Adaptations and natural selection

Adaptation.mp4

Plant Adaptations.mp4

Water.mp4

Changes (3).mp4

Natural Selection.mp4

Genetic Mutations.mp4

Camoflauge.mp4

Hibernation.mp4

Evolution.mp4

Adaptation

An adaptation is a modification or change in the organism's body or behavior that helps it to survive.

Physical Adaptation: a change in the animals body and/or appearance that improve that animals survival.

ex. wolves grow a thick coat to keep warm in the winter

Behavioral Adaptation: a change in the animals actions that improve that animals survival.

ex. geese fly south to warmer places for the winter

Why animals adapt in order to survive:

- climatic conditions in their ecosystem
- against predators
- against other species that compete for the same food and space

Mimicry: when an animal acts like another animal or plant in order to survive (trick used against predators)

Camouflage: when an animal blends into its surroundings in order to survive (trick used against predators)

Hibernation: when animals prepare and sleep during the winter in order to survive. They avoid having to search for food and find ways to stay warm.

Migration: when animals travel to warmer places during the winter, in order to survive. They avoid the cold and have easier access to food.

Locomotion: when an animal can move in a way to help it survive

Predator: animals that target specific animals (prey) for food

Prey: animals that are the target of specific animals (predators)

Reproductive Success

Animals increase their reproductive success when they have offspring that survive to reproduce.

Animals can increase their chances of having offspring by behaving in ways that help them get partners to mate and reproduce with. These partners are called mates. For example, animals may make special sounds, perform specific dances, or show off bright colors to attract mates. Animals may also compete with each other for mates.

Animals can increase the chances that their offspring will survive to reproduce by caring for and protecting them. For example, animals may feed their offspring or guard them from predators. These behaviors increase the chances that the offspring will survive to adulthood, when they can reproduce.

Many behaviors can increase the chances that animals will have offspring that survive to reproduce. But the behaviors cannot guarantee that the animals will have greater reproductive success. Animals that attract or compete for mates won't always successfully mate and reproduce, and offspring that are fed and protected won't always survive to adulthood.

Variations

A population is a group of individuals of the same species that live in the same place. The individuals in a population often have differences in their traits. These differences are called variations.

Natural Selection

In a population, there may be more individuals with one variation of a trait than with other variations. A variation can become more common in the population due to a process called natural selection.

Natural selection causes advantageous inherited variations to become more common in a population over time. Whether a variation is more or less advantageous depends on the population's environment.

A variation is more advantageous in an environment if it makes an individual more likely to survive or reproduce in that environment. Advantageous variations may make it easier for an individual to get food, avoid predators, or benefit from other conditions in the environment.

Total Population

The individuals in a population have different traits. The percentage of the population with a certain trait tells you how much of the population has that trait. You can use the following equation to find this percentage.

percentage with the trait = number of individuals with the trait / total population size x 100

(percentage with the trait is equal to number of individuals divided by the total population size times 100)

In this equation, the total population size is the total number of individuals in the population.

Average Population

Individuals in a population may have different values of a trait, such as height. You can use an average, or mean, to represent a typical value of a trait in a population. The following equation shows how to calculate the average from a group of measurements.

average = sum of measurements / number of measurements

(average is equal to the sum of measurements divided by the number of measurements)

You can find the number of measurements by counting the measurements from the group.

You can find the sum of measurements by adding up all of the measurements from the group.

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