Adaptive Radiation Questions in English

(D) When more than one adaptive radiation appeared to have occurred in an isolated geographical area (representing different habitats),one can call this convergent evolution.
In Australia,marsupials and placental mammals show many similar characteristics due to evolution in similar environmental conditions,despite being phylogenetically distinct.
This phenomenon,where unrelated species evolve similar traits as an adaptation to similar environments,is known as convergent evolution.

(C) Adaptive radiation is the process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography (habitats).
This phenomenon occurs when a population enters a new environment that offers multiple ecological niches (vacant habitats) with minimal competition.
As the population spreads into these diverse vacant habitats,they undergo natural selection and adapt to the specific conditions of each niche,eventually leading to the formation of new species.
Therefore,an area with many types of vacant habitats is the ideal condition for adaptive radiation to occur.

(N/A) Adaptive radiation is an evolutionary process that produces new species from a single,rapidly diversifying lineage. This process occurs due to natural selection.
An example of adaptive radiation is Darwin's finches,found on the Galapagos Islands.
$A$ large variety of finches is present on the Galapagos Islands that arose from a single species,which reached this land accidentally.
As a result,many new species have evolved,diverged,and adapted to occupy new habitats.
These finches have developed different eating habits and different types of beaks to suit their feeding habits.
The insectivorous,blood-sucking,and other species of finches with varied dietary habits have evolved from a single seed-eating finch ancestor.

(B) No,human evolution cannot be called adaptive radiation.
Adaptive radiation is an evolutionary process where organisms diversify rapidly from an ancestral species into a multitude of new forms,particularly when a change in the environment makes new resources available or creates new challenges.
Human evolution is a gradual process that occurred slowly over millions of years.
It represents an example of anagenesis,where a single lineage evolves into a new species without branching,rather than the rapid diversification seen in adaptive radiation.

(N/A) During his voyage,Darwin visited the Galapagos Islands. There,he observed an amazing diversity of creatures. He was particularly amazed by small black birds,which were later called Darwin's Finches.
He observed many varieties of finches on the same island. He realized that all the varieties had evolved on the island itself. From the original seed-eating features,many other forms with altered beaks evolved,enabling them to become insectivorous and vegetarian finches.
The process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography (habitats) is called adaptive radiation.
Types of Adaptive Radiation:
$1$. Divergent Evolution: This occurs when species from a common ancestor evolve into different forms to adapt to different environments (e.g.,Darwin's Finches,Australian Marsupials).
$2$. Convergent Evolution: This occurs when different species,not closely related,evolve similar traits as a result of having to adapt to similar environments or ecological niches (e.g.,Australian Marsupials and Placental Mammals).

(B) Adaptive radiation is the process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography (habitats).
Pre-existing variations within a population are the most important pre-condition for adaptive radiation.
These variations allow individuals to adapt to different ecological niches or habitats,leading to the divergence of species from a common ancestor.

(N/A) Divergent evolution is a process where related species evolve different traits to adapt to different environmental pressures or functional requirements.
$1$. Example: The forelimbs of whales,bats,cheetahs,and humans (all mammals) share a similar anatomical pattern of bones,including the humerus,radius,ulna,carpals,metacarpals,and phalanges.
$2$. Despite having the same ancestral structural plan,these forelimbs have evolved to perform different functions,such as swimming,flying,running,or grasping.
$3$. This phenomenon is known as homology,where structures are derived from a common ancestor but diverge in function.
$4$. The driving force behind divergent evolution is adaptive radiation,where organisms diversify from an ancestral species into a multitude of new forms to exploit different ecological niches.

(N/A) The phenomenon where organisms from different evolutionary lineages develop similar adaptive features due to living in similar habitats is known as $Convergent Evolution$.
In desert environments,plants like $Opuntia$ and $Cactus$ have evolved spines,which are modified leaves,to minimize water loss through transpiration.
Similarly,animals like camels and kangaroo rats exhibit adaptive strategies to conserve water in arid conditions.
They produce highly concentrated (hypertonic) urine and dry,solidified feces because most of the water is reabsorbed in the nephrons and the large intestine.
Another example is the evolution of Australian marsupials and placental mammals. Despite being distinct groups,they show $Adaptive Radiation$ leading to similar forms (e.g.,the placental mouse and the marsupial mouse) because they occupy similar ecological niches.

