Evolution :).
Descent with modification helps to explain anatomical similarities among certain species. The bones of the forelimbs of humans, cats, and bats (you can add in penguins, alligators, and more) are used in different ways but have similar structures.
The best explanation is that these animals have a common ancestor. With new generations, new species emerged by natural selection from different populations, and with this, the bones become better for different tasks.
The forelimbs and other such structures with anatomical similarities due to a common ancestor are called homologous structures.
You must pack food that has high concentrations of fat and protein. Food like granola bars and canned meat are a good source of energy and heat. This is because the body breaks this food down easily converting it into usable energy. Though some people would suggest that you pack food that are high in carbohydrates, fats and proteins are long-term sources of energy that you would need for your hiking trip.
If the farmer were to breed both of the two different types of cattle he would have a hybrid type of new cattle with both traits :)
