Subject Experts Solutions for Exercise 4: Assertion & Reason

Assertion : Ginkgo biloba is a living fossil.

Reason : Organism which have persisted and remain unchanged for the past several million years while their relative disappeared.

Assertion : From evolutionary point of view, human gestation period is believed to be shortening.

Reason : One major evolutionary trend in humans has been the larger head undergoing relatively faster growth rate in the foetal stage.

Assertion : The theory of survival of the fittest is widely misunderstood.

Reason : Evolution does not always increase the chances of a species survival and species do not survive when such chances happen rapidly.

Assertion : All primates have a common ancestry.

Reason : The most primate was shrew like animals.

Assertion : Most evolutionary trees place information about the pattern of relationship among organisms on the vertical axis and information about time on the horizontal axis.

Reason : An evolutionary tree depicts the pattern of relationships among parents and their offsprings.

Assertion : Darwin's finches show a variety of beaks suited for eating large seeds, flying insects and cactus seeds.

Reason : Ancestral seed-eating stock of Darwin's finches radiated out from South American mainland to different geographical areas of the Galápagos Islands, where they found competitor-free new habitats.

Assertion : Atavism is the reappearance of disappeared ancestral characters.

Reason : Third molars and hair on body are examples of atavism.

Assertion : Petrified fossils contain hard parts of organisms.

Reason : Moulds and casts lack the remains of organisms.