(N/A) During his voyage,$Charles \ Darwin$ visited the $Galapagos$ Islands.
He observed an amazing diversity of creatures there.
He was particularly amazed by small black birds,which were later called $Darwin's \ Finches$.
He observed many varieties of finches on the same island.
He conjectured that all the varieties had evolved on the island itself from an original seed-eating ancestor,a process known as $Adaptive \ Radiation$.

(N/A) Biogeographical evidence suggests that species restricted to widely separated regions show similarity of ancestry.
Habitat isolation had probably restricted these organisms to a particular geography on the Earth.
This can be explained with the help of the following process:
$\Rightarrow \quad$ Adaptive Radiation: The process of evolution of different species starting from a point in a geographical area and finally radiating to other areas of geography (habitats) is called adaptive radiation.
Examples of adaptive radiation include:
$(i)$ Darwin's Finches: Darwin observed an amazing diversity of creatures on the Galapagos Islands.
There,he saw small black birds that amazed him the most,later called Darwin's finches.
They represent one of the best examples of adaptive radiation.
He observed that there were many varieties of finches on the same island and all the varieties had evolved on the island itself from original seed-eating finches.
He explained that after originating from a common ancestral seed-eating stock,the finches must have radiated to different geographical areas and undergone adaptive changes,especially in the type of beaks.
Therefore,due to the gradual alterations in beaks,some became insectivorous and some vegetarian.
Living in isolation for a long time,new kinds of finches emerged that could function and survive in new habitats.

(N/A) Biogeographical evidence suggests that species restricted to widely separated regions often share a common ancestry. Habitat isolation likely restricted these organisms to specific geographical areas.
This can be explained through the following processes:
$1$. Adaptive Radiation: The process of evolution of different species starting from a single point in a geographical area and radiating to other geographical areas (habitats) is called adaptive radiation.
Examples of adaptive radiation:
$(i)$ Darwin's Finches: Darwin observed an amazing diversity of creatures on the Galapagos Islands. He saw small black birds that fascinated him,later known as Darwin's finches. They represent one of the best examples of adaptive radiation. He observed many varieties of finches on the same island,all of which evolved from original seed-eating finches. He explained that after originating from a common ancestral seed-eating stock,the finches radiated to different geographical areas and underwent adaptive changes,especially in their beak types. Due to these gradual alterations,some became insectivorous and others vegetarian. Living in isolation for a long time,new kinds of finches emerged that could function and survive in new habitats.
(ii) Marsupials of Australia: Another example is the Australian marsupials. $A$ number of marsupials,each different from the other,evolved from an ancestral stock,but all within the Australian island continent. When more than one adaptive radiation appears to have occurred in an isolated geographical area (representing different habitats),one can call this convergent evolution. Placental mammals in Australia also exhibit adaptive radiation in evolving into varieties of such placental mammals each of which appears to be similar to a corresponding marsupial (e.g.,placental wolf and Tasmanian wolf-marsupial).

(N/A) Biogeographical evidence suggests that species restricted to widely separated regions show similarity of ancestry.
Habitat isolation had probably restricted these organisms to a particular geography on the Earth.
This can be explained with the help of the following process:
$\Rightarrow$ Adaptive Radiation: The process of evolution of different species starting from a point in a geographical area and finally radiating to other areas of geography (habitats) is called adaptive radiation.
Examples of adaptive radiation include:
$(i)$ Darwin's Finches: Darwin observed an amazing diversity of creatures on the Galapagos Islands.
There,he saw small black birds that amazed him the most,later called Darwin's finches.
They represent one of the best examples of adaptive radiation.
He observed that there were many varieties of finches on the same island,and all the varieties had evolved on the island itself from original seed-eating finches.
He concluded that after originating from a common ancestral seed-eating stock,the finches must have radiated to different geographical areas and undergone adaptive changes,especially in the type of beaks.
Therefore,due to the gradual alterations in beaks,some became insectivorous and some vegetarian.
Living in isolation for a long time,new kinds of finches emerged that could function and survive in new habitats.

