Adaptation for Survival (Competition)

Competition

Competition is the process by which living organisms in the habitat struggle with one another
for limited essential needs in the environment. Such scarce resources in plants include; light,
space, nutrient and water while animals compete for food, space or mate.

Competition finally results in survival of the fittest and elimination of the unfit.

Types of competition

1. Intraspecies competition: competition between organisms of the same species. e.g.

many maize seedlings grown in a small area.
2. Interspecies competition: that between different species of organisms. e.g. many
maize and pepper seedlings growing in a small area.

Relationship between competition and succession

Succession is the change in a population caused by the replacement of the old members with
new ones as a result of competition. The newly formed habitat is gradually colonized by
different species of plants in a stepwise manner until a relatively stable community is
established and later the habitat will be inhabited by animals. As soon as habitat is
established, competition sets in. The early inhabitant modifies the habitat by their activities
while the later arrivals compete and outgrow the previous inhabitants which gradually loss
out.
Adaptation

Adaptation is the possession of special features which improve the chances of an organism to
survive in its environment. All organisms have adaptive structures which could be structural
or morphological and behavioural in nature. These enable them to live successfully in their
habitat.

There are three modes of adaptation:

1. Structural adaptation
2. Adaptive colouration
3. Behavioural adaptation

Structural adaptation:

This is a special modification of structures which help organisms to survive better in their
environment. Examples include;

1. Structural adaptation to obtain food: e.g. a toad has a long tongue to catch its prey;
birds have sharp, strong and curved claws for catching their prey; Insects have
modified mouthparts for feeding; Insectivorous plants (e.g. Utricularia sp i.e.
bladderwort, Droseria sp i.e. sundew, etc) have special structural adaptive features.
2. Structural adaptation for escape and defence: Escape adaptation can be grouped
into camouflage (concealing colouration), individual and group responses e.g.
caterpillars taking the colour of leaves. Defence adaptation may be in form of physical
structure e.g. spines and shell, scales etc., chemical defence e. g. snakes attack their
enemies by spitting venom, bees and scorpion have stings and mimicry (looking like
an uninteresting object) e. g. stone plant.
3. Structural adaptation to attract mates: e.g. Adult male agama lizard displays its
bright colour to attract its mates, flowering plants attract insects for pollination, bright
coloured feathers of male domestic fowls and peacock etc.
4. Structural adaptation to regulate body temperature: e.g. mammals have a fat
layer, sweat gland, feathers and subcutaneous fat in birds in birds etc. All serve to
regulate heat loss.
5. Structural adaptation for water conservation: e.g. some plants have small needle-
like leaves (conifers), thick bark (acacia), waxy cuticles etc. to reduce the rate
transpiration. Likewise, some animals possess scales, exoskeleton, feathers etc. to
reduce water loss.
Adaptive colouration
This is the possession by an organism of a colour which enables it to catch its prey,
avoid its predators or enemies, secure mates and ensure their survival. Adaptive
colouration may be grouped into
1. Concealing (cryptic) colouration to help organisms blend with their
background and remain unnoticed by predators
i. Colour blendingwith the environment e. g. green cuticles of grasshopper,
green snakes etc.
ii. Counter shading by animals possessing a dark dorsal surface and light
ventral surface as in tilapia fish to remain unnoticed by predator above and
below.
iii. Colour change(camouflague)to match the environment as in
chameleon, grasshopper etc.
iv. Disruptive colouration as patterns to break the body outline of animals
against the dark and light shades of their backgroung as in giraffe, leopard,
tiger, lady bird beetle etc.
2. Warning colouration to announce the presence of the organism(s) to
potential predator to avoid them because they have some unpleasant features e.
g. variegated grasshoppers, black and yellow bands of wasps.
3. Mating colouration as in male agama lizard, peacock.
4. Mimicry in harmless organisms resembling a distasteful or harmful one
for the enemies to avoid such e.g. stick insects, swallow tail butterfly.
5. Bright colouration of insect pollinated flowers and pitchers of insectivorous plants.

Behavioural adaptation

Behaviour is basically adaptive, everything used by organisms to promote their survival.

