Question

Which of the following is the relatively most accurate method for dating fossils?
A. Potassium-argon method
B. Uranium-lead method
C. Electron-spin resonance method
D. Radio-carbon method

Answer 1

Hint: Fossil dating is the science of determining the age of fossils using a number of techniques like radioactive isotopes, paleomagnetism, etc. It is also referred to as geochronology which attempts to derive absolute age data of all the fossil assemblages and determine the geologic history of Earth.

Complete answer:
1. Potassium-argon method: It is a radioactive dating technique used in geochronology and archaeology. It is based on the measurement of the product of radioactive decay of an isotope of potassium into argon. Quickly cooled lavas make nearly ideal samples for potassium-argon dating.
2. Uranium-lead method is one of the oldest and most refined of the radioisotopic techniques.
3. Electron-spin resonance method is used to date recently formed material like carbonates, tooth enamel, or material that have been previously heated like igneous rock. It measures the number of unpaired electrons in crystalline structures that were exposed to natural radiation previously. The age is estimated by measuring the amount of dosage radiation since the time of its formation.
4. Radio-carbon dating is a method that provides objective age estimates to a carbon-based material that originated from living beings. It can be estimated by measuring the amount of radioactive carbon present in the sample and then comparing it with a standard.

The correct answer is (C) Electron-spin resonance method.

Note:
- The purpose behind fossil dating is to understand the evolutionary relationships among and within the species. It helps us to understand the evolution and thus the origin of life better.
- Stanley Lloyd Miller was an American chemist and biologist who was known for his studies into the origin of life.