(N/A) Convergent evolution occurs when different groups of organisms evolve similar traits independently as they adapt to similar environments.
In Australia,many marsupials (pouched mammals) and placental mammals have evolved to fill similar ecological niches,resulting in a striking resemblance between them despite being phylogenetically distant.
For example,the Australian marsupial 'Tasmanian wolf' and the placental 'Wolf' show remarkable similarities in their body structure and predatory habits,even though they belong to different mammalian lineages.
This phenomenon,where more than one adaptive radiation appears to have occurred in an isolated geographical area (Australia),is known as convergent evolution.
Essentially,because these two groups were subjected to similar selective pressures in their respective environments,they evolved analogous structures to survive,demonstrating that similar environmental conditions can lead to the evolution of similar phenotypic traits in unrelated species.

(N/A) Biogeographical evidence suggests that species restricted to widely separated regions show similarity of ancestry.
Habitat isolation likely restricted these organisms to particular geographical areas on Earth.
This can be explained with the help of the following processes:
$\Rightarrow$ Adaptive Radiation: The process of evolution of different species starting from a point in a geographical area and finally radiating to other areas of geography (habitats) is called adaptive radiation.
Examples of adaptive radiation are:
$(i)$ Darwin's Finches: Darwin observed an amazing diversity of creatures on the Galapagos Islands.
There,he saw small black birds that amazed him the most,later called Darwin's finches.
They represent one of the best examples of adaptive radiation.
He observed that there were many varieties of finches on the same island,and all the varieties had evolved on the island itself from original seed-eating finches.
He explained that after originating from a common ancestral seed-eating stock,the finches must have radiated to different geographical areas and undergone adaptive changes,especially in the type of beaks.
Therefore,due to gradual alterations in beaks,some became insectivorous and some vegetarian.
Living in isolation for a long time,new kinds of finches emerged that could function and survive in new habitats.

(N/A) An example of more than one adaptive radiation occurring in an isolated geographic area is the evolution of Australian marsupials and placental mammals.
In this case,a number of Australian marsupials,each different from the other,evolved from an ancestral stock,but all within the Australian island continent. Placental mammals in other parts of the world also exhibit adaptive radiation.
When more than one adaptive radiation appears to have occurred in an isolated geographical area,and two or more groups of unrelated animals come to resemble each other due to a similar mode of life or habitat,it is called $Convergent$ $Evolution$.
It is named $Convergent$ $Evolution$ because different evolutionary lineages 'converge' or come together to develop similar adaptive features to survive in similar environmental conditions.

(N/A) Homology refers to the similarity between organs of different animals based on common ancestry or common embryonic origin. These organs are built on the same fundamental structural pattern but perform varied functions and have different appearances. For example,the flippers of a seal,and the forelimbs of birds,bats,horses,and humans look different and perform different functions,but they exhibit the same underlying structural plan.
Adaptive radiation (divergent evolution) represents the evolution of new forms in several directions starting from a common ancestral type. This process leads to the development of diverse species adapted to different environments from a single common ancestor.

(B) Charles Darwin,during his voyage on the $H$.$M$.$S$. Beagle,visited the Galapagos Islands. He observed that there were many varieties of finches in the same island. All the varieties,he conjectured,evolved on the island itself. From the original seed-eating features,many other forms with altered beaks arose,enabling them to become insectivorous and vegetarian finches. This process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography (habitats) is called adaptive radiation.

(C) The ancestral finches that migrated to the Galapagos Islands were originally seed-eating birds. Over time,due to adaptive radiation,they evolved into various forms with different beak shapes suited for different diets (such as insectivorous,cactus-eating,etc.). Therefore,the original or ancestral characteristic feature was seed-eating.

(A) Darwin's finches in the Galapagos Islands are a classic example of adaptive radiation.
These birds originated from a single ancestral species and diversified into different forms based on their feeding habits.
The primary structural adaptation that allowed them to exploit different food sources, such as insects, seeds, or fruits, was the modification of their $beak$ shape and size.
Therefore, the evolution of the beak enabled them to become insectivorous, vegetarian, or granivorous.

