Darwin studied actual birds on the galapagos
islands instead of using a simulation, as you did in
this lab. studying natural selection in the field can
be challenging. list at least three possible
challenges darwin might have faced.

Natural selection was proposed by Darwin.

Explanation:

He stated that when the limiting factor exist then different species of organism have to compete with each other and the species that is able to survive the competition stays and adapt themselves according to the condition.

Darwin studies natural selection in birds of Galapagos island. He must have faced difficulties and they are: complex environment is difficult to study, it may take longer to study different generations of a population and the birds may be dependent on other species that also might have evolved.

endo:

regulates body hormones, aldosterone, vasopressin

neural:

signal, regulates body using electric signals, reflex

endo has to do with hormones; aldosterone and vasopressin are both hormones. i also had this question and got it right : d

a symbiotic relationship with the mitochondria