Camouflage and Natural Selection

Purpose: To understand how the process of natural selection can lead to the rise of new traits among various organisms.

But first…Thumbs!

Prompt:

“Imagine you no longer have either of your opposable thumbs. How would the activities you perform throughout the remainder of the day change for you? What kind of struggles will you now face? What are some abilities you will no longer be able to perform?”

Introducing… Key terms!

• Evolution: changes in the heritable traits of a population of organisms as successive generations replace one another. It is populations of organisms that evolve, not individual organisms!

• Natural Selection: the process by which organisms having traits that better enable them to adapt to specific environmental pressures, will tend to survive and reproduce in greater numbers than others of their kind, thus ensuring the perpetuation of those favorable traits in succeeding generations. (A type of driving force).

Key Terms Continued…

• Adaptation: the alteration or adjustment in structure or habits, often occurring through natural selection, by which a species or individual becomes better able to function in its environment.

• Heredity: the means by which an offspring acquires the genetic information of its parents. Genetics is the science that studies heredity.

What you may already know:

• Dominant and Recessive Traits• Inheritance• Genotype and Phenotype• Evolution occurs in all types of organisms• Some or all of Darwin’s 5 Laws -Common Ancestor, Gradual Change, Natural Selection, etc. • Honorable Mentions: Gregory Mendel and Charles Darwin.

Do you really know it? True or False: Dominant Traits are the traits that are always expressed.

FALSE! Recessive traits are also expressed such as; red hair, attached earlobes, smooth chin, and lack of dimples.

True or False:

Humans evolved from chimpanzees.

FALSE! Humans and chimpanzees share a common ancestor that lived between 5-8million years ago!

True or False:

Adaptations arise to meet the needs of the organism in a changing environment.

FALSE! Adaptations are the result of evolution. Evolution occurs across a species over a long period of time.

True or False:

Acquired physical characteristics can be inherited.

FALSE! Do you think you can inherit a sun tan? Hair length? Missing tooth? Etc.

Adaptations over many years..

• Physical and Behavioral• P- wings, webbed feet,

sharp claws, loose skin, scales, and fur.

• B- what an animal eats, protection, and how an animal moves or does something.

Our adaptation of interest: Camouflage!

• Believed to originate from natural selection! - Reproductive advantage when more offspring survive.- Both predators and prey

• How do offspring survive? -Hiding and better suited to hunt

A parent can leave offspring hidden to seek out food

Camouflage examples all around us!

Camouflage comes in different types!

• Camouflage has evolved in many different species across the world. (Variation).

• The different uses for camouflage lead to different types.

• Let’s take a look at the 4 different types on the next slide!

The Four Types Of Camouflage Are: • Concealing Camouflage- the organism blends into its

surroundings.

• Disruptive Camouflage- the organism(s) look like one mass/object.

• Disguise Camouflage- the organism appears as a leaf, stone, or stick.

• Mimicry Camouflage- the organism looks like another organism that is often dangerous or toxic to ingest.

Concealing Camouflage

Disruptive Camouflage

Disguise Camouflage

Mimicry Camouflage

Practice Time!

Practice!

Practice!

Practice!

In Conclusion:

• Natural Selection leads to evolution over time

• Natural selection operates on favorable traits commonly

• An adaptation does NOT arise to benefit the individual organism

• Sometimes the cause of an adaptation can be a random genetic mutation.

Time to pair up and THINK!

• Work together to complete the “Camouflage Examples Worksheet”.

• Try to come up with different examples than the ones used in the slides.

• Evidence and reasoning are important! - why does this particular type exist for the example you chose?- JUSTIFY

THANK YOU!!!