Changes

=== Variable intake ===

=== Variable intake ===

Not all living things do have ¹⁴C:¹²C ratios the same as the atmosphere. For example it is well known that carbon dating cannot be used on many types of marine life due to reservoirs of "old" carbon held in sedimentary rocks. This problem is especially severe in shellfish or anything that eats shellfish; it is not unusual for freshly-killed seals to be dated as several thousand years old.

Not all living things do have ¹⁴C:¹²C ratios the same as the atmosphere. For example, it is well known that carbon dating cannot be used on many types of marine life due to reservoirs of "old" carbon held in sedimentary rocks. This problem is especially severe in shellfish or anything that eats shellfish; it is not unusual for freshly-killed seals to be dated as several thousand years old.

{{QuoteBox|...various plants have differing abilities to exclude significant proportions of the C-14 in their intake. This varies with environmental conditions as well. The varying rates at which C-14 is excluded in plants also means that the apparent age of a living animal may be affected by an animal's diet.  An animal that ingested plants with  relatively low C-14 proportions would be dated older than their true age."<ref>Nondestructive Testing (NDT) Resource Center, [http://www.ndt-ed.org/EducationResources/CommunityCollege/Radiography/Physics/carbondating.htm Carbon-14 Dating"]</ref>}}

{{QuoteBox|...various plants have differing abilities to exclude significant proportions of the C-14 in their intake. This varies with environmental conditions as well. The varying rates at which C-14 is excluded in plants also means that the apparent age of a living animal may be affected by an animal's diet.  An animal that ingested plants with  relatively low C-14 proportions would be dated older than their true age."<ref>Nondestructive Testing (NDT) Resource Center, [http://www.ndt-ed.org/EducationResources/CommunityCollege/Radiography/Physics/carbondating.htm Carbon-14 Dating"]</ref>}}