Ecology 3 - Adaptation

Biotic factor

Living factors

Abiotic

Non-living factors

Adaptations

Characteristics (structural or behavioural), that allow an organism to survive in their habitat. They are specific to abiotic and biotic pressures.

Adaptations of the ringed seal

1. Streamlined body shape → low-drag reduces water resistance for faster energy-efficient movement

2. Blubber layer → Thick fat layer provides insulation in cold water + buoyancy

3. Flippers/propulsion → Pushes against water viscosity for efficient movement

Adaptations of the black-throated loon

1. Streamline body → reduces air and water resistance

2. Feathers → Traps insulating air, coated in hydrophobic oil to keep dry + retain heat

3. Webbed feet → Propulsive drag

4. Hollow bone → reduced mass for increased buoyancy during flight

Adaptations of lyme grass

Habitat: Sand dune

1. Thick waxy cuticle on leaves → Reduces water loss via transpiration

2. Rollable leaves → Internal humid chamber + reduce SA to wind

3. Rhizomes (underground stems) → grow upwards during sand accumulation to stabilise + extend deep into dune to reach water

Sand dune habitat features

1. High wind accelerates evaporation

2. High salinity → hard to absorb water

3. Sand holds little water due to low organic matter

4. Sand accumulation → buries/uproots plants and shifts ground beneath them

5. Fructan (carbs) accumulation in root/cells → Increases cell osmotic potential to pull water against concentration gradient

Mangrove swamps habitat features

1. Sheltered coastal environment

2. Flooded with seawater at high tide

3. Waterlogged anaerobic soils

4. Mud has high salt concentrations (2x higher than ocean due to daily flooding, and salt accumulates overtime)

Adaptations of a mangrove tree

• Salt glands in leaf → secretes excess salt to maintain safe internal salt balance

• Pneumatophores → vertical root branches to absorb atm. oxygen

• Large, buoyant seeds → float easily so they can be dispersed by ocean currents

Distribution

The geographical area where a species can be found

Abiotic factors affecting plants

1. Temperature

2. Precipitation

3. Water availability

4. Soil pH

5. Soil salinity

6. Availability of soil minerals

7. Light intensity

8. Altitude

Abiotic factors affecting animals

1. Temperature

2. Water availability

3. Altitude

4. Water turbidity/pH (fish)

Range of tolerance

A species’ ability to survive is limited to a narrow range of an abiotic factor

Transects

Assess species distribution in correlation with any abiotic factor that varies across a measurable distance. They show us tolerance.

Belt transects

Abundance of species is estimated using quadrats placed at regular intervals along the belt

Kite graphs

Show the abundance of organisms over a transect

Relative width of a kite = Abundance of a species

Coral & Zooxanthellae algae

Coral: Provides protected environment and Co2 for photosynthesis

Algae: Provides Oxygen and glucose from photosynthesis

Abiotic factors for Coral Reefs

1. Depth = Shallow for light penetration

2. pH = Above 7.8 to prevent bleaching

3. Salinity = 32-42%

4. Clarity of water = Clear for light penetration

5. Temperature = 20-28°C

Obligate aerobes

Require continuous oxygen supply and can only live with environments with oxygen

Obligate anaerobes

Inhabited or killed by oxygen, can only live in anoxic environments

Faculative anaerobes

Uses oxygen if its available and can live in oxic or anoxic environments

Anoxic environements

• Swamps

• Waterlogged soil/mud

• Intestinal tracts

• Bottom of lakes or oceans

Winogradsky columns

A type of mesocosm built of:

• Water

• Mud

• Paper towels + Mud + CaSO4 + CaCO3

When light hits the column, over time different communities of microorganisms will form

Adaptations of Trees

1. Tall trunks → thick trunks withstand wings and prevent collapsing, and height outcompetes other trees

2. Broad crown → wide exposure of leaves to light

3. Mosaic positioning of leaves → reduces self-shading so upper leaves don’t block light for leaves below

Adaptations of Lianas

1. Fast vertical growth → bypasses competition on forest floor

2. Climbing structures → tendrils or hooks to anchor onto host trees

3. Flexible stems → sway with movement of trees without breaking

4. No trunks → investment in trunks are redirected to vertical growth

Adaptations of Epiphytes

1. Aerial roots → absorb moisture and nutrients from the air

2. Waxy, thick leaves → reduces water loss

Epiphytes

Grow on the surface of trees to avoid competition on the forest floor, they gain more light exposure, but have scarce water and nutrients up the canopy

Lianas

Woody vines that use existing trees for support, reaching the canopy without building their own trunks

Adaptations of Stranglers

1. Roots grow downwards to floor → gain nutrients from soil while at high heights

2. Growth upwards and downwards → when roots thicken around the tree trunk, it constricts the trunk and blocks flow of water and light exposure (tree decays and dies)

Stranglers

Epiphytes that begins its life growing on top of another tree, eventually encasing and killing the host with its roots