(A) The process of evolution of different species in a given geographical area starting from a point and radiating to other geographical areas is called $Adaptive \text{ } radiation$.
This phenomenon is best exemplified by $Darwin's \text{ } finches$ in the $Galapagos \text{ } Islands$ and $Australian \text{ } marsupials$.

(D) Darwin's finches are a classic example of $Adaptive \text{ } radiation$.
Adaptive radiation is an evolutionary process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches.
In the case of Darwin's finches on the Galapagos Islands, the original seed-eating finches from the mainland evolved into various species with different beak shapes adapted to different feeding habits (e.g., insect-eating, cactus-eating, seed-crushing) to exploit available niches.

(B) Marsupial radiation is a classic example of adaptive radiation.
When more than one adaptive radiation appeared to have occurred in an isolated geographical area (representing different habitats),one can call this convergent evolution.
Australia is the primary geographical region where marsupials evolved and diversified into various forms from an ancestral stock,filling different ecological niches.
Therefore,the correct option is $B$.

(D) The correct answer is $D$ (Bobcat).
Adaptive radiation is the process of evolution of different species in a given geographical area starting from a point and radiating to other areas of geography (habitats).
Australian marsupials like the Tiger cat,Koala,and Wombat are examples of adaptive radiation within the Australian continent.
However,the Bobcat is a placental mammal found in North America,not a marsupial,and therefore does not belong to the same group of Australian marsupial adaptive radiation.

(A) Adaptive radiation is the process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography (habitats).
Australian marsupials exhibit adaptive radiation,where a number of marsupials,each different from the other,evolved from an ancestral stock within the Australian island continent.
When more than one adaptive radiation appeared to have occurred in an isolated geographical area (representing different habitats),one can call this convergent evolution.
Placental mammals in Australia also exhibit adaptive radiation in evolving into varieties of such placental mammals each of which appears to be 'similar' to a corresponding marsupial (e.g.,Placental wolf and Tasmanian wolf-marsupial).
Lemur is a placental mammal (prosimian primate) and is not part of the Australian marsupial adaptive radiation series,whereas the others (Wolf,Banded anteater,Flying squirrel) have Australian marsupial counterparts (Tasmanian wolf,Numbat,Sugar glider) that are often compared in convergent evolution studies.

(D) Adaptive radiation is the process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography (habitats).
Darwin's finches in the Galapagos Islands are a classic example of adaptive radiation.
Similarly,Australian marsupials and placental mammals also exhibit adaptive radiation,where different species evolved from a common ancestor to adapt to different ecological niches.
Therefore,all the given options exhibit adaptive radiation.

(A) Convergent evolution occurs when different species evolve similar traits independently as a result of having to adapt to similar environments or ecological niches.
In the context of Australian marsupials,adaptive radiation led to the development of various marsupials that resemble placental mammals from other parts of the world.
The pair $Mole$ (a placental mammal) and $Numbat$ (a marsupial) is a classic example of convergent evolution,as both have evolved similar adaptations for burrowing and feeding on insects despite being phylogenetically distinct.

(A) Divergent evolution occurs when related species evolve different traits to adapt to different environments,often resulting in homologous structures.
Adaptive radiation is a type of divergent evolution where many species evolve from a single common ancestor in a specific geographical area.
In the given options,the 'Flying squirrel' (a placental mammal) and the 'Flying phalanger' (a marsupial mammal) are examples of convergent evolution,not divergent evolution,as they evolved similar traits independently in different lineages.
However,the question asks for a pair exhibiting divergent evolution. Among the choices,'Bobcat' and 'Wolf' are both placental mammals that share a common ancestor and have diverged into different ecological niches,representing divergent evolution.

(A) The Australian marsupials listed are:
$1$. Tasmanian tiger cat (Dasyurus maculatus)
$2$. Numbat (Myrmecobius fasciatus)
$3$. Tasmanian wolf (Thylacinus cynocephalus)
$4$. Flying phalanger (Petaurus breviceps)
$5$. Kangaroo (Macropodidae)
Wolf and Bobcat are placental mammals,not marsupials.
Therefore,there are $5$ Australian marsupials in the given list.

