Ibps So Marketing Exam Template With Answers printable pdf download

IBPS SO Marketing Set

ENGLISH LANGUAGE

Directions: Study the following information carefully and answer the questions below:

Modern birds evolved from ground – dwelling reptiles as their increasingly refined parenting

skills led them into the trees, where they could better protect their young, proposes a researcher at the

University of California, Davis. This new theory, contradicts the two leading theories on the evolution

of avian flight. “The evidence indicates that a whole site of behavioral and physical traits, including

feathers and wings evolved along with improved parenting and brood care traits,”said James Carey, a

UC Davis demographer and ecologist.

Once the precursors to birds began to fly, the ecological interplay of flight and parental care

may have been mutually, continuing the evolution of both traits and accelerating the rate at which the

physical features of the modern bird were acquired. The origin of bird flight is a fundamental issue in

biology and in overall evolutionary theory. Many scientists point to the fossilized specimens of

Archaeopteryx as evidence that there was a transitional vertebrate species that developed during the

evolution from reptilian dinosaurs to birds. Furthermore, they suggest that the development of flight

may explain why bird – like dinosaurs avoided extinction.

Until now, there have been two basic theories on the origins of bird flight. The first, the

arboreal theory, is a tree to ground model, suggesting that bird’s primitive ancestors were tree

dwellers that leapt from branches. Through the ages, the ability to glide and later fly developed

because gliding slowed their fall to earth when they missed a branch. The second, the cursorial theory,

is a ground up model that suggest that birds evolved from four legged reptiles. According to the

theory, scales on these creatures gradually developed into front limbs with features that gave them

upward thrust when they ran and eventually enabled them to fly.

On the other hand, the parental care theory is consistent with both the physical and behavioral

changes that appear to have occurred as reptiles evolved into modern birds. Researchers suggest that

modern bird’s very early ancestors were reptiles that established and guarded their nests on the

ground, much like crocodiles. Over time these creatures developed hard – shelled rather than leathery

eggs and the ability to modulate their own body temperature in order to provide a more constant

environment for their young ones’ development. Scales evolved into feathers better camouflaging and

insulating the parents. In time these early ancestors of birds developed more advanced techniques for

caring for their young. They started to feed their young in the nest, pumping liquid food or placing

small food items in their mouths. They also began to produce fewer and more dependent offspring and

smaller eggs and began nesting in bushes. Some of these creatures became feathered and even more

elongated, enabling them to better manipulate their eggs and to ‘parachute’ from their tree nests to a

soft landing. Later they would develop the ability to glide and eventually fly by flapping their wings.

Carey hypothesizes that bird beaks also developed in the context of parental care. The beak, he

suggest, serves both as a point source of food for small hatchings in the same way the nipple is used to

feed mammalism young and also as the tool for sophisticated use because they weigh less than teeth

and so are better adapted for flight. He points out that flight provided these are historic ancestors of

birds with numerous advantages including the ability to safely place their young – high in trees and

cliffs, maximize the food sources through seasonal migrations and supply more and higher quality

food by expanding their foraging range.

He adds that fossil record, specifically Archaeopteryx, provides ample evidence that the evolution

of parental care was the main driving force behind the evolution of avian flight.

1. According to the parental care theory, which of the following is true about the very early

ancestors of present day birds?

a) They laid their eggs on the ground and tended to their young there

b) They stayed only on the ground and laid their eggs there

Install GK Digest Android App

Page 1

Ibps So Marketing Exam Template With Answers

Related Articles

Related forms

Related Categories