Walking on Two Feet

Our ancestors have existed for millions of years and because of evolution they evolved into us, but when did they start walking on two feet and why? There are many theories about why our early ancestors began walking on two feet and each have a large amount of evidence so it is hard to decide which theory is correct. Here are three theories with all the supporting evidence that has been found so far.

1. The first theory is that we the males needed to carry more food in order to attract females. At this time it would have made sense that the male that can gather the most food is more likely to mind a mate because he has food to give to the female and all the children they might have. The males that have not as much food wouldn't be able to feed the females and all their children. It would be much easier to carry heavier loads when standing upright than on all fours which would pose a viable reason as to why humans started walking upright.

2. Hunting. Our early ancestors had to get all their food by hunting or farming (which I think came much later) they couldn't go down to the local supermarket and buy their food, they actually had to hunt for it. When early humans hunted it would have been really hard to catch an animal crawling on all fours so humans might have started walking on two legs to catch the animals. 

3. The third and final theory is that they needed to use more tools and they couldn't do this while on all fours. If they were walking on their two legs then their arms are free to carry tools. 

These are all very viable theories with good reasoning and supporting evidence. It could be all the theories combined to be the reason they started to walk on all fours, but really we'll never know.