Fossils back then were different than the ones today.
so many organisms share so many detailed structures.
The more closely related species are the more of the same DNA sequences they have
Animals that are similar and are closely related tend to be in the same regions, because evolutionary change is driven by part by geographical change
when organisms begin to be isolated by physical barriers, they take their own evolutionary courses.
(example with Finches on Galapagos Islands)
Darwin observed that different species of finches on separate Galapagos islands were not only similar to each other, but were also similar to the species found on the south American main land.
He concluded that all the Galapagos finches were descendent of the Finches from the Main Land, and changed over time to be more fit for their environments.
DDT killed 95% of mosquitos on the first application... Those that survived reproduced and passed on their genetic resistance to the insecticide. Within a year, DDT was killing only 49% of the mosquitos, and it continued to drop.
The genetic makeup of the mosquito population changed because of the selective pressures caused by the use of DDT
Having similar bone structures, or same bones structures but in a different shape/form as other species, and are used for same reasons..
this is comparative anatomy because you are comparing bone structures to find out how species can be similar
relationships between organisms & classification levels:
Broadest to narrowest
have same class= have same class name
Same phylum= not same species
Same genus= same phylum
same genus name= are very closely related
scientific naming system that determines which animals are closely related and which are not.
Written in italics
uses 2 part name to name species