Evolution StudyGuide

Honors BIO 9th grade

What is evolution?

The change inherited traits of a population over many generations

Who first described the process of evolution?

Charles Darwin

Describe what Darwin observed on his voyage around the world…

• Species variation

• Geographical patterns

• fossil discoveries

• geological changes

Describe evolution by Natural Selection

the process through which populations of living organisms adapt and change over generations

Define fitness

measures an organism's success at surviving, reproducing, and passing its genes to the next generation in a specific environment

Define competition

a fundamental interaction between organisms (same or different species) that vie for the same limited resources in an ecosystem.

What is an adaptation?

the biological process where species develop or inherit traits—structural, functional, or behavioral—that help them survive and reproduce in their environment.

List the 3 types of adaptations and describe how each one helps an organism survive and reproduce in its natural environment.

1. Structural

2. behavioral

3. physiological

What is camouflage?

materials, colors, or patterns to disguise, conceal, or blend an object or organism into its surroundings to deceive or avoid detection

List the 5 types of camouflage and explain each one.

1. Concealing Coloration (Background Matching): An animal matches its body color to the surrounding background

2. Disruptive Coloration: Patterns such as spots or stripes break up an animal’s outline, making it hard to see the body shape

3. Countershading: A form of shading where the top of the body is dark and the bottom is light, canceling out shadows and blending with both the bottom and surface of water (e.g., sharks and penguins).

4. Disguise (Masquerade): The animal takes on the appearance of an inedible object in its environment, such as a twig, leaf, or bird dropping

5. Mimicry: A vulnerable species evolves to look, act, or smell like a more dangerous or bad-tasting species to deceive predators

Define descent with modification.

Charles Darwin’s term for evolution, proposing that species change over time, pass new traits to offspring, and share a common ancestor.

Evidence for Evolution

fossil record, comparative anatomy, molecular biology (DNA), bio geography, and embryology

Define homologous structures and give one example

Definition:physical features or anatomical structures shared by different species that are similar because they were inherited from a common ancestor

EX:Human arm/hand: Used for grasping and lifting.

Define vestigial structure and give one example.

Definition:an anatomical feature, organ, or behavior in a species that has lost most or all of its original ancestral function through the process of evolution

EX:Human Tailbone (Coccyx): A remnant of a tail used for balance in primate ancestors.

What is a gene pool?

the total collection of all unique genes and their alleles present within a specific, interbreeding population at any given time

Name the two main sources of genetic variation amongst organisms.

-mutation

-reproduction

Explain the difference between single-gene traits and polygenic traits.  What are the numbers of phenotypes possible for each trait?

• how many genes control the trait

• 2–3 phenotypes for single-gene traits

Describe the 3 main types of selection that can affect the distribution of phenotypes of polygenic traits.

1. Directional selection

2. Stabilizing selection

3. Disruptive selection

What is speciation and describe how a species evolves into two new species?

the evolutionary process by which a single ancestral species splits into two or more distinct, re productively isolated species

List the 3 types of isolating mechanisms and explain each one.

1. Temporal

2. Behavioral

3. Mechanical

Who are paleontologists?

a scientist who studies the history of life on Earth through fossils

Explain what a fossil is

the preserved remains, impression, or trace of any once-living organism from a past geological age, typically over 10,000 years old

Explain the difference between relative and absolute dating.

Relative Dating(ORDER)- determines the order of events by looking at the position of rock layers, but it does not give an exact age in years

Absolute Dating(AGE)- Uses scientific methods to determine specific numerical age

Explain half life

the time required for a living organism (such as a human) to naturally eliminate, metabolize, or excrete half of the initial amount of a substance—such as a drug, toxin, or radioactive material—from its body or a specific organ.

How old is the Earth?

4.5 billion year old

Describe what taxonomy and taxons are

• Taxonomy is the science of naming, describing, and classifying organisms into ordered groups based on shared characteristics.

• A taxon (plural: taxa) is a specific, named group within that classification system (e.g., Species, Genus, Family, or Kingdom).

Binomial nomenclature

a formal, two-part Latin naming system for species

What does it mean to go extinct

a species of animal or plant has died out completely, with no living representatives remaining on Earth

Short Answer Question: (3 points)  Explain in detail, what evolution by natural selection is and provide an example.  Use at least FOUR of the following words and write THREE or MORE sentences in your explanation.  DARWIN / ORGANISM(S) / TRAITS / SURVIVE / REPRODUCE / ADAPTATION / ADAPT / HABITAT / FITNESS / POPULATION / ENVIRONMENT / COMPETITION / VARIATION

the process proposed by Darwin, wherein organisms with heritable traits better suited to their environment are more likely to survive and reproduce than others