2, because a theory is not a law that can not be changed, and new evidence can change a theory.
The main structural difference between LDL and HDL is their compositions. Approximately 50% of the weight of an LDL particle is cholesterol and only 25% is protein. High-density lipoprotein particles, on the other hand, consist of 20% percent cholesterol by weight and 50% protein.
Living organisms use two major types of energy storage. Energy-rich molecules such as glycogen and triglycerides store energy in the form of covalent chemical bonds. Cells synthesize such molecules and store them for later release of the energy.
Claim: Whales evolved from land mammals to water mammals.
Evidence: The first whales evolved over 50 million years. One of the first whales, such as Pakicetus, were land animals with long skulls and carnivorous teeth, much like many adaptable land mammals back then and today.