(B) To identify the placental mammals from the given list,we classify them based on their reproductive strategy:
$1$. Mole: Placental mammal.
$2$. Kangaroo: Marsupial (not placental).
$3$. Koala: Marsupial (not placental).
$4$. Anteater: Placental mammal.
$5$. Lemur: Placental mammal.
$6$. Wolf: Placental mammal.
$7$. Tasmanian tiger cat: Marsupial (not placental).
$8$. Sugar glider: Marsupial (not placental).
The placental mammals are: Mole,Anteater,Lemur,and Wolf.
Total count = $4$.

(D) Convergent evolution occurs when unrelated species evolve similar traits as a result of having to adapt to similar environments or ecological niches.
In the given options,the Flying Squirrel (a placental mammal) and the Sugar Glider (a marsupial mammal) are unrelated species that have evolved similar adaptations for gliding,which is a classic example of convergent evolution.
Other pairs like Koala and Kangaroo,Mouse and Flying Squirrel,or Bobcat and Wolf represent adaptive radiation within the same lineage (marsupials or placentals),not convergent evolution between different lineages.

(C) After the continental drift,Australia separated from the other landmasses.
Due to this isolation,the marsupials in Australia were protected from competition with placental mammals,which were more evolutionarily advanced and dominant in other parts of the world.
Consequently,the marsupials evolved and diversified in Australia without facing significant competition,allowing them to survive and thrive.

(A) Adaptive radiation is the process of evolution of different species in a given geographical area starting from a point and radiating to other areas of geography (habitats). In Australia,marsupials show adaptive radiation,where they evolved into various forms similar to placental mammals.
Matching the organisms:
- $(a)$ Anteater corresponds to $(iv)$ Numbat.
- $(b)$ Mouse corresponds to $(i)$ Marsupial mouse.
- $(c)$ Mole corresponds to $(iii)$ Marsupial mole.
- $(d)$ Lemur corresponds to $(ii)$ Spotted cuscus.
Therefore,the correct matching is $a-iv, b-i, c-iii, d-ii$.

(B) The birds shown in the figure are known as Darwin's finches. Charles Darwin observed these birds during his voyage on the $HMS$ Beagle to the Galapagos Islands. He noticed that there were many varieties of finches in the same island,all evolving from a common ancestor. This phenomenon is a classic example of adaptive radiation,where species diversify from a common ancestral form into different forms adapted to specific environmental niches.

(C) The animal shown in the figure is a Sugar glider.
Adaptive radiation is the process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography (habitats).
Australian marsupials exhibit adaptive radiation.
When more than one adaptive radiation appeared to have occurred in an isolated geographical area (representing different habitats),one can call this convergent evolution.
Placental mammals in Australia also exhibit adaptive radiation in evolving into varieties of such placental mammals each of which appears to be 'similar' to a corresponding marsupial (e.g.,Placental wolf and Tasmanian wolf-marsupial).
The Sugar glider is a marsupial that shows convergent evolution with the placental Flying squirrel.

(A) The correct answer is option $A$ because the process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography is called adaptive radiation.
$Saltation$ is a single-step large mutation.
When one organism evolves with respect to evolution in another organism,it is called co-evolution. For example,the host-parasite relationship.
Natural selection is the process through which a population of living organisms that adapt are selected by nature based on reproductive fitness.

(A) Adaptive radiation is an evolutionary process in which organisms diversify rapidly from an ancestral species into a multitude of new forms,particularly when a change in the environment makes new resources available,creates new challenges,or opens new environmental niches.
This process leads to the development of new species that are adapted to different habitats and ways of life,representing a form of divergent evolution.

(A) The origin of different types of beaks,as famously observed by Charles Darwin in the Galapagos finches,is primarily driven by natural selection.
While variations exist within a population,the environment imposes specific pressures.
Individuals with beak shapes better suited to the available food sources in their specific habitat have a higher survival and reproductive success rate.
Over generations,these advantageous traits are selected and become more prevalent in the population,leading to adaptive radiation.

(A) Darwin's finches are a classic example of adaptive radiation,which serves as evidence for evolution through biogeographic distribution.
$(i)$ Darwin observed that different species of finches on the Galapagos Islands evolved from a single ancestral species that migrated from the mainland.
$(ii)$ The diversification occurred due to different environmental pressures in various habitats,leading to distinct beak adaptations.
$(iii)$ This pattern of distribution and diversification based on geographical isolation is a key component of biogeographic evidence for evolution.

