Single nucleotide polymorphisms (snps) are useful in epidemiology because:
a. it is a laboratory technique that permits manipulation of dna to determine gene function
b. their presence is evidence of a defect in dna replication, and therefore proof that a given disease is present
c. they may be located within or in close proximity to a gene, and may therefore serve in identifying carriers of a characteristic (including a genetic defect)
d. it is an approach to determine the location of a given gene, therefore speeding identification of the mechanism of the disease and confirming carriers of the defect

b. Their presence is evidence of a defect in DNA replication, and therefore proof that a given disease is present

Explanation:

Single nucleotide polymorphisms (SNPs) result from point mutations and correspond to the position where there is alternation of nucleotides A, C, G, T at a minimum allele frequency of 1% in a given population. SNPs can be present in both coding and non-coding regions of the genome. As a nucleotide alternation is the result of a defect in DNA replication and these defects cause syndromes and diseases; we can say that single nucleotide polymorphisms are evidence of a defect in DNA replication and therefore proof that a particular disease is present.

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.

fossil's are like over rated rocks like low key not gonna lie i don't get why we can't just call them old rocks like for real i mean i call my grandpa and grandma that smh