Which one of the following shows a unique relationship with an insect that has coevolved with it and that is the only insect that ta pollinate this tree ?
Contents16
- AFig
- BMahua
- CSandalwood
- DSilk cotton
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Answer: (A) Fig
Correct Answer: (a) Fig.
Fig trees have a unique co-evolved relationship with fig wasps.
Each species of fig tree has its own specific partner wasp species — no other insect can pollinate that particular fig.
How it works:
- The female wasp enters the fig to lay eggs, and while doing so, she pollinates the flowers inside.
- In return, the fig provides some of its developing seeds as food for the wasp larvae.
This is one of the best examples of mutualism and co-evolution in nature.
Key fact: This is a one-to-one relationship — one fig species = one specific wasp species.
Fig trees and fig wasps show perfect one-to-one coevolution where each fig species has exactly one wasp species that can pollinate it, making this relationship completely unique in nature.
This represents obligate mutualism where both species cannot survive without each other - the wasp needs the fig's seeds to reproduce, and the fig cannot be pollinated by any other insect.
The question tests understanding of specific plant-pollinator relationships versus general pollinators that work with multiple plant species.
Fig-Wasp Coevolution
Environment Fig insect pollinate
Fig-Wasp Coevolution: Nature's Perfect Partnership
Each fig species has its own specific wasp species — no other insect can pollinate that fig
Female wasp enters fig to lay eggs and simultaneously pollinates the flowers inside
Fig provides developing seeds as food for wasp larvae in return
This is obligate mutualism — both species cannot survive without each other
What Makes This Unique
Fig trees (Ficus species) show the most specialized pollination relationship in nature. Unlike other trees that rely on multiple insect species, each fig species has coevolved with exactly one wasp species over millions of years.
The Pollination Process
%%{init: {"flowchart": {"wrappingWidth": 460}}}%%
flowchart TD
s1["`**Female wasp enters fig**
Wasp squeezes through tiny opening in the fig, often losing wings and antennae`"]
s2["`**Pollination occurs**
While moving inside, wasp transfers pollen from her birth fig to female flowers`"]
s3["`**Egg laying**
Wasp lays eggs in some of the fig's ovules using her ovipositor`"]
s4["`**Wasp dies inside**
Female wasp dies after completing her reproductive cycle`"]
s5["`**Next generation emerges**
New wasps develop, mate inside fig, and females leave carrying pollen to repeat cycle`"]
s1 --> s2
s2 --> s3
s3 --> s4
s4 --> s5Why This Coevolution Happened
Figs have enclosed inflorescence — flowers are inside the fruit, inaccessible to most pollinators
Only tiny wasps can squeeze through the ostiole (small opening) in the fig
This created evolutionary pressure for size matching between wasp and fig opening
Chemical signals evolved so wasps can identify their specific fig species
Timing synchronized so wasps emerge when figs are ready for pollination
Other Options Comparison
Tree | Pollination Type | Key Pollinators | Relationship |
|---|---|---|---|
Fig | Obligate mutualism | Species-specific wasps | One fig = One wasp species |
Mahua | Generalist | Bees, beetles, flies | Multiple pollinator species |
Sandalwood | Wind + insects | Various small insects | Non-specific relationship |
Silk cotton | Bird pollination | Sunbirds, crows, parrots | Multiple bird species |
Fig Structure
Source: ScienceDirect.com — Fig Wasp - an overview | ScienceDirect Topics · www.sciencedirect.com
Trap: Mahua (Madhuca longifolia) is pollinated by multiple insects, not one specific species
Trap: Sandalwood is semi-parasitic but has no unique pollinator relationship
Trap: Silk cotton has showy flowers for bird pollination, not insect-specific coevolution
Remember: Only figs show true obligate mutualism with one-to-one species matching
Coevolution and Mutualism
Environment coevolved unique relationship
Coevolution and Mutualism: When Species Evolve Together
Coevolution occurs when two species evolve in response to each other over time
Mutualism is interaction where both species benefit from the relationship
Obligate mutualism means neither species can survive without the other
Fig-wasp relationship is the classic example of coevolved obligate mutualism
Understanding Coevolution
Coevolution happens when species exert selective pressure on each other, leading to reciprocal evolutionary changes. The fig-wasp system evolved over 60+ million years, with each partner becoming increasingly specialized.
