Grade 8 Physical Science SOL Review Packet Notes

• Two Kinds of Energy

  • Potential Energy: Stored energy that has the capacity to do work but is not currently doing so. Examples include a stretched rubber band, water behind a dam, or chemical energy in fossil fuels.

  • Kinetic Energy: Energy in motion. It is the energy of an object due to its movement. Examples include a moving car, flowing water, or wind.

• Renewable Resources: Resources that can be replenished over a relatively short period, such as solar, wind, and hydroelectric power.

• Nonrenewable Resources: Resources that cannot be easily replenished because they take millions of years to form. Examples include fossil fuels like coal, oil, and natural gas.

• Advantages of Renewable Energy

  • Sustainable: Can be used indefinitely without depleting the resource.

  • Produces little waste products: Minimal pollution compared to nonrenewable resources.

  • Clean air resource: Contributes to better air quality.

• Disadvantages of Renewable Energy

  • Generates less electricity than nonrenewable sources: Lower energy output compared to fossil fuels (challenging but improving daily).

  • Relies on weather conditions: Intermittent sources dependent on sunlight, wind, or water flow.

  • Renewable energy technology is more expensive than traditional forms: Initial costs may be higher, but long-term costs are generally lower due to reduced fuel expenses.

• Advantages of Nonrenewable Energy

  • Readily available and cheap in some areas: Existing infrastructure and established markets make them accessible.

  • Large amounts of electricity can be generated from fossil fuels: High energy density makes high electrical output possible.

• Disadvantages of Nonrenewable Energy

  • Will eventually run out: Finite resources that will be depleted over time.

  • Produces photochemical pollution and greenhouse gases: Contributes to air pollution and climate change.

• Fossil fuels like coal, oil, and natural gas are limited and will eventually be depleted. These fuels are formed from the remains of ancient plants and animals.

• Chemical energy in fossil fuels is stored as potential energy and released as electrical energy through combustion.

• Energy Transformations: Chemical (potential) energy is released as electrical energy, typically through combustion to produce heat, which turns turbines connected to generators.

Earth’s Energy Budget

• Most energy in Earth’s atmosphere is solar energy, traveling as electromagnetic waves. Solar energy is crucial for driving weather patterns, ocean currents, and biological processes.

• Energy reaching Earth is mainly visible light, infrared radiation, and ultraviolet radiation. The composition of solar radiation affects the planet's temperature and living organisms.

• Visible light: ROYGBIV (Red, Orange, Yellow, Green, Blue, Indigo, Violet): the range of electromagnetic radiation that the human eye can detect.

• Infrared radiation: Wavelengths longer than red light: transfers heat.

• Ultraviolet radiation: Wavelengths shorter than violet light: Can be harmful to living tissue but is mostly absorbed by the ozone layer.

• Clouds, dust, and gas particles reflect solar energy back to space, influencing Earth’s albedo and temperature regulation.

• Energy is absorbed by land and water and changed into heat, driving processes like evaporation and convection.

• About 1/3 of incoming solar energy is reflected back to space, known as Earth's albedo.

• About 1/2 of the energy striking Earth is absorbed by Earth’s surface, warming the land and oceans.

• Convection: Rising of warm air and sinking of cool air: plays a vital role in heat distribution.

• Greenhouse Effect: Gases trap heat in the atmosphere, keeping the Earth at a suitable temperature for organisms. Key greenhouse gases include carbon dioxide, methane, and water vapor.

Cloud Formation

• Warm air rises, cools, and water vapor condenses, leading to cloud formation. Rising air expands and cools due to decreasing pressure.

• Water droplets form and attach to dust particles to form clouds; these particles act as condensation nuclei.

Storms

• Thunderstorms form within cumulonimbus clouds and include heavy rain, thunder, and lightning; these storms can be associated with strong winds and hail.

• Hurricanes begin over warm water as low-pressure areas with high winds and heavy rains, mostly in the Atlantic Ocean north of the equator. The warm water provides the energy for the storm.

• Tropical disturbance → Tropical storm → Hurricane (Ocean temperatures of 82°F or warmer). The Saffir-Simpson Hurricane Wind Scale is used to classify hurricanes based on wind speed.

Matter

• Matter has mass and takes up space (volume). It exists in various states, including solid, liquid, gas, and plasma.

• Mass: Amount of matter in an object (SI unit: kilogram). Mass is a measure of inertia.

