Biology - - 30 why is it rare to find fossils of animals from before the cambrian period? what about these animals makes it rare for them to form fossils? (answer both questions as soon as possible ! )

In general, are there any major differences that you can see? explain

Which of the following best describes the expensive tissue hypothesis? brains require more energy, so the gut had to be reduced, and larger brains and tool use led to higher quality diets. increasing body size means that homo neanderthalensis had to include more fat in its diet. brains require more energy, so the gut had to be reduced as brains got bigger. brains require more fat, so the gastrointestinal viscera (gut) had to expand, and hands were needed to acquire more food.

What best describes emerging scientific ideas