Natural Selection

Genetic Diversity

The total amount of genetic variation that exists within a population or species

The variety of different genes and alleles within a population or species.

Example: A population of rabbits has different fur colours, such as brown, white and black, because of genetic variation.

Easy way to remember: Genetic diversity = differences in genes between individuals of the same species.

Phenotypic difference

An observable difference between individuals, caused by different genotypes

Phenotypic difference: An observable difference in the characteristics of individuals, caused by genetic differences and/or environmental factors.

Examples:

• Different fur colours in rabbits.

• Different heights in humans.

• Different flower colours in plants.

Easy way to remember: Phenotypic difference = differences you can observe in an organism's characteristics.

Difference between genetic diversity and phenotypical differences

• Genetic diversity = differences in the genes of individuals within a population.

• Phenotypic differences = observable differences in the characteristics of individuals.

Example: Rabbits have different genes for fur colour (genetic diversity), which can result in brown, white or black fur (phenotypic differences).

What are adaptations?

Characteristics or behaviours that help an organism survive and reproduce in its environment.

Types of adaptations

•structural

•behavioural

•Functional/physiological

What are structural adaptations

Physical features of an organism (that  you can draw)

Examples:
Polar bears have thick fur to keep warm.

Ducks have webbed feet to help them swim.

Cacti have spines instead of leaves to reduce water loss.

Giraffes have long necks to reach leaves high in trees.

What are behavioral adaptations?

A way an organism acts or behaves that helps it survive and reproduce in its environment.

Examples:
Birds migrating to warmer places during winter.

Bears hibernating during winter to conserve energy.

Nocturnal animals being active at night to avoid daytime heat.

Meerkats taking turns watching for predators to protect their group.

What are functional/physiological adaptations?

An internal body process or function that helps an organism survive in its environment.

Examples:
Camels producing concentrated urine to conserve water.

Snakes producing venom to capture prey.

Humans sweating to cool down their bodies.

Some animals producing antifreeze proteins to survive freezing temperatures.

Easy way to remember adaptations types and definitions

• Structural = what an organism has (physical features).

• Behavioural = what an organism does (actions).

• Physiological = how an organism's body works (internal processes).

Types of camouflage

Concealing coloration is the most common, where the organism resembles its surroundings in coloration, form or movement. An example would be the earth-tone colors of a white-tailed deer or the swaying walking pattern of a walking leaf insect.

Disruptive coloration allows the organism to disguise its identity or location so that predators misidentify what they are seeing. For example, a zebra has a black and white stripe pattern. This pattern makes it extremely difficult for a predator to stalk one zebra, as the patterns of the herd blend together. Another example is the eye spot on some butterfly wings. The eye spot can be misinterpreted as an eye of a larger animal like an owl or can misdirect the predator to attack a less vulnerable body part, providing the prey with an opportunity to escape.

Self-decoration is the act of hiding and concealing body features. Organisms, like the dresser crab, decorate themselves to match the background. The dresser crab obtains pieces of coral or sponge and affixes them onto hooked hairs that cover its body. This allows the dresser crab to blend into the seafloor and be overlooked by a predator.

What is a hybrid

An individual produced by a cross between parents of different genotypes; often used to refer to the offspring of two different species.

What is artificial selection?

The process by which people choose to bred particular organisms with desirable features