If human civilization had never developed on earth, would there be a greenhouse gas?

Me with these questions if you’re it sure don’t answer

Why is excretion necessary to maintain homeostasis?

Question 1 of 102 pointswhich best describes adaptive radiation? oa. geographical isolation caused by an adaptationob. biodiversity resulting from few ancestorsoc. a decrease in the rate of speciationd. adaptations that organisms teach each other