(C) Continental drift is the phenomenon that caused the separation of landmasses. Due to this,Australia became isolated from other continents. As a result,the pouched mammals (marsupials) of Australia survived and diversified in the absence of competition from placental mammals,which were evolving and dominating in other parts of the world.

(B) Darwin's finches are a classic example of adaptive radiation. These birds evolved from a common ancestral species on the Galapagos Islands. Due to the separation of the islands,the populations became geographically isolated,leading to divergent evolution and the formation of distinct species adapted to different food sources.

(C) When unrelated groups of organisms evolve similar adaptive functional or structural features due to similar environmental pressures,it is known as convergent evolution. This process is also referred to as adaptive convergence. Therefore,both terms describe the same phenomenon.

(D) Darwin's finches are a classic example of adaptive radiation. The original ancestral species that migrated to the Galapagos Islands from the South American mainland were seed-eating birds. Over time,these birds evolved into various species with different beak shapes adapted to different food sources,such as insects,cactus fruits,or seeds.

(A) Lemurs are placental mammals found in Madagascar,while the Spotted cuscus is a marsupial mammal found in Australia.
These two organisms belong to different lineages but have evolved similar adaptive features to survive in similar ecological niches.
This phenomenon,where unrelated organisms evolve similar traits due to adaptation to similar environments,is known as convergent evolution.
Therefore,Lemur and Spotted cuscus exhibit convergent evolution.

(D) Darwin's finches are a group of small black birds that Charles Darwin observed during his voyage to the Galapagos Islands. He noted that these birds had evolved different beak shapes adapted to various feeding habits,which provided significant evidence for the theory of adaptive radiation and natural selection.

(D) Tasmanian wolf (a marsupial) and placental wolf (a placental mammal) are examples of convergent evolution. Even though they belong to different lineages,they have evolved similar phenotypic traits due to adaptation to similar environmental niches.

(D) Adaptive radiation is the process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography (habitats).
Darwin's Finches in the Galapagos Islands are a classic example where many varieties of finches evolved from a single ancestral species.
Similarly,Australian marsupials represent adaptive radiation as they evolved into various forms from a common ancestral stock.
Wolf and Tasmanian Wolf are examples of convergent evolution,not adaptive radiation,as they are unrelated species that evolved similar traits independently.

(B) When more than one adaptive radiation occurs in an isolated geographical area (representing different habitats),it leads to the evolution of different groups of organisms that resemble each other due to similar environmental pressures. This phenomenon is known as $Convergent$ $evolution$. $A$ classic example is the evolution of $Placental$ $mammals$ and $Australian$ $marsupials$,which show striking similarities despite being evolutionarily distinct.

(A) During the process of continental drift,Australia separated from other landmasses. This geographical isolation prevented the migration of placental mammals into Australia,thereby reducing competition for the pouched mammals (marsupials). As a result,marsupials evolved and diversified in Australia without significant competition from placental mammals. Therefore,both the Assertion and the Reason are correct,and the Reason provides the correct explanation for the Assertion.

(A) Adaptive radiation refers to the process of evolution of different species in a given geographical area starting from a point and radiating to other areas of geography (habitats).
When more than one adaptive radiation appears to have occurred in an isolated geographical area (representing different habitats),one can call this convergent evolution.
Placental mammals in Australia also exhibit adaptive radiation in evolving into varieties of such placental mammals,each of which appears to be similar to a corresponding marsupial (e.g.,Placental wolf and Tasmanian wolf).
Thus,both the Assertion and the Reason are correct,and the Reason provides the correct explanation for the Assertion.

(A) Adaptive radiation is the process of evolution of different species in a given geographical area starting from a point and radiating to other areas of geography (habitats).
Australian marsupials are a classic example of adaptive radiation,where a number of marsupials,each different from the other,evolved from an ancestral stock within the Australian island continent.
Both the spotted cuscus and the marsupial mole are native marsupials of Australia,confirming that they are products of this specific adaptive radiation.
Therefore,both the Assertion and the Reason are correct,and the Reason provides the correct context for the Assertion.