Evolution of Landforms and Organisms

Extinct: The process through which a species disappears completely from Earth. Not one more of that species is alive.

What might cause an organism to become extinct? An increase or decrease in temperature An increase or decrease in rainfall An earthquake A volcanic eruption Flooding or drought Shifting land or sea A change in food supply A new predator or disease “Natural Causes”

Extinction, can be a natural part of the changes that take place on the Earth. We call the changes that take place over time Normally species survive for 2 to 10 million years “ Evolution” Evolution is the process of change over time.

How do we know, that some organisms that have existed before on the Earth have become extinct? Fossils

Can you name an organism that has lived before on the Earth and is now extinct? Dinosaurs

Mass Extinction This occurs when large numbers of species die out in a fairly short period of time. They have occurred many times - 50 % of all life dies one mass extinction occurred 65 million years ago - DINOSAURS

Human or Natural Causes ? Quagga-last one 1870’s

Natural Causes can be related to Climate Change Species that exist only in a small area could be easily wiped out by a local natural disaster, such as a flood or a volcanic eruption Species that eat only one type of food could disappear quickly if their food source suddenly disappeared

Ice Age - example of climate change 1/3 of Earth was covered with ice 11 different ice ages – last one 25,000 years ago Woolly Mammoth Wooly Rhinos Cave bears

Catastrophic Event A large number of living organisms die

Human Threats to Extinction Habitat Destruction Invaders Pollution Overgrazing, overlogging, forest burning Over harvesting Climate change Poaching, overhunting, overfishing “Global Impact”

Scientists estimate 99.9% of all species that have ever lived on Earth have become extinct. Passenger pigeon Passenger Pigeon Dodo Bird Tasmanian Wolf Scientists estimate 99.9% of all species that have ever lived on Earth have become extinct.

What caused the dinosaurs to become extinct ?

Asteroid Theory An asteroid is a large piece of rock hurling through space Climate Change occurred when it hit Material thrown into atmosphere and blocked out the sun – Earth cooled! Photosynthesis stopped! Plants died - Animals died

Evidence of this asteroid theory is found in the K/T layer of rock. This rock contains an abundance of the element “iridium”

Gradual Theory Some scientists believe that the movement of tectonic plates and increase in volcanic activity on Earth caused global climate change. As volcanoes erupted, thick clouds of dust and soot entered the atmosphere, Blocked out sun Cooled Earth Plants died Animals died

Why are we concerned when an organism becomes extinct?

Evolution BiologicalGeological Technological Charles DarwinAlfred Wegener Societal and Business Needs Finches – birds Galapagos Islands Continental Drift Plate Tectonics Computers Photocopiers Natural Selection AsthenosphereInternet AdaptationBoundariesBusiness - efficient

Biological Evolution Charles Darwin proposed that over time new species developed from old species. He proposed the “Theory of Natural Selection?

Finches

Natural Selection Darwin observed that the shapes of the beaks varied according to the type of food the finches ate. This theory explains how populations evolve (change) into new species over TIME

Natural Selection “Survival of the Fittest” Natural selection refers to reproduction as a function of traits that have a genetic basis Preservation of a species is the natural struggle for life." [1] [1] A natural part of evolution Only the fittest organisms will prevail – not the weak, injured, sick

Adaptations A trait that improves an organism’s chance for survival and reproduction

Memory Trick ABCDEF AdaptationAdaptation BiologIcalBiologIcal FinchesFinches EvolotionEvolotion DarwinDarwin CharlesCharles

Geological Evolution Alfred Wegener A German scientist who observed that the continents appeared to fit together. He proposed that all the continents had once been a single landmass called Pangaea. He suggested they gradually split apart and continents moved to their present positions.

Continental Drift

Geological Evolutio n Continental Drift

Distribution of Living Things Mesosaurus: lizard, reptile South America Africa Continents Were Once Connected

Continental Drift -vs- Plate Tectonics The theory of Continental Drift could not explain how the continents move. So, the Theory of Plate Tectonics was proposed and it showed that the continents were part of larger plates that appeared to move and change over time

Geological Evolution Plate Tectonics Physical Evidence The Theory of Plate Tectonics states that Earth’s lithosphere, or land, is broken into large sections called tectonic plates that move and change over time. Plate Tectonics explains how the continents float on a dense, molten material known as asthenosphere. The rock of the asthenosphere is partially melted, which allows it to flow slowly. Lithosphere – land part of the Earth Asthenosphere

Interior of the Earth Astheonosphere

The continents floated on a dