Question

Which of the following is known as a living fossil?
A. Lepidosiren
B. Lepidosteus
C. Latimeria
D. Neoceratodus

Answer 1

Hint: The living fossil is an extant taxon that closely resembles organisms otherwise called only from a fossil record. To be considered as the living fossil, the fossil species must be old relative to the time of origin of an extant clade.

Complete step by step answer: Latimeria is a genus of the West Indian Ocean Coelacanth and the Indonesian coelacanth. A living fossil is defined as the living species that has no close living relatives and are much similar to the species found in fossils. Latimeria is one such living fossil. Living fossils mostly exhibit stasis over geologically long time scales. However, scientific investigations have repeatedly discredited such claims. The minimal superficial changes to living fossils are mistakenly declared as the absence of evolution, but they are examples of stabilizing selection, which is an evolutionary process and perhaps a dominant process of morphological evolution. Early analyses of evolutionary rates emphasized the persistence of a taxon rather than rates of evolutionary change. Contemporary studies have analyzed rates and modes of phenotypic evolution, but most have focused on the clades that are thought to be adaptive radiations rather than on those thought to be living fossils.
Therefore, the correct answer is option A.

Note: Ginkgo biloba is called the living fossil because all the other members of its group are now fossils. Ginkgo is used as a herbal remedy to treat many conditions. It may be the best-known treatment for dementia, Alzheimer’s disease and fatigue. It is also used to treat anxiety and depression.