Answer:
Dissimilar organisms might have evolved from a distant, common ancestor.
Explanation:
First of all we should know species. Species is considered as a basic unit of taxonomic classification of an organism.
Initially, the scientists are agreed on this phenomenon that all distinct species are evolved gradually from common ancestor. Today, the species which are different from each other just like hummingbirds, humans and whales are from the same ancestor but with the time passage genetic mutation occurs and at the end dissimilar organisms we can see in our environment/surroundings.
Because there are several factors that determine weight loss or gain and reducing calorific intake is just one of them (for reducing weight loss). Other factors that should be considered is exercise. Doing regular exercise ensures that the metabolic rate of the body is increased so much of the calories are burned even after intake. Having a lower metabolic rate can result to increased weight gain even with low calorie intake.