• Volume: Amount of space matter occupies (units: cm3, liter, mL). Volume can be determined through displacement or calculation.

• Matter is made of smaller particles called elements, which are the basic building blocks of matter.

• Elements: Made of one kind of atom that cannot be broken down by chemical or physical means. Elements are organized in the periodic table.

• Atoms: Smallest units of an element with the properties of that element. Atoms consist of protons, neutrons, and electrons.

• Atoms are made of subatomic particles: protons (positive charge), neutrons (no charge), and electrons (negative charge).

• John Dalton’s Atomic Theory:

  • Atoms can’t be broken into smaller pieces; atoms are indivisible in chemical reactions.

  • Atoms of the same element are exactly alike; all atoms of a given element have the same properties.

  • Atoms of different elements are different; they have different masses and properties.

  • Atoms of two or more elements can combine to form compounds; chemical reactions involve the rearrangement of atoms.

  • Atoms of each element have a unique mass; the atomic mass is a characteristic property.

  • The masses of elements in a compound are always in a constant ratio; this is the law of definite proportions.

Elements

• Chemical symbols are abbreviations for elements (one or two letters, first letter capitalized). These symbols are universally recognized.

• Common elements in Earth’s crust, living matter, oceans, and atmosphere: Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N), Silicon (Si), Aluminum (Al), Iron (Fe), Sodium (Na), Calcium (Ca), Potassium (K), Magnesium (Mg).

Compounds

• Chemical formulas use symbols to represent atoms in a compound; these formulas indicate the types and numbers of atoms.

• Formulas show elements present and their ratios. For example, H_2O has two hydrogen atoms and one oxygen atom.

• Compounds: Pure substances made of two or more chemically combined elements in fixed mass ratios joined by chemical bonds. Chemical bonds include ionic, covalent, and metallic bonds.

• Properties of compounds differ from those of their constituent elements; for example, water (H2O) has different properties than hydrogen and oxygen gases.

• Chemical Equation: Represents a chemical reaction with reactants on the left and products on the right, separated by an arrow (yield symbol). Equations must be balanced to conserve mass.

• Coefficients indicate the number of molecules; subscripts indicate the number of atoms of an element in a molecule. Balancing equations ensures the number of atoms is the same on both sides of the equation.

Properties and Characteristics of Water

• A mixture is a material composed of two or more elements or compounds physically mixed together. Mixtures can be homogeneous or heterogeneous.

• A solution is a mixture of two or more substances in which the molecules of the substances are evenly distributed.

  • Solute – the substance that is dissolved (smallest amount)

  • Solvent – the substance in which the solute dissolves (largest amount)

• Suspension is a mixture of water and undissolved materials; these materials are visible and will settle over time.

• Water is known as a universal solvent because it dissolves most things due to its polar nature.

• Polar Molecule: A molecule that has electrically charged areas giving it the ability to break up substances into smaller pieces to dissolve them.

• Surface Tension: The tightness across the surface of water that is caused by the polar molecules pulling on one another making the surface act like a solid. Surface tension allows small insects to walk on water.

• Cohesion: the attractive force between water molecules, causing them to stick together.

• Adhesion: occurs when molecules of water are attracted to other substances, such as the walls of a glass tube.

• Capillary action is the combined force of attraction among water molecules and with the molecules of the surrounding material (Cohesion + Adhesion). Capillary action is essential for water transport in plants.

• Specific Heat: Water has a really HIGH specific heat which means it takes a lot of energy for water to increase its temperature. This property helps moderate temperatures in aquatic environments.

• Ice floats due to its density and triangular molecular structure combined with it’s lower density, insulating bodies of water and supporting aquatic life during freezing conditions.

Weathering

• Physical Weathering: Rocks are broken into smaller pieces without changing their chemical composition.

  • Examples: freezing and thawing, ice/frost wedging, release of pressure, growth of plants, actions of animals, and abrasion

• Chemical Weathering: Breaks down rocks through chemical changes.

  • Caused by: water, oxygen, carbon dioxide, organisms, and acid rain

Absorption of Thermal Energy

• Water absorbs heat energy without showing large temperature changes, moderating the climate of nearby areas. This is due to water's high specific heat capacity.

Irrigation and Power Generation

• Water is essential for agriculture, increasing crop productivity. Irrigation systems provide water to crops in areas with limited rainfall.

