forms, such as changing in the soft tissue, coverage and thickness of hair, and changes in organs, all of which can not be preserved by fossilization.
I’m not sure what kind of answer you need but I hope this is sufficient. Hope this helps. Stay healthy and stay safe! :)
It helps to give solid evidence of natural selection. The idea is that there are a number of finches in the Galapagos Islands. These birds vary slightly in appearance, in the function of their beaks and in size. Two species can eventually alter themselves because of the environmental conditions they live in. Some traits will be passed on or developed in one group and not in the other or vica versa. These finches are remarkable in that it did not take long for the changes to take place. It is probably one of the strongest reasons for believing in natural selection, because only those birds who could adapt to change could easily pass on these advantages to their offspring. The relatively short period of time to enact these changes is what makes the this example so attractive.
A tsunami is associated a lot. Hope that helped dude! ( Or girl.)
