Adaptive radiation class 12

Hint: Due to natural selection, adaptive radiation is possible. Adaptive radiation is the evolution of a group of animals or plants into a wide range of organisms adapted to specialized lifestyles. In closely related groups that have formed in a relatively short period, it is best exemplified. Complete answer: The process of evolution of different organisms in a given geographical region is called adaptive radiation, beginning from a point and simply radiating to other areas or habitats. A striking example is the radiation of basal mammalian stock into forms adapted to running, jumping, climbing, swimming, and flying, starting in the Paleogene Period (beginning 66 million years ago). Australian marsupials, cichlid fish, and Darwin's finches (also known as Galapagos finches) are other examples. Australian marsupials, such as placental wolves and Tasmanian wolves, have evolved from a common ancestor and placental mammals show similarities with their corresponding marsupials. The modification of finch beaks on the island of Galapagos. Darwin's finches, which he discovered on the Galapagos Islands, are one of the most famous examples of adaptive radiation. On the island, he observed a variety of birds, all of which were created from a single seed-eating species which accidentally landed there. Therefore, birds with a variety of beaks have evolved because of the numerous feeding practices. Different birds with a difference in food availability formed distinct feeding habits tha...

The process of evolution in which new species are produced from a single point and radiate in different directions is known as adaptive radiation. This is possible due to natural selection. One of the most common examples of adaptive radiation is that of Darwin's finches which he found on Galapagos islands. He observed a variety of birds on the island, all of which were formed from a single seed-eating species which landed there accidentally. Thus due to the different feeding habits, birds with a variety of beaks developed. Different birds with a difference in the availability of food developed different eating habits which helped them all to survive in that environment.

Examinations • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • What is adaptive radiation? Adaptive radiation is the evolutionary diversification of many related species from a common ancestral species in a relatively short period. Osborne (1902) coined the term “Adaptive Radiation”. He stated that each large and isolated region, with sufficiently varied topography, soil, vegetation, climate, will lead to organisms with diverse characteristics. Darwin had called it “Divergence”, i.e. the tendency in an organism descended from the same ancestor to diverge in character as they undergo changes. Adaptive radiation plays a significant role in macroevolution. Adaptive radiation gives rise to species diversity in a geographical area. Adaptive Radiation Causes: Adaptive radiation is more common during major environmental changes and physical disturbances. It also helps an organism to successfully spread into other environments. Furthermore, it leads to speciation. Moreover, it also leads to phenotypically dissimilar, but related species. Major causes of adaptive radiation are: • Ecological opportunities: When an organism enters a new area with lots of ecological opportunities, species diversify to exploit these resource...

Chapter 7 Evolution The CBSE Class 12 Biology chapter 7 covers the concepts related to Evolution. Like all the other chapters in the NCERT textbooks, chapter 7 is followed by an exercise for students to solve. Students preparing for other competitive exams and Board exams can refer to Vidyakul’s NCERT notes for chapter 7 Biology to prepare and analyze their preparations accordingly. These practice questions make it easier for students to comprehend the concept. Moreover, Vidyakul’s subject experts have offered explanations for over 50 concepts such as the evolution of life forms, the evolution of man, biological evolution, etc. CBSE CLASS 12th BIOLOGY CH-7 Points to Remember Students can go through the following points to score well and achieve excellent results in the Class 12 Biology exam: • Evolution is often referred to as the study of the origin and development of life forms on earth. • Evolution answers questions like how did humans appear on earth and how different kinds of organisms exist in different habitats. • The first organisms could be single-cell organisms that lived in a water medium. These single-cell organisms eventually evolved into larger organisms over millions of years. • The expansion of the observable universe, according to the Big Bang theory, began with a large-scale and violent explosion of a small, primordial “super-atom.” • Homologous organs are found in forms that show adaptive radiation from a common ancestor, indicating ‘divergent evolution....

Adaptive radiation: • Adaptive radiation is a rapid increase in the number of species having a common ancestor. • It is characterized by great morphological and ecological diversity. • The main reason behind adaptive radiation is the adaptation of organisms to new ecological niches. Example of adaptive radiation: • An example of adaptive radiation is Darwin's finches or the Galapagos finches. • It was found that during evolution, the morphology and size of the beaks of Darwin's finches changed. • Due to changes in their beak size their food habits also changed, few ate small animals or insects while others fed on plants.

The Van Allen radiation belts are symmetric about the Earth's magnetic axis, which is tilted with respect to the Earth's rotational axis by an angle of approximately 11°. The intersection between the magnetic and rotation axes of the Earth is located not at the Earth's center, but some 450 to 500km (280 to 310mi) away. Because of this asymmetry, the inner Van Allen belt is closest to the Earth's surface over the south Atlantic Ocean where it dips down to 200km (120mi) in altitude, and farthest from the Earth's surface over the north Pacific Ocean. Area of the South Atlantic Anomaly, 1840 to 2020. If Earth's magnetism is represented by a bar magnet of small size but strong intensity (" The shape of the SAA changes over time. Since its initial discovery in 1958, −50° to 0° geographic latitude and from −90° to +40° longitude. Current literature suggests that a slow weakening of the The South Atlantic Anomaly seems to be caused by a huge reservoir of very dense rock inside the Earth called the Intensity and effects [ ] • ^ a b Pavón-Carrasco, F. Javier; De Santis, Angelo (April 2016). Frontiers in Earth Science. 4. 40. • Rao, G. S. (2010). Global Navigation Satellite Systems: With Essentials of Satellite Communications. New Delhi: Tata McGraw-Hill. p.125. 978-0-07-070029-1. • Stassinopoulos, Epaminondas G.; Xapsos, Michael A.; Stauffer, Craig A. (December 2015). • Crotts, Arlin (2014). The New Moon: Water, Exploration, and Future Habitation. 978-0-521-76224-3. • ". NASA . Retr...

About This Quiz & Worksheet This quiz and printable worksheet will test your ability to understand about the evolutionary process of adaptive radiation. You will be quizzed on terms related to and examples of this process. Quiz and Worksheet Goals In these assessments, you'll be tested on: • The term used to describe an organism's habitat • Identifying an example of adaptive radiation • The time it takes for adaptive radiation to happen Skills Practiced This worksheet and quiz will allow you to test the following skills: • Reading comprehension - ensure that you draw the most important information about what adaptive radiation is • Critical thinking - apply relevant concepts to examine information about the evolving of species in a different light • Information recall - access the knowledge you've gained regarding competition among organisms in nature Additional Learning To learn more about this topic, review the accompanying lesson called Adaptive Radiation: Definition, Examples & Quiz. This lesson covers the following objectives: • Define adaptive radiation • Provide an example of how adaptive radiation works • Discuss selective pressures • Illustrate how competition occurs between animals in nature • Innate Behavior: Reflexes, Kineses and Taxis Quiz • Learned Behavior: Imprinting, Habituation and Conditioning Quiz • Social Behavior: The Cost-Benefit of Altruism and Kin Selection Quiz • Social Behavior: Agonistic, Dominance Hierarchies, & Territoriality Quiz • Social Sys...

Reason Ancestral seed-eating stock of Darwin's finches radiated out from South America mainland to different geographical areas of the Galapagos Islands, where they found competitor-free new habitats. Darwin's finches show a variety of beaks suited for eating large seeds, flying insects and cactus seeds.