• Hydroelectric power plants use the kinetic energy of water flow, converting it into electricity using turbines and generators.

• Water is heated and turned to steam in power plants to turn turbines that generate electricity; power plants use both fossil fuels and nuclear energy to heat water.

Clean Water and Health

• Most of Earth’s water is salt water (97%). Salt water is found in oceans and seas.

• Non-frozen, fresh water makes up less than 1% of the water on Earth. Fresh water is essential for drinking, agriculture, and industry.

• Advances in water treatment and sanitary sewers have helped eliminate diseases associated with human waste, improving public health.

• Water conservation means using less water or recycling used water. Conservation practices help ensure sustainable water resources.

Earth’s Atmosphere

• Air is a mixture of gaseous elements and compounds, including nitrogen, oxygen, water, argon, and carbon dioxide. These gases are essential for life and climate regulation.

• Nitrogen makes up the largest proportion of air (78%). Nitrogen is relatively inert and dilutes oxygen.

• Atmosphere Composition: 78% Nitrogen, 21% Oxygen, 1% Other (argon, carbon dioxide, hydrogen, methane, etc.)

• Air has mass and density D = \frac{M}{V}. Density varies with temperature and pressure.

• Air pressure is the result of the weight of a column of air pushing down on an area. Pressure is measured using a barometer.

• Air pressure decreases as altitude increases due to the decreasing weight of the air above.

• Humidity is the amount of water vapor in the atmosphere. Humidity influences precipitation and weather patterns.

• Absolute humidity is the amount of water vapor divided by the amount of dry air. Measured in grams of water per kilogram of dry air.

• Relative humidity is the ratio of current absolute humidity to the highest possible absolute humidity; expressed as a percentage.

Layers of the Atmosphere

• Troposphere: Closest to Earth’s surface; life and weather occur here; contains 99% of the water vapor. The troposphere is heated from the ground up.

• Stratosphere: Above the troposphere; contains the ozone layer, which absorbs harmful UV radiation.

• Mesosphere: Above the stratosphere; temperature decreases with altitude; most meteors burn up here due to friction with air molecules.

• Thermosphere: Above the mesosphere; temperature can soar due to solar activity; contains the ionosphere, which reflects radio waves.

• Exosphere: Outermost layer, merging with outer space; hydrogen and helium are the main gases. The exosphere is very thin and has no clear upper boundary.

Changes to the Atmosphere

• Human activities have increased greenhouse gases (carbon dioxide and methane), trapping more heat and leading to global warming. Deforestation, burning fossil fuels, and industrial processes contribute to increased greenhouse gas concentrations.

• Ozone layer depletion due to chlorofluorocarbons (CFCs); this depletion allows more harmful UV radiation to reach the surface. CFCs were used in refrigerants and aerosols.

• Air pollution from fossil fuel combustion leading to smog and acid rain. Pollutants include sulfur dioxide, nitrogen oxides, and particulate matter.

Clouds

• Cirrus: Wispy, curly clouds high in the atmosphere; made of ice crystals.

• Stratus: Sheet-like layers that cover the sky; can produce drizzle or light snow.

• Cumulus: Heaped or piled clouds; associated with fair weather but can develop into thunderstorms.

Weather

• Air Mass Types: Continental (c), Maritime (m), Tropical (T), Polar (P)

  • Continental polar (cP): Cold and Dry; forms over land at high latitudes.

  • Continental tropical (cT): Hot and dry; forms over land at low latitudes.

  • Maritime polar (mP): Cold and humid (winter), Cool and humid (summer); forms over oceans at high latitudes.

  • Maritime tropical (mT): Warm and humid; forms over oceans at low latitudes.

• Weather Front: Where two air masses meet with different temperatures and densities collide, but do not mix. Fronts are associated with changes in weather conditions.

• Weather Related Phenomena

  • Thunderstorm: Includes lightning and is produced by a cumulonimbus cloud, heavy, rain, gusty winds and sometimes hail. Thunderstorms form due to atmospheric instability.

  • Tornado: A violent rotating column of air extending from a thunderstorm to the ground. Most tornadoes form from supercell thunderstorms.

  • Hurricane: Huge storm with strong winds spiraling inward, can be up to 600 miles across, sustained winds above 74 mph lasting for over a week. Hurricanes only form over really warm ocean water; they dissipate over land or cooler water.