Types of Mutualism
Type | Definition | Example | Dependency Level |
|---|---|---|---|
Obligate | Neither can survive alone | Fig-wasp, Lichens | Complete dependency |
Facultative | Beneficial but not essential | Ant-acacia, Bee-flower | Partial dependency |
Defensive | Protection in exchange for resources | Clownfish-anemone | Moderate dependency |
Coevolution Examples
# Coevolved Relationships
## Plant-Pollinator
- Fig-wasp (obligate)
- Yucca-yucca moth
- Orchid-specific bees
## Predator-Prey
- Cheetah-gazelle speed
- Snake venom-prey resistance
- Butterfly-bird coloration
## Host-Parasite
- Virus-host immunity
- Cuckoo-host birds
- Plasmodium-mosquitoSigns of Coevolution
Morphological matching — body parts fit together perfectly (wasp size = fig opening)
Chemical communication — species recognize each other through specific compounds
Synchronized timing — life cycles coordinated for optimal interaction
Geographic correlation — species distributions overlap precisely
Evolutionary arms race — continuous adaptation and counter-adaptation
Don't confuse coevolution with simple adaptation — coevolution requires reciprocal changes
Obligate vs facultative mutualism — only obligate means both species are completely dependent
Not all plant-pollinator relationships show coevolution — most are generalist systems
Commensalism (one benefits, other neutral) is different from mutualism (both benefit)
Plant-Pollinator Relationships
Environment pollinate tree
Plant-Pollinator Relationships: Strategies for Reproduction
Most plants use generalist pollination — multiple species can pollinate them
Specialist pollination like fig-wasp is rare but highly efficient
Flower characteristics determine which pollinators are attracted
Pollination syndromes are flower traits that match specific pollinator types
Pollination Strategies
Plants evolved different strategies to ensure cross-pollination. Most use generalist approach with multiple pollinator species, while few like figs developed specialist relationships with single species.
Pollination Syndromes
Syndrome | Flower Traits | Pollinator | Examples |
|---|---|---|---|
Entomophily | Bright colors, nectar, fragrance | Insects (bees, beetles, flies) | Most flowering plants |
Ornithophily | Red/orange, tubular, abundant nectar | Birds (sunbirds, hummingbirds) | Silk cotton, Coral tree |
Chiropterophily | White/pale, strong scent, night blooming | Bats | Baobab, some palms |
Anemophily | Small, no petals, light pollen | Wind | Grasses, conifers |
Specialized | Species-specific traits | One pollinator species | Fig trees |
Indian Examples
Mahua (Madhuca longifolia) — generalist entomophily, attracts bees, beetles, and flies
Silk cotton (Bombax ceiba) — ornithophily, red flowers attract sunbirds and crows
Sandalwood (Santalum album) — small flowers, wind and insect pollinated
Fig species in India — each has specific wasp partner, over 100 fig species recorded
Areca palm — wind pollinated, though some insects also visit
Pollination Process
%%{init: {"flowchart": {"wrappingWidth": 460}}}%%
flowchart TD
s1["`**Flower produces attractants**
Nectar, pollen, fragrance, or visual signals to attract pollinators`"]
s2["`**Pollinator visits flower**
Drawn by rewards, pollinator contacts reproductive parts`"]
s3["`**Pollen pickup**
Pollen grains stick to pollinator's body (intentionally or accidentally)`"]
s4["`**Movement to next flower**
Pollinator carries pollen while seeking more rewards`"]
s5["`**Pollen transfer**
Pollen deposited on stigma of new flower, enabling fertilization`"]
s1 --> s2
s2 --> s3
s3 --> s4
s4 --> s5Mahua flowers attract multiple insects — not species-specific like figs
Bird pollination doesn't mean coevolution — silk cotton uses many bird species
Wind pollination is common in gymnosperms and grasses, rare in colorful flowers
Don't assume large/showy flowers mean specialist pollination — often the opposite