Some fossil snakes have remnants of hip bones and legs even though these animals had no legs. These remnant structures are best described as:<u> vestigial structures</u>.
Vestigial structures are organic structures that do not appear to fulfill any important biological function in the organism that possesses them.
These structures are preserved as an inheritance of the evolutionary process, because at some point in the history of evolution an ancestor of the current species had that structure.
These types of structures, which can be bones, organs, structures in the skin or any other part of the body, no longer offer any meaningful function for the body.
The presence of vestigial structures in animals is considered proof that evolution and natural selection exists.
Therefore, we can conclude that some fossil snakes have remnants of hip bones and legs even though these animals had no legs. These remnant structures are best described as vestigial structures.
These microbial infections that are acquired by hospital patients as they are being used as the compromised host are the nosocomial infections. These type of infections are primarily caused by bacterial pathogens entering the patient's body and mainly causes urinary tract infection, pneumonia, and other illnesses.
Natural selection is the idea that species that acquire adaptations favorable for their environment will pass those adaptations to their offspring. Eventually, only individuals with those favorable adaptations will survive.