I would say that the kidneys purpose is to filter waste material from the blood primarily to remove waste fluid from the blood and leave just the right of salt and minerals in the blood and remove the waste fluid which is known as urine.
<span>This variation be justified by:
</span>Migration to an environment different from their birthplace, and adaptation to the available food, ultimately leading to speciation. because <span>birds use their beaks to eat.</span>.
The trees dont take in co2 cause there are none cutting off the oxygen cycle