Answer:
Paleontologists didn't have the technology in that time to get a good estimation on the events. Back then, they had to rely on natural sources "markers" that made the estimations. Those estimations weren't accurate. Today's measures are accurate.
Answer:
Proteins are the major 'working molecules' within every organism. Among their many jobs, proteins catalyse reactions, transport oxygen and defend organisms from infection- like a doctor for organisms. The precise shape of each protein, and its genes, along with the amino acids it contains, determines what it does, some develop different traits and they may also copy traits of related organisms, which means some organisms may create more protein depending on their traits.
Answer:
often do not contain acetylated lysines in their histone tail