Living Systems

• Ecosystem: Biotic community and abiotic factors that affect it

  • Biotic: Living things such as animals, plants, fungi, and bacteria. Biotic factors interact in complex ways within an ecosystem.

  • Abiotic: Nonliving things such as water supply, topography, landforms, geology, soils, sunlight, and air. Abiotic factors influence the distribution and abundance of organisms.

Watershed Systems

• Watershed: Land that water flows across or through on its way to a body of water. Areas of higher elevations like ridgelines separate watersheds. Watersheds are essential for water supply and flood control.

• Virginia’s Watershed Systems: Chesapeake Bay, North Carolina sounds, or the Gulf of Mexico. These systems support diverse ecosystems and human activities.

• Wetlands: Transition zone between dry land and bodies of water; regulate water flow, reduce erosion, maintain water quality, recharge groundwater, and provide habitat for wildlife. Wetlands act as natural sponges, absorbing excess water.

• Estuaries: Bodies of water where rivers meet the sea; provide habitat and serve as nurseries for marine life. Estuaries are highly productive ecosystems.

• Chesapeake Bay: Largest estuary in the contiguous United States. Water quality and salinity needs to be maintained for it to thrive. Pollution and nutrient runoff threaten the health of the Chesapeake Bay.

• Water quality monitoring is collection of water samples to analyze chemical and/or biological parameters; this helps assess the health of aquatic ecosystems.

Our Solar System

• Solar System Includes: the sun, moon, Earth, other planets and their moons, meteors, asteroids, and comets. These objects are held together by gravity.

• Sun: Source of all life on Earth; produces heat and light and its strong gravity holds the planets in their orbits.

  • Features: sunspots and solar flares, prominences (reddish loops of gas). These features are caused by magnetic activity.

• Moons: Natural satellites that revolve around planets. Moons vary in size and composition.

• Meteoroid: Object orbits out in space; a small rock or particle.

• Meteor: Object that burns up and enters Earth’s atmosphere, creating a streak of light.

• Meteorite: Fragments from space that survive and land on Earth; can leave craters on Earth indicating where they once traveled.

• Comets: Large bodies of ice, gas, rock, and dust that travel around the sun; known as “dirty snowballs”. Comets have highly elliptical orbits.

• Asteroids: Pieces of rock made of minerals and metals; Asteroid belt exists between Mars and Jupiter. The asteroid belt is a region of numerous asteroids.

• Inner Planets: Mercury, Venus, Earth, and Mars (small, dense, rocky). Also known as terrestrial planets.

• Outer Planets: Jupiter, Saturn, Uranus, Neptune (largest, composed of gases and liquids). Also known as gas giants.

• Dwarf Planet: Object the size of a planet but that is not a planet or moon; examples include Pluto and Ceres.

• Astronomical Unit (AU): 150 million kilometers, the average distance from Earth to the sun. Used to measure distances within the solar system.

• Gravity is the force pulling together all matter, proportional to mass and inversely proportional to the square of the distance.

The Moon, Eclipses, and Tides

• Moon completes phases in about one month (27.3 days). The phases are caused by the changing angles at which we view the moon's illuminated surface.

• Lunar Eclipse: Earth is between the sun and the moon, casting a shadow on the moon. Can only occur during a full moon.

• Solar Eclipse: Moon is between the Earth and the sun, blocking the sun’s light. Can only occur during a new moon.

• Tides: Periodic rising and falling of bodies of water due to gravitational pull between Earth and moon. High and low tides occur approximately twice a day.

Development of Solar System Understanding

• Ptolemy: Thought Earth was at the center of the Solar System (Geocentric). His model was widely accepted for centuries.

• Aristotle: Believed the universe was finite and the Earth was at its center. His views influenced scientific thought for many years.

• Copernicus: Believed the sun is at the center of the Solar System (heliocentric). His theory revolutionized astronomy.

• Galileo: Used telescope to gather evidence to support Copernicus’ heliocentric model. His observations included the phases of Venus and the moons of Jupiter.

Cells

• History Summary 1665-1855 Includes: Robert Hooke, Anton van Leeuwenhoek, Robert Brown, Matthias Jakob Schleiden, Theodor Schwann, Albrecht von Roelliker, Carl Heinrich Braun & Rudolf Virchow, all major contributors to modern cell theory.