Adaptations of Shade Tolerant Plants

1. Contains different photosynthetic pigments → absorbs wavelengths canopy has not already taken

2. Large leaves → maximises surface area

3. Brightly coloured/strong scented flowers → attract pollinators under low light

Niche

The role of a species within its habitat, taking into account the biotic and abiotic interactions of the species

Fundamental niche

The full range of conditions and resources in which a species could survive and reproduce, based on its adaptations and tolerance limits

Realised niche

Actual conditions and resources in which a species exists, due to biotic interactions

Compare and Contrast: Realised v Fundamental

Potential distribution vs Actual distribution

No competition vs Yes competition

No predation vs Yes predation

Large in range vs Small in range

Competitive exclusion

Elimination of a competing species from its niche

Herbivore adaptations

1. Mouthparts → biting/chewing leaves or tubular mouthparts to reach phloem sap

2. Metabolic adaptations for detoxifying toxins found in leaves

Plant adaptations against herbivory

Physical/Mechanical

• Sharp spines, thorns → Cacti

• Thick bark to prevent piercing of stems

Or they have toxic compounds

Plant-herbivore specificity

Only a few species of herbivores are adapted to feed on a particular plant

Types of Adaptations

1. Structural

2. Chemical

3. Behavioural

Structural adaptations

Physical features of an organism that enhance its survival and reproductive success

e.g morphology, camouflage

Behavioural adaptations

Actions or behaviours that organisms engage in to survive and reproduce, often responses to stimuli

e.g migration, hibernation

Physiological/Chemical adaptations

Internal processes and functions that enhances an organism’s ability to cope with environmental challenges

e.g Thermoregulation, metabolic adaptations

Hedgehog adaptations (Prey)

Structural → Sharp keratin spines covering the back to deter predators

Behavioural → Rolling into a tight ball when threatened to protect vulnerable areas

Chemical → Resistance to toxins, allowing them to safely eat venomous insects

Electric eel (Predator/Prey)

Structural → Long cylindrical body with specialised organ cells that act like batteries (generates, stores and releases bursts of electricity)

Behavioural → Emits low-voltage pulses to scan their environments for nearby animals in the dark

Chemical → Highly specialised electrolytes that generate high voltages of electricity to stun prey/threats

Dentition

The number, type, and arrangement of teeth in the mouth of a person or animal

4 types of teeth

Premolars

Incisors

Molars

Canine

Incisors

Cutting and biting into food

Canines

• Tearing and ripping flesh

• Weapons against predators

• Social display of aggression/dominance

Premolars and molars

Grinding and shearing food

Family hominidae

Humans, orangutang, bonobo, gorilla, chimpanzees

Some are exclusively herbivores and others are omnivorous

Herbivore denition

• Usually no canines → may lack certain teeth

• Predominantly flat and high-crowned molars for grinding

• Incisors absent or specialised for cropping

• Horizontal jaw motion (grinding)

Omnivore denition

• Small/moderate canine for tearing

• Both sharp and flat molars

• Chisel-like incisors for biting plant and animal matter

• More complete set of teeth

• Vertical shearing and horizontal grinding jaw motion

Gorillas

• Massive, broad and flat molars with high ridges

• Diet: tough celery-like stalks, bamboo, leaves

• Males canines are for defense and social display to attract/protect females

Biome

Groups of the same ecosystem due to similar abiotic conditions, determined primarily by temperature and rainfall

Convergent evolution

Unrelated species independently develop similar traits in response to similar environmental challenges or selective pressures

Analogous structures

Result of convergent evolution, similar function but different structure

Convergent evolution due to biome

• Plants/animals evolve adaptations due to abiotic factors

• Biomes, even in different regions, have the same abiotic factors

• So, organisms will evolve similar adaptations

Cobras (Predator, chemical)

Produce neurotoxic venoms which interfere with the passage of nerve impulses in prey

Bluffing technique (Prey, behavioural)

Hognose snakes pretend to be dead

Frill-necked lizards use their neck frill to pretend to be larger than they really are

Canopy

Uppermost layer of plants made up of trees

Cacti (adaptation to hot desert biome)

• Stem with thick waxy cuticle → reduces water loss

• Spines instead of leaves → reduces water loss and grazing

• Shallow surface roots → fast absorption of any water from rainfall

• Deep tap root → enables access to water hidden in sand + supports cacti structure

Kangaroo rats (hot desert biome)

• Spend daylight hours in underground burrows → avoid excessive heat

• Produces highly concentrated urine → minimise water loss

Kapok tree (adaptation to tropical biomes)

• Rapid growth → outcompete other species

• Wide buttress roots → sturdy base to support trees

Orchid mantis (tropical biomes)

• Adult female looks like orchid flower → mimicry to attract insect pollinators to catch and eat

• Male orchid is smaller and plainer → allows camoflage

Why would there be differences in jaws/beaks?

They are adapted to different diets

What other structure can scientists check apart from dentition when searching for diets?

Skeletal structure → jaw/skull features to infer if animal was adapted for tearing meat or grinding plants