Diseases is the first answer
Second is lives
Infection is the invasion of an organism's body tissues by disease-causing agents, their multiplication, and the reaction of host tissues to these organisms and the toxins they produce. Infectious disease, also known as transmissible disease or communicable disease, is illness resulting from an infection.
Humans are more closely related to hogs than hogs are to guinea pigs.
Explanation:
The difference in the amino acid sequence of a protein is used to know the relation between organism i.e. how closely they are related.
It is known that proteins are the result of DNA sequence ie genes of the organism.
The gene or protein is compared between organisms to understand the evolutionary evidence and similarities between them.
The less is the difference the more is the two organisms closely related as in the case of hog and human which have only 1 amino acid difference in their insulin enzyme. While guinea pig is having a difference of 17 amino acids so it is expected to be distantly related.
These relations helps the scientist to resolve the issues of crisis say insulin. They zero out the possibility of extracting the enzyme genes of possible organism and increase the yield.
Oceans will increase in temperature due to global warming. This will adversely effect cold water species such as the humpback whale and increase the territory of larger warm water predetors like sharks.