• Cell Theory

  • All living organisms are composed of cells. Cells are the fundamental units of life.

  • Cells are the smallest unit (structure) of living things that can perform the processes (functions) necessary for life. Cells carry out all life processes.

  • Living cells come only from other living cells through cell division.

Cell Structures (Functions)

• Cell Wall: Protect & support cell; provides rigidity and shape, found in plant, bacteria, and fungi cells.

• Cell Membrane: Controls movement of materials into and out of the cell & site of photosynthesis (in bacteria and plant cells); selectively permeable.

• Mitochondria: Breaks down sugar molecules through cellular respiration to produce ATP (energy); powerhouse of the cell.

• Endoplasmic Reticulum: Carries materials through the cell; network of membranes involved in protein and lipid synthesis.

• Chloroplasts: Uses energy from the sun to make food for the plant through photosynthesis; contains chlorophyll.

• Vacuoles: Store food, water and waste; large central vacuole in plant cells stores water and helps maintain turgor pressure.

• Nucleus: Controls cells’ activities; contains DNA and is the control center of the cell.

• Cytoplasm: Contains all organelles and cell parts (jelly-like fluid); site of many chemical reactions.

The Cell Cycle: Growth and Division Process

• Interphase: Time between cell divisions that include Growth, DNA replication & Preparation for division. The cell spends most of its life cycle in interphase.

• Mitosis: Produces two identical daughter cells (PMAT)

  • Prophase: Chromosomes coil, nucleolus disappears, nuclear membrane disappears & spindle forms. The nuclear envelope breaks down.

  • Metaphase: Chromosomes line up at the center of the cell (called the metaphase plate). Spindle fibers attach to centromeres.

  • Anaphase: Centromeres split & chromatids are pulled to opposite poles of the cell. Sister chromatids separate.

  • Telophase: Chromosomes uncoil & nuclear membrane reappears. Two new nuclei form.

• Cytokinesis: Division of the cytoplasm, resulting in two separate daughter cells.

• Meiosis: Is the production of sperm and egg cells through two rounds of division, resulting in four genetically different haploid cells.

Cellular Organization

• Unicellular organisms are made up of one cell (prokaryotes) such as bacteria and archaea.

• Multicellular organisms are made of more than one cell; cells are specialized to perform specific functions.

Life Processes & Body Systems

Life Process and their associated Organ Systems

• Ingestion: Intake of food from various sources in the environment (Digestive System)

• Digestion: Converts complex food substances to simpler ones (Digestive System)

• Removal of waste: The body rids itself of products which are not needed (Excretory System)

• Stimulus response: A condition (stimulus) which causes an organism to have a reaction (response) (Nervous System)

• Growth and repair: Humans obtain energy and materials for body repair and growth Cell division is involved in growth, development, and repair
  
  Body Systems work together*

• Gas exchange: We need to get oxygen from the air into the blood, and we need to remove waste carbon dioxide from the blood into the air (Respiratory System).

• Reproduction: Process by which new individual organisms – “offspring” – are produced from their “parents” (Reproductive system)

Classification of Living Things

• Living things are classified today into 3 major domains (Archaea, Bacteria & Eukarya) divided into kingdoms by similar characteristics, starting with a large group with wide varieties of organisms, to more specific groups. This classification reflects evolutionary relationships.

• Carolus Linnaeus organized and classified organisms into groups by similar characteristics, a method called binomial nomenclature. This is the basis for modern Taxonomy. Linnaeus's system provided a consistent way to name and classify organisms.

• Levels of classification (In order). Kingdom, Phylum, Class, Order, Family, Genus, & Species. Each level represents a more specific grouping.

• Levels in the currently accepted hierarchy include domain, kingdom, phylum, class, order, family, genus, and species. This hierarchical system helps understand the diversity of life.

• Remember "Did King Phillip come over for good spaghetti?"

• Binary nomenclature is a formal system of naming organisms using two Latinized names, the genus and the species. The rules must be used or the scientific name will be invalid. The first name is the genus, and the second is the species.

Photosynthesis

When the sun's solar energy is converted to chemical energy, stored in the form of glucose (sugar). Photosynthesis is the foundation of most food chains.

