Test: Origin & Evolution - 2 - UPSC MCQ

At the time of origin of life free O2  was absent, so first life was anaerobic. In the primitive atmosphere free oxygen was present but complete oxygen consumed in composition so primitive atmosphere of earth was reducing. Oxygen was reproduced by photosynthesis and atmosphere converted in oxidizing. 

Sudden change in general or genetic information due to some factor is called mutation. It is same as evolution but at a faster rate so it has been named mutation instead of evolution. The cause of mutation are change in DNA, changes in chromosome, changes in gene. 

The correct option is B.
Located 906 km (563 mi) west of continental Ecuador, the islands are known for their large number of endemic species that were studied by Charles Darwin during the second voyage of HMS Beagle. His observations and collections contributed to the inception of Darwin's theory of evolution by means of natural selection.

The correct option is B.
The science of extraterrestrial life in all its forms is known as astrobiology. Since the mid-20th century, active ongoing research has taken place to look for signs of extraterrestrial life.Astrobiology, formerly known as exobiology, is an interdisciplinary scientific field concerned with the origins, early evolution, distribution, and future of life in the universe. Astrobiology considers the question of whether extraterrestrial life exists, and if it does, how humans can detect it.

To say that Darwin's journey aboard the Beagle and time spent at sea was not life-changing would be an understatement. In 1831 – at the age of 22 – Charles Darwin was given the opportunity of travelling aboard a survey ship, HMS Beagle, as a naturalist.

The book written by Weisman is Germ fluid. Alan Weisman was an American author, professor and journalist.

In the embryo of all vertebrates, the presence of gills slits supports the theory of recapitulation. This supports the evolution sequences of various organisms groups.

The correct option is B The dead and decomposing matter in the soil gets suppressed in the lower strata of the soil which turn into fossils due to pressure and temperature in the lower strata of the earth crust. Age of fossils can be detected by the quantity of radioactive carbon compound. Radiocarbon dating is used for determining the age of an object containing organic material by using the properties of radiocarbon (14C), a radioactive isotope of carbon. 
The radiocarbon dating method is based on the fact that radiocarbon is constantly being created in the atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting radiocarbon combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire 14C by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and from that point onwards the amount of 14C it contains begins to reduce as the 14C undergoes radioactive decay. Measuring the amount of 14C in a sample from a dead plant or animal such as piece of wood or a fragment of bone provides information that can be used to calculate when the animal or plant died. The older a sample is, the less 14C there is to be detected, and because the half-life of 14C (the period of time after which half of a given sample will have decayed) is about 5,730 years, the oldest dates that can be reliably measured by radiocarbon dating are around 50,000 years ago, although special preparation methods occasionally permit dating of older samples.
 

Genetic drift is one of four factors
(mutation, migration, genetic drift, and natural selection) causing gene pools to change over time, and genetic drift is at the heart of several recent theories of evolution.