Evolution Test - 30

The Jurassic Period was the second segment of the Mesozoic Era. It occurred from 199.6 to 145.5 million years ago, following the Triassic Period and preceding the Cretaceous Period. The most important event in this period include dominance of reptiles, gymnosperms continue as dominant and origin of toothed birds (first birds). Hence option B is correct.

In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges and opens environmental niches. Adaptive radiation occurs in sexually reproducing population to create multitude new forms and not in predator free area, small and isolated populations and flightless and asexually reproducing populations. Thus, option D is correct and other options are wrong.

Homology refers to evolution of organisms in different directions from a common ancestry i.e., divergence. It leads to development of homologous organs that are adapted to perform different functions and have different appearance but share common basic structural plan and origin. 

Amphibians are absent in Galapagos islands as they could not leave the mainland and travel to the island by crossing saline water.

In evolutionary biology, convergent evolution is the process, whereby, organisms not closely related, independently evolve similar traits as a result of having to adapt to similar environments or ecological niches. Thus, option A is correct. Non random evolution occurs due to mating  that has not occurred due to chance, and therefore has had human interference. Thus, option B is wrong. In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges and opens environmental niches. Thus, option C is wrong. The process in nature by which, according to Darwin's theory of evolution, organisms that are better adapted to their environment tend to survive longer and transmit more of their genetic characteristics to succeeding generations than do those that are less well adapted is called natural selection. Thus, option D is wrong.

• Adaptive radiation is the relatively fast evolution of many species from a single common ancestor. It occurs when an organism enters a new area and different trait affect its survival. 
• An example of adaptive radiation is Hawaiian honeycreeper is small, passerine birds.
• They are closely related to the rosefinches in the genus Carpodacus. Their great morphological diversity is the result of adaptive radiation in an insular environment. 
• Hence, Hawaiian honeycreeper (birds) are an example of Adaptive radiation.
• So, the correct answer is 'Adaptive radiation '.

The Hardy-Weinberg principle assumes that the allele and genotype frequencies in a large population will remain constant from generation to generation in the absence of evolutionary influences like mate choice, mutation, selection, genetic drift, gene flow, and meiotic drive.

Hardy Weinberg law is applicable to genetic equilibrium. The Hardy-Weinberg equilibrium is a principle stating that the genetic variation in a population will remain constant from one generation to the next in the absence of disturbing factors. When mating is random in a large population with no disruptive circumstances, the law predicts that both genotype and allele frequencies will remain constant because they are in equilibrium. 

• The conditions to maintain the Hardy-Weinberg equilibrium are no mutation, no gene flow, large population size, random mating, and no natural selection.

• The Hardy-Weinberg equilibrium can be disrupted by deviations from any of its five main underlying conditions.
• Hence, Under which condition, Hardy Weinberg's law is violated Natural selection, Mutation and Immigration and genetic drift.
• So, the correct answer is 'All of the above'.