• Photosynthesis occurs in eukaryotic cell structures called chloroplasts that contain a green pigment called chlorophyll. Chlorophyll captures light energy.
  6CO2 + 6H2O \xrightarrow{\text{light}} C6H{12}O6 + 6O2

CARBON, WATER, and NITROGEN CYCLES

• Sunlight, CO_2, Factory & vehicle emissions are used in the Carbon cycle. This cycle is completed with Plant respiration, Animal respiration, & Decay organisms leading to Organic Carbon. The carbon cycle involves the exchange of carbon between the atmosphere, oceans, land, and living organisms.

• The Nitrogen Cycle starts with Atmospheric Nitrogen (N2), Ocean Uptake, & Nitrogen Fixing. This cycle proceeds with Plants, Animals, NitRates (NO3) Denitrifying Bacteria, Nitrate & Denitrates (NH_2+). The nitrogen cycle is essential for plant growth and protein synthesis.

• The Water Cycle is shown in the Transcript PDF. Key parts of the water cycle are Sun, Evaporates, Condenses, & Precipitation. The water cycle involves evaporation, condensation, and precipitation.

Ecosystems

• Biosphere: is the largest most encompassing Ecosystem we have on planet Earth. The biosphere includes all living organisms and their environments.

• Ecosystem: Within in each ecosystem there are (biotic) living populations of plant and animal organisms. Ecosystems can be terrestrial or aquatic.

• Each biotic population also require (abiotic) requirements for their populations to thrive. Abiotic factors influence the distribution and abundance of species.

Food Chain & Web

Organisms are linked through different nutritional patterns:

• Producers: (plants), Herbivores: (Animals that eat plants), Omnivores: (Animals that eat plants and animals), Carnivores: (animals that eat only animals) & Decomposers: (bacteria, worms.)-Decompose any and all dead living things.

• Food Chains is based on inter relations of living things, and transfer of energy, and movement using arrows to show direction of energy thru the food chain. Food chains show the flow of energy from one organism

• Food web is an interconnected food chain and relies on the sun for energy and is the constant supply of energy thru the circle. Food webs represent the complex feeding relationships within an ecosystem.

• An energy pyramid shows that 90% of the energy is lost thru each transfer and energy. An energy pyramid better defines the amount of transfers needed. This loss of energy limits the number of trophic levels in an ecosystem.

Symbiosis

Symbiosis is an exclusive type of system between different species.

• Mutualism symbiotic relationships, in which the species depends and/or benefits equally to each other. Both species benefit in a mutualistic relationship.

• Commensalism relationship is where, at least one organism benefits while the other other does not reap the benefits or does not get harmed. One species benefits, and the other is neither harmed nor helped in a commensal relationship.

• parasitism has to have at least one of the species benefit from the other and where the partner gets adversely affected. One species benefits at the expense of the other in a parasitic relationship.

GENETICS

• In 1953 Dr. James Watson, Francis Crick, and Rosalind Franklin determined the double helix structure of DNA. This discovery revolutionized the field of genetics.
  -DNA contains coded instructions that store and pass on genetic information from one generation to the next. DNA carries the genetic code for all living organisms.

• DNA is found inside a special area of the cell called the nucleus. This packaged form of the DNA is called a chromosome. Chromosomes are made of DNA and proteins.

• DNA is made of chemical building blocks called nucleotides & these building blocks also include sugar, nitrogenous bases, and phosphates. Nucleotides are the building blocks of DNA.

• The four types of nitrogen bases found in nucleotides include: Adenine (A), Thymine (T), Guanine (G), Cytosine (C). These bases pair in a specific manner: A with T, and G with C.

• The order, or sequence, of these bases determines what biological instructions are contained in a strand of DNA and the necessity for DNA to replicate (copy). This allows each resulting cell after mitosis and cell division has the same DNA as the parent cell. DNA replication ensures genetic continuity.

• VARIATION: genotype & phenotype play an important role for our traits. This variation due to genetic recombination, mutations, and environmental influences.

PUNNETT SQUARES

An easy way to map out possibilities in a procreated pattern is through simple mapping. Punnett squares predict genotype and phenotype ratios in offspring.

EVOLUTION

Evolution is driven by Charles Darwin: Natural Selection & can be defined thru Adaptation & Speciation. With influences thru Geography & The Great Pangea Split. Natural selection favors individuals with advantageous traits.

• New species can be made by isolating a sub group from the main organism. Geographic isolation can lead to speciation.

• FOSSILS are remains and/or traces of organisms and are mainly formed under sedimentary rocks.

• Relative Dating can be used