Examples include:

1. Behavioural adaptation in predators e.g. Lion with high speed chases its prey; spider
spins its webs for its prey
2. Behavioural adaptation to protect prey from predators e.g. bats hold tree branches
with heads upside down (which is described as swaying in the air), Antelopes escape
with speed, beetles secrete offensive odour, toad puffs itself up
3. Behavioural adaptation for avoiding harsh weather conditions e.g. such as
aestivation; a state of inactivity and reduced metabolism (dormancy) that animals
experience in response to hot and dry conditions , while Hibernation occurs in the
winter (low temperature) e.g insect-eating bats; migration of certain animals (e.g.
cattle egrets) to favourable habitats
4. Behavioural adaptation in plants: e.g. some plants shed leaves in the dry season
(deciduous plants); some like yam tuber, potatoes die down and survive as
underground stem; plant seeds can remain dormant, plant shoot moves towards the
light (Positive phototropism)
5. Gregarious behaviour (movement in groups) is expressed by elephants zebra, birds,
fishes, social animals (bees, termites) etc.
Social animals

Social animals are those in which individuals of the same species live together cooperatively
in organized communities known as societies (colonies). Examples of social animals are
social insects (like termites, honey bees or wasps, ants etc), wolves, foxes, baboons etc.

Characteristics of Social Insects

1. They live together

2. They display division of labour
3. They show distinct castes
4. Members communicate with one another within the colony.

Termites

Habitats of termites

They are found living together in large communities in a nest which may be tunnels in
deadwood or ant hills (termitaria).

Note- Termites are blind: they communicate through touch and smell.

Castes of termites

They have three castes: The reproductive, soldiers, workers.

1. The reproductive is of three types: king, queen and winged reproductive. The king
has no wing, is smaller than the queen and it fertilizes the queen. The queen has a
small head, small thorax and large abdomen. It is the largest of all the castes. Only
one queen at a time is found in a colony. The queen lays eggs. The winged
reproductive are fertile and are potential kings and queens of new colonies.
2. The soldiers are sterile, wingless and blind. They have big heads with stony maxillae
and mandibles. Soldiers are of two types: (i) The mandibulate soldiers with strong
mandibles and (ii) Nasute soldiers with projective mouth paths. The soldiers defend
the colony against enemies.
 3. The workers are wingless, blind, and sterile. They form the majority in the colony
and possess well-developed mouth paths. They build and repair the termitaria; provide
food for colonial members; look after the eggs laid by the queen and baby termites
(nymphs). They feed the nymphs and the queen and cultivate fungus gardens.

Life history of termites

Termites exhibit incomplete metamorphosis i.e.

Egg —– nymph—–adults

The nymphs develop into soldiers and reproductive. And those which fail to develop become
workers. When the winged reproductives are mature, they exhibit nuptial or wedding flight
i.e. swarming out from the existing colony to build new ones.

Behavioural adaptation of termites for survival

1. They move in groups to ward off their enemies

2. They have a wide variety of diet; feeding on both living and dead plants.
3. They burrow into the soil or wood to build tunnels for protection against their
enemies.
4. The habit of feeding on dead members helps to keep the colony clean.
5. Their ability to massive production of offsprings promotes their survival.

Economic importance of termites

1. Termites while building their tunnels help in loosening and mixing the soil.
2. They decompose wooden materials as they feed.
3. They add humus to the soil through their decomposition activities.
4. They act as a good source of protein and fat.
5. The anthill clay can be used to build the surface of a tennis court.

Honey bees
Habitat of Honey bees

These are social insects living in hives made up of chambers or cell.

Castes of honey bees

The bee colony has 3 castes, namely:

 The drone (in hundreds per colony)

 The queen (only in 1 per colony)
 The workers (in thousand per colony)

1. The drone is winged with shorter abdomen than the queen but bigger than the
workers. The drone mates with the queen during the nuptial flight after which it dies.
2. The queen is a fertile female, winged and much bigger than the workers. It is fed with
royal jelly and lays an egg.
3. The worker is a sterile female, winged and is smaller than the queen or drone. It
possesses eyes and a sting. Also with modified mouth paths for collecting nectar and
building the hive. The workers’ legs are also modified for collecting pollen grains
from flowers. The workers perform a special dance called rail wagging as it locates a
food source. The workers secrete wax for building the hive, ventilate the hive and
clean the cells, guard the hive, make honey from nectar and pollens and feed the
larvae with royal jelly or honey.

Economic importance of honey bees

1. They help to pollinate flowers.

2. They produce honey which has high nutritive and medicinal value.