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Invasions of exotic species into new geographical areas sometimes occur naturally without human agency. However, human actions have increased this trickle to a flood. Human caused introductions may occur either accidently or as a consequence of human transport, or intentionally but illegally to serve some private purpose or legitimately to procure some hoped-for public benefit by bringing a pest under control, producing new agricultural products or providing novel recreational opportunities. Many introduced species are assimilated into communities without much obvious effect. However some have been responsible for dramatic changes to native species and native communities. For example, the accidental introduction of the brown tree snake, Boiga irregularis into Guam, an island in the pacific, has through nest predation reduced 10 endemic forest bird species to the point of extinction.
One of the major reasons for the world’s great biodiversity is the occurrence of centres of endemism so that similar habitats in different parts of the world are occupied by different groups of species that happen it have evolved there. If the species naturally had access to everywhere on the globe, we might expect a relatively small number of successful species to become dominant in each biome. The extent to which this homogenisation can happen naturally is restricted by the limited powers of dispersal of most species in the face of the physical barriers that exist to dispersal. By virtue of the transport opportunities offered by humans, these barriers have been breached by an ever-increasing number of exotic species. 
The effects of introductions have been to convert a hugely diverse range of local community compositions into something much more homogenous.
It would be wrong, however, to conclude that introducing species to a region will inevitably cause a decline in species richness there. For example, there are numerous species of plants, invertebrates and vertebrates found in continental Europe but absent from the British Isles (many because they have so far failed to recolonize after the last glaciations).Their introduction would be likely to augment British biodiversity. The significant detrimental effect noted above arises where aggressive species provide a novel challenge to endemic biotas ill-equipped to deal with them.
 
 
Q. How is homogenization prevented under natural conditions?
  • a)
    Evolution of groups of species specific to local habitats.
  • b)
    Presence of oceans and mountain ranges
  • c)
    Strong adaptation of groups of specific to local physical and climatic conditionsd
  • d)
    All the statements (a), (b) and (c) given above are correct in this context.
Correct answer is option 'B'. Can you explain this answer?
Verified Answer
PassageIInvasions of exotic species into new geographical areas someti...
Solution: b)Homogenization and endemism are different things as per the passage. Options (a) and (c) show the reasons for endemism. Only option (b) shows the reasons for the prevention of homogenization.
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PassageIInvasions of exotic species into new geographical areas sometimes occur naturally without human agency. However, human actions have increased this trickle to a flood. Human caused introductions may occur either accidently or as a consequence of human transport, or intentionally but illegally to serve some private purpose or legitimately to procure some hoped-for public benefit by bringing a pest under control, producing new agricultural products or providing novel recreational opportunities. Many introduced species are assimilated into communities without much obvious effect. However some have been responsible for dramatic changes to native species and native communities. For example, the accidental introduction of the brown tree snake, Boiga irregularis into Guam, an island in the pacific, has through nest predation reduced 10 endemic forest bird species to the point of extinction.One of the major reasons for the worlds great biodiversity is the occurrence of centres of endemism so that similar habitats in different parts of the world are occupied by different groups of species that happen it have evolved there. If the species naturally had access to everywhere on the globe, we might expect a relatively small number of successful species to become dominant in each biome. The extent to which this homogenisation can happen naturally is restricted by the limited powers of dispersal of most species in the face of the physical barriers that exist to dispersal. By virtue of the transport opportunities offered by humans, these barriers have been breached by an ever-increasing number of exotic species.The effects of introductions have been to convert a hugely diverse range of local community compositions into something much more homogenous.It would be wrong, however, to conclude that introducing species to a region will inevitably cause a decline in species richness there. For example, there are numerous species of plants, invertebrates and vertebrates found in continental Europe but absent from the British Isles (many because they have so far failed to recolonize after the last glaciations).Their introduction would be likely to augment British biodiversity. The significant detrimental effect noted above arises where aggressive species provide a novel challenge to endemic biotas ill-equipped to deal with them.Q. How have the human beings influenced the biodiversity?1. By smuggling live organism2. By building highways3. By making ecosystems sensitive so that new species are not allowed4. By ensuring that new species do not have major impact on local species.Which of the statements given above are correct?

