Answer: The primary hypothesis for extinction of mammoth was considered to be hunting by humans. A group of scientist thought that mammoth did not had genetic diversity until it was prooved as one large homogenous group. Hunting by humans were kept on the first place leaving the other factors like climatic change and disease behind. But the reality was something else, mammoth were divided into two groups, out of these two one group died before the appearance of the humans.
sea creatures and fish may lose their homes because one, they live their, and two, animals they may eat live there, so if their food leaves, they will die out or they might leave.