What two things do scientists use to study the evolutionary trends in vertebrates

All individuals have two alleles for a given trait. according to mendel's these alleles are passed down one each from both mother and father.

Svetlana and her mother are very similar. both have blonde hair, a love of scrapbooking, blue eyes, and a thin nose. which statement  most likely  describes svetlana’s traits? svetlana inherited her love of scrapbooking from her mother, but her blue eyes come from her environment. svetlana inherited her blue eyes from her mother, but her love of scrapbooking comes from her environment. svetlana inherited her thin nose from her mother, but her blonde hair comes from her environment. svetlana inherited her blonde hair from her mother, but her thin nose comes from her environment.

Explain how organisms could be harmed by high levels of salt from roadways?