Directions for the following 11 questions:Read the following three passages and solve the items that follow each passage. Your Solutions to these passages should be based on these passages only.PassageIInvasions of exotic species into new geographical areas sometimes occur naturally without human agency. However, human actions have increased this trickle to a flood. Human caused introductions may occur either accidently or as a consequence of human transport, or intentionally but illegally to serve some private purpose or legitimately to procure some hoped-for public benefit by bringing a pest under control, producing new agricultural products or providing novel recreational opportunities. Many introduced species are assimilated into communities without much obvious effect. However some have been responsible for dramatic changes to native species and native communities. For example, the accidental introduction of the brown tree snake, Boiga irregularis into Guam, an island in the pacific, has through nest predation reduced 10 endemic forest bird species to the point of extinction.One of the major reasons for the worlds great biodiversity is the occurrence of centres of endemism so that similar habitats in different parts of the world are occupied by different groups of species that happen it have evolved there. If the species naturally had access to everywhere on the globe, we might expect a relatively small number of successful species to become dominant in each biome. The extent to which this homogenisation can happen naturally is restricted by the limited powers of dispersal of most species in the face of the physical barriers that exist to dispersal. By virtue of the transport opportunities offered by humans, these barriers have been breached by an ever-increasing number of exotic species.The effects of introductions have been to convert a hugely diverse range of local community compositions into something much more homogenous.It would be wrong, however, to conclude that introducing species to a region will inevitably cause a decline in species richness there. For example, there are numerous species of plants, invertebrates and vertebrates found in continental Europe but absent from the British Isles (many because they have so far failed to recolonize after the last glaciations).Their introduction would be likely to augment British biodiversity. The significant detrimental effect noted above arises where aggressive species provide a novel challenge to endemic biotas ill-equipped to deal with them.Q. With reference to the passage, which of the following statements is correct?

PassageIInvasions of exotic species into new geographical areas sometimes occur naturally without human agency. However, human actions have increased this trickle to a flood. Human caused introductions may occur either accidently or as a consequence of human transport, or intentionally but illegally to serve some private purpose or legitimately to procure some hoped-for public benefit by bringing a pest under control, producing new agricultural products or providing novel recreational opportunities. Many introduced species are assimilated into communities without much obvious effect. However some have been responsible for dramatic changes to native species and native communities. For example, the accidental introduction of the brown tree snake, Boiga irregularis into Guam, an island in the pacific, has through nest predation reduced 10 endemic forest bird species to the point of extinction.One of the major reasons for the worlds great biodiversity is the occurrence of centres of endemism so that similar habitats in different parts of the world are occupied by different groups of species that happen it have evolved there. If the species naturally had access to everywhere on the globe, we might expect a relatively small number of successful species to become dominant in each biome. The extent to which this homogenisation can happen naturally is restricted by the limited powers of dispersal of most species in the face of the physical barriers that exist to dispersal. By virtue of the transport opportunities offered by humans, these barriers have been breached by an ever-increasing number of exotic species.The effects of introductions have been to convert a hugely diverse range of local community compositions into something much more homogenous.It would be wrong, however, to conclude that introducing species to a region will inevitably cause a decline in species richness there. For example, there are numerous species of plants, invertebrates and vertebrates found in continental Europe but absent from the British Isles (many because they have so far failed to recolonize after the last glaciations).Their introduction would be likely to augment British biodiversity. The significant detrimental effect noted above arises where aggressive species provide a novel challenge to endemic biotas ill-equipped to deal with them.Q. Why does man introduce exotic species into new geographical areas?1. To bread exotic species with local varieties.2. To increase agricultural productivity.3. for beautification and landscaping.Which of the above statements is/are correct?

PassageIInvasions of exotic species into new geographical areas sometimes occur naturally without human agency. However, human actions have increased this trickle to a flood. Human caused introductions may occur either accidently or as a consequence of human transport, or intentionally but illegally to serve some private purpose or legitimately to procure some hoped-for public benefit by bringing a pest under control, producing new agricultural products or providing novel recreational opportunities. Many introduced species are assimilated into communities without much obvious effect. However some have been responsible for dramatic changes to native species and native communities. For example, the accidental introduction of the brown tree snake, Boiga irregularis into Guam, an island in the pacific, has through nest predation reduced 10 endemic forest bird species to the point of extinction.One of the major reasons for the worlds great biodiversity is the occurrence of centres of endemism so that similar habitats in different parts of the world are occupied by different groups of species that happen it have evolved there. If the species naturally had access to everywhere on the globe, we might expect a relatively small number of successful species to become dominant in each biome. The extent to which this homogenisation can happen naturally is restricted by the limited powers of dispersal of most species in the face of the physical barriers that exist to dispersal. By virtue of the transport opportunities offered by humans, these barriers have been breached by an ever-increasing number of exotic species.The effects of introductions have been to convert a hugely diverse range of local community compositions into something much more homogenous.It would be wrong, however, to conclude that introducing species to a region will inevitably cause a decline in species richness there. For example, there are numerous species of plants, invertebrates and vertebrates found in continental Europe but absent from the British Isles (many because they have so far failed to recolonize after the last glaciations).Their introduction would be likely to augment British biodiversity. The significant detrimental effect noted above arises where aggressive species provide a novel challenge to endemic biotas ill-equipped to deal with them.Q. What can be the impact of invasion of exotic species on an ecosystem?1. Erosion of endemic species.2. Change in the species composition of the community of the ecosystem. Select the correct Solution: using the codes given below

Invasions of exotic species into new geographic areas sometimes occur naturally and without human agency. However, human actions have increased this trickle to a flood. Human-caused introductions may occur either accidentally as a consequence of human transport, or intentionally but illegally to serve some private purpose or legitimately to procure some hoped-for public benefit by bringing a pest under control, producing new agricultural products new agricultural products or providing novel recreational opportunities. Many introduced species are assimilated into communities without much obvious effect. However, some have been responsible for dramatic changes to native species and natural communities. For example, the accidental introduction of the brown tree snake Boiga irregularis into Guam, an island in the Pacific, has through nest predation reduced 10 endemic forest bird species to the point of extinction.One of the major reasons for the worlds great biodiversity is the occurrence of centers of endemism so that similar habitats in different parts of the world are occupied by different groups of species that happen to have evolved there. If every species naturally had access to everywhere on the globe, we might expect a relatively small number of successful species to become dominant in each biome. The extent to which this homogenization can happen naturally is restricted by the limited powers of dispersal. By virtue of the transport opportunities offered by humans, these barriers have been breached by an ever-increasing number of exotic species. The effects of introductions have been to convert a hugely diverse range of local community compositions into something much more homogeneous.It would be wrong, however, to conclude that introducing species to a region will inevitably cause a decline in species richness there. For example, there are numerous species of plants, invertebrates and vertebrates found in continental Europe but absent from the British Isles (many because they have so far failed to recolonize after the last glaciations). Their introduction would be likely to significant detrimental effect noted above arises where aggressive species provide a novel challenge to endemic biotas ill- equipped to deal with them.Q.Why does man introduce exotic species into new geographical areas?1) To breed exotic species with local varieties.2) To increase agricultural productivity.3) For beautification and landscaping.Which of the above statements is/are correct?

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PassageIInvasions of exotic species into new geographical areas sometimes occur naturally without human agency. However, human actions have increased this trickle to a flood. Human caused introductions may occur either accidently or as a consequence of human transport, or intentionally but illegally to serve some private purpose or legitimately to procure some hoped-for public benefit by bringing a pest under control, producing new agricultural products or providing novel recreational opportunities. Many introduced species are assimilated into communities without much obvious effect. However some have been responsible for dramatic changes to native species and native communities. For example, the accidental introduction of the brown tree snake, Boiga irregularis into Guam, an island in the pacific, has through nest predation reduced 10 endemic forest bird species to the point of extinction.One of the major reasons for the world’s great biodiversity is the occurrence of centres of endemism so that similar habitats in different parts of the world are occupied by different groups of species that happen it have evolved there. If the species naturally had access to everywhere on the globe, we might expect a relatively small number of successful species to become dominant in each biome. The extent to which this homogenisation can happen naturally is restricted by the limited powers of dispersal of most species in the face of the physical barriers that exist to dispersal. By virtue of the transport opportunities offered by humans, these barriers have been breached by an ever-increasing number of exotic species.The effects of introductions have been to convert a hugely diverse range of local community compositions into something much more homogenous.It would be wrong, however, to conclude that introducing species to a region will inevitably cause a decline in species richness there. For example, there are numerous species of plants, invertebrates and vertebrates found in continental Europe but absent from the British Isles (many because they have so far failed to recolonize after the last glaciations).Their introduction would be likely to augment British biodiversity. The significant detrimental effect noted above arises where aggressive species provide a novel challenge to endemic biotas ill-equipped to deal with them.Q. How is homogenization prevented under natural conditions?a)Evolution of groups of species specific to local habitats.b)Presence of oceans and mountain rangesc)Strong adaptation of groups of specific to local physical and climatic conditionsdd)All the statements (a), (b) and (c) given above are correct in this context.Correct answer is option 'B'. Can you explain this answer?
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PassageIInvasions of exotic species into new geographical areas sometimes occur naturally without human agency. However, human actions have increased this trickle to a flood. Human caused introductions may occur either accidently or as a consequence of human transport, or intentionally but illegally to serve some private purpose or legitimately to procure some hoped-for public benefit by bringing a pest under control, producing new agricultural products or providing novel recreational opportunities. Many introduced species are assimilated into communities without much obvious effect. However some have been responsible for dramatic changes to native species and native communities. For example, the accidental introduction of the brown tree snake, Boiga irregularis into Guam, an island in the pacific, has through nest predation reduced 10 endemic forest bird species to the point of extinction.One of the major reasons for the world’s great biodiversity is the occurrence of centres of endemism so that similar habitats in different parts of the world are occupied by different groups of species that happen it have evolved there. If the species naturally had access to everywhere on the globe, we might expect a relatively small number of successful species to become dominant in each biome. The extent to which this homogenisation can happen naturally is restricted by the limited powers of dispersal of most species in the face of the physical barriers that exist to dispersal. By virtue of the transport opportunities offered by humans, these barriers have been breached by an ever-increasing number of exotic species.The effects of introductions have been to convert a hugely diverse range of local community compositions into something much more homogenous.It would be wrong, however, to conclude that introducing species to a region will inevitably cause a decline in species richness there. For example, there are numerous species of plants, invertebrates and vertebrates found in continental Europe but absent from the British Isles (many because they have so far failed to recolonize after the last glaciations).Their introduction would be likely to augment British biodiversity. The significant detrimental effect noted above arises where aggressive species provide a novel challenge to endemic biotas ill-equipped to deal with them.Q. How is homogenization prevented under natural conditions?a)Evolution of groups of species specific to local habitats.b)Presence of oceans and mountain rangesc)Strong adaptation of groups of specific to local physical and climatic conditionsdd)All the statements (a), (b) and (c) given above are correct in this context.Correct answer is option 'B'. Can you explain this answer? for UPSC 2024 is part of UPSC preparation. The Question and answers have been prepared according to the UPSC exam syllabus. Information about PassageIInvasions of exotic species into new geographical areas sometimes occur naturally without human agency. However, human actions have increased this trickle to a flood. Human caused introductions may occur either accidently or as a consequence of human transport, or intentionally but illegally to serve some private purpose or legitimately to procure some hoped-for public benefit by bringing a pest under control, producing new agricultural products or providing novel recreational opportunities. Many introduced species are assimilated into communities without much obvious effect. However some have been responsible for dramatic changes to native species and native communities. For example, the accidental introduction of the brown tree snake, Boiga irregularis into Guam, an island in the pacific, has through nest predation reduced 10 endemic forest bird species to the point of extinction.One of the major reasons for the world’s great biodiversity is the occurrence of centres of endemism so that similar habitats in different parts of the world are occupied by different groups of species that happen it have evolved there. If the species naturally had access to everywhere on the globe, we might expect a relatively small number of successful species to become dominant in each biome. The extent to which this homogenisation can happen naturally is restricted by the limited powers of dispersal of most species in the face of the physical barriers that exist to dispersal. By virtue of the transport opportunities offered by humans, these barriers have been breached by an ever-increasing number of exotic species.The effects of introductions have been to convert a hugely diverse range of local community compositions into something much more homogenous.It would be wrong, however, to conclude that introducing species to a region will inevitably cause a decline in species richness there. For example, there are numerous species of plants, invertebrates and vertebrates found in continental Europe but absent from the British Isles (many because they have so far failed to recolonize after the last glaciations).Their introduction would be likely to augment British biodiversity. The significant detrimental effect noted above arises where aggressive species provide a novel challenge to endemic biotas ill-equipped to deal with them.Q. How is homogenization prevented under natural conditions?a)Evolution of groups of species specific to local habitats.b)Presence of oceans and mountain rangesc)Strong adaptation of groups of specific to local physical and climatic conditionsdd)All the statements (a), (b) and (c) given above are correct in this context.Correct answer is option 'B'. Can you explain this answer? covers all topics & solutions for UPSC 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for PassageIInvasions of exotic species into new geographical areas sometimes occur naturally without human agency. However, human actions have increased this trickle to a flood. Human caused introductions may occur either accidently or as a consequence of human transport, or intentionally but illegally to serve some private purpose or legitimately to procure some hoped-for public benefit by bringing a pest under control, producing new agricultural products or providing novel recreational opportunities. Many introduced species are assimilated into communities without much obvious effect. However some have been responsible for dramatic changes to native species and native communities. For example, the accidental introduction of the brown tree snake, Boiga irregularis into Guam, an island in the pacific, has through nest predation reduced 10 endemic forest bird species to the point of extinction.One of the major reasons for the world’s great biodiversity is the occurrence of centres of endemism so that similar habitats in different parts of the world are occupied by different groups of species that happen it have evolved there. If the species naturally had access to everywhere on the globe, we might expect a relatively small number of successful species to become dominant in each biome. The extent to which this homogenisation can happen naturally is restricted by the limited powers of dispersal of most species in the face of the physical barriers that exist to dispersal. By virtue of the transport opportunities offered by humans, these barriers have been breached by an ever-increasing number of exotic species.The effects of introductions have been to convert a hugely diverse range of local community compositions into something much more homogenous.It would be wrong, however, to conclude that introducing species to a region will inevitably cause a decline in species richness there. For example, there are numerous species of plants, invertebrates and vertebrates found in continental Europe but absent from the British Isles (many because they have so far failed to recolonize after the last glaciations).Their introduction would be likely to augment British biodiversity. The significant detrimental effect noted above arises where aggressive species provide a novel challenge to endemic biotas ill-equipped to deal with them.Q. How is homogenization prevented under natural conditions?a)Evolution of groups of species specific to local habitats.b)Presence of oceans and mountain rangesc)Strong adaptation of groups of specific to local physical and climatic conditionsdd)All the statements (a), (b) and (c) given above are correct in this context.Correct answer is option 'B'. Can you explain this answer?.
Solutions for PassageIInvasions of exotic species into new geographical areas sometimes occur naturally without human agency. However, human actions have increased this trickle to a flood. Human caused introductions may occur either accidently or as a consequence of human transport, or intentionally but illegally to serve some private purpose or legitimately to procure some hoped-for public benefit by bringing a pest under control, producing new agricultural products or providing novel recreational opportunities. Many introduced species are assimilated into communities without much obvious effect. However some have been responsible for dramatic changes to native species and native communities. For example, the accidental introduction of the brown tree snake, Boiga irregularis into Guam, an island in the pacific, has through nest predation reduced 10 endemic forest bird species to the point of extinction.One of the major reasons for the world’s great biodiversity is the occurrence of centres of endemism so that similar habitats in different parts of the world are occupied by different groups of species that happen it have evolved there. If the species naturally had access to everywhere on the globe, we might expect a relatively small number of successful species to become dominant in each biome. The extent to which this homogenisation can happen naturally is restricted by the limited powers of dispersal of most species in the face of the physical barriers that exist to dispersal. By virtue of the transport opportunities offered by humans, these barriers have been breached by an ever-increasing number of exotic species.The effects of introductions have been to convert a hugely diverse range of local community compositions into something much more homogenous.It would be wrong, however, to conclude that introducing species to a region will inevitably cause a decline in species richness there. For example, there are numerous species of plants, invertebrates and vertebrates found in continental Europe but absent from the British Isles (many because they have so far failed to recolonize after the last glaciations).Their introduction would be likely to augment British biodiversity. The significant detrimental effect noted above arises where aggressive species provide a novel challenge to endemic biotas ill-equipped to deal with them.Q. How is homogenization prevented under natural conditions?a)Evolution of groups of species specific to local habitats.b)Presence of oceans and mountain rangesc)Strong adaptation of groups of specific to local physical and climatic conditionsdd)All the statements (a), (b) and (c) given above are correct in this context.Correct answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for UPSC. Download more important topics, notes, lectures and mock test series for UPSC Exam by signing up for free.
Here you can find the meaning of PassageIInvasions of exotic species into new geographical areas sometimes occur naturally without human agency. However, human actions have increased this trickle to a flood. Human caused introductions may occur either accidently or as a consequence of human transport, or intentionally but illegally to serve some private purpose or legitimately to procure some hoped-for public benefit by bringing a pest under control, producing new agricultural products or providing novel recreational opportunities. Many introduced species are assimilated into communities without much obvious effect. However some have been responsible for dramatic changes to native species and native communities. For example, the accidental introduction of the brown tree snake, Boiga irregularis into Guam, an island in the pacific, has through nest predation reduced 10 endemic forest bird species to the point of extinction.One of the major reasons for the world’s great biodiversity is the occurrence of centres of endemism so that similar habitats in different parts of the world are occupied by different groups of species that happen it have evolved there. If the species naturally had access to everywhere on the globe, we might expect a relatively small number of successful species to become dominant in each biome. The extent to which this homogenisation can happen naturally is restricted by the limited powers of dispersal of most species in the face of the physical barriers that exist to dispersal. By virtue of the transport opportunities offered by humans, these barriers have been breached by an ever-increasing number of exotic species.The effects of introductions have been to convert a hugely diverse range of local community compositions into something much more homogenous.It would be wrong, however, to conclude that introducing species to a region will inevitably cause a decline in species richness there. For example, there are numerous species of plants, invertebrates and vertebrates found in continental Europe but absent from the British Isles (many because they have so far failed to recolonize after the last glaciations).Their introduction would be likely to augment British biodiversity. The significant detrimental effect noted above arises where aggressive species provide a novel challenge to endemic biotas ill-equipped to deal with them.Q. How is homogenization prevented under natural conditions?a)Evolution of groups of species specific to local habitats.b)Presence of oceans and mountain rangesc)Strong adaptation of groups of specific to local physical and climatic conditionsdd)All the statements (a), (b) and (c) given above are correct in this context.Correct answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of PassageIInvasions of exotic species into new geographical areas sometimes occur naturally without human agency. However, human actions have increased this trickle to a flood. Human caused introductions may occur either accidently or as a consequence of human transport, or intentionally but illegally to serve some private purpose or legitimately to procure some hoped-for public benefit by bringing a pest under control, producing new agricultural products or providing novel recreational opportunities. Many introduced species are assimilated into communities without much obvious effect. However some have been responsible for dramatic changes to native species and native communities. For example, the accidental introduction of the brown tree snake, Boiga irregularis into Guam, an island in the pacific, has through nest predation reduced 10 endemic forest bird species to the point of extinction.One of the major reasons for the world’s great biodiversity is the occurrence of centres of endemism so that similar habitats in different parts of the world are occupied by different groups of species that happen it have evolved there. If the species naturally had access to everywhere on the globe, we might expect a relatively small number of successful species to become dominant in each biome. The extent to which this homogenisation can happen naturally is restricted by the limited powers of dispersal of most species in the face of the physical barriers that exist to dispersal. By virtue of the transport opportunities offered by humans, these barriers have been breached by an ever-increasing number of exotic species.The effects of introductions have been to convert a hugely diverse range of local community compositions into something much more homogenous.It would be wrong, however, to conclude that introducing species to a region will inevitably cause a decline in species richness there. For example, there are numerous species of plants, invertebrates and vertebrates found in continental Europe but absent from the British Isles (many because they have so far failed to recolonize after the last glaciations).Their introduction would be likely to augment British biodiversity. The significant detrimental effect noted above arises where aggressive species provide a novel challenge to endemic biotas ill-equipped to deal with them.Q. How is homogenization prevented under natural conditions?a)Evolution of groups of species specific to local habitats.b)Presence of oceans and mountain rangesc)Strong adaptation of groups of specific to local physical and climatic conditionsdd)All the statements (a), (b) and (c) given above are correct in this context.Correct answer is option 'B'. Can you explain this answer?, a detailed solution for PassageIInvasions of exotic species into new geographical areas sometimes occur naturally without human agency. However, human actions have increased this trickle to a flood. Human caused introductions may occur either accidently or as a consequence of human transport, or intentionally but illegally to serve some private purpose or legitimately to procure some hoped-for public benefit by bringing a pest under control, producing new agricultural products or providing novel recreational opportunities. Many introduced species are assimilated into communities without much obvious effect. However some have been responsible for dramatic changes to native species and native communities. For example, the accidental introduction of the brown tree snake, Boiga irregularis into Guam, an island in the pacific, has through nest predation reduced 10 endemic forest bird species to the point of extinction.One of the major reasons for the world’s great biodiversity is the occurrence of centres of endemism so that similar habitats in different parts of the world are occupied by different groups of species that happen it have evolved there. If the species naturally had access to everywhere on the globe, we might expect a relatively small number of successful species to become dominant in each biome. The extent to which this homogenisation can happen naturally is restricted by the limited powers of dispersal of most species in the face of the physical barriers that exist to dispersal. By virtue of the transport opportunities offered by humans, these barriers have been breached by an ever-increasing number of exotic species.The effects of introductions have been to convert a hugely diverse range of local community compositions into something much more homogenous.It would be wrong, however, to conclude that introducing species to a region will inevitably cause a decline in species richness there. For example, there are numerous species of plants, invertebrates and vertebrates found in continental Europe but absent from the British Isles (many because they have so far failed to recolonize after the last glaciations).Their introduction would be likely to augment British biodiversity. The significant detrimental effect noted above arises where aggressive species provide a novel challenge to endemic biotas ill-equipped to deal with them.Q. How is homogenization prevented under natural conditions?a)Evolution of groups of species specific to local habitats.b)Presence of oceans and mountain rangesc)Strong adaptation of groups of specific to local physical and climatic conditionsdd)All the statements (a), (b) and (c) given above are correct in this context.Correct answer is option 'B'. Can you explain this answer? has been provided alongside types of PassageIInvasions of exotic species into new geographical areas sometimes occur naturally without human agency. However, human actions have increased this trickle to a flood. Human caused introductions may occur either accidently or as a consequence of human transport, or intentionally but illegally to serve some private purpose or legitimately to procure some hoped-for public benefit by bringing a pest under control, producing new agricultural products or providing novel recreational opportunities. Many introduced species are assimilated into communities without much obvious effect. However some have been responsible for dramatic changes to native species and native communities. For example, the accidental introduction of the brown tree snake, Boiga irregularis into Guam, an island in the pacific, has through nest predation reduced 10 endemic forest bird species to the point of extinction.One of the major reasons for the world’s great biodiversity is the occurrence of centres of endemism so that similar habitats in different parts of the world are occupied by different groups of species that happen it have evolved there. If the species naturally had access to everywhere on the globe, we might expect a relatively small number of successful species to become dominant in each biome. The extent to which this homogenisation can happen naturally is restricted by the limited powers of dispersal of most species in the face of the physical barriers that exist to dispersal. By virtue of the transport opportunities offered by humans, these barriers have been breached by an ever-increasing number of exotic species.The effects of introductions have been to convert a hugely diverse range of local community compositions into something much more homogenous.It would be wrong, however, to conclude that introducing species to a region will inevitably cause a decline in species richness there. For example, there are numerous species of plants, invertebrates and vertebrates found in continental Europe but absent from the British Isles (many because they have so far failed to recolonize after the last glaciations).Their introduction would be likely to augment British biodiversity. The significant detrimental effect noted above arises where aggressive species provide a novel challenge to endemic biotas ill-equipped to deal with them.Q. How is homogenization prevented under natural conditions?a)Evolution of groups of species specific to local habitats.b)Presence of oceans and mountain rangesc)Strong adaptation of groups of specific to local physical and climatic conditionsdd)All the statements (a), (b) and (c) given above are correct in this context.Correct answer is option 'B'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice PassageIInvasions of exotic species into new geographical areas sometimes occur naturally without human agency. However, human actions have increased this trickle to a flood. Human caused introductions may occur either accidently or as a consequence of human transport, or intentionally but illegally to serve some private purpose or legitimately to procure some hoped-for public benefit by bringing a pest under control, producing new agricultural products or providing novel recreational opportunities. Many introduced species are assimilated into communities without much obvious effect. However some have been responsible for dramatic changes to native species and native communities. For example, the accidental introduction of the brown tree snake, Boiga irregularis into Guam, an island in the pacific, has through nest predation reduced 10 endemic forest bird species to the point of extinction.One of the major reasons for the world’s great biodiversity is the occurrence of centres of endemism so that similar habitats in different parts of the world are occupied by different groups of species that happen it have evolved there. If the species naturally had access to everywhere on the globe, we might expect a relatively small number of successful species to become dominant in each biome. The extent to which this homogenisation can happen naturally is restricted by the limited powers of dispersal of most species in the face of the physical barriers that exist to dispersal. By virtue of the transport opportunities offered by humans, these barriers have been breached by an ever-increasing number of exotic species.The effects of introductions have been to convert a hugely diverse range of local community compositions into something much more homogenous.It would be wrong, however, to conclude that introducing species to a region will inevitably cause a decline in species richness there. For example, there are numerous species of plants, invertebrates and vertebrates found in continental Europe but absent from the British Isles (many because they have so far failed to recolonize after the last glaciations).Their introduction would be likely to augment British biodiversity. The significant detrimental effect noted above arises where aggressive species provide a novel challenge to endemic biotas ill-equipped to deal with them.Q. How is homogenization prevented under natural conditions?a)Evolution of groups of species specific to local habitats.b)Presence of oceans and mountain rangesc)Strong adaptation of groups of specific to local physical and climatic conditionsdd)All the statements (a), (b) and (c) given above are correct in this context.Correct answer is option 'B'. Can you explain this answer? tests, examples and also practice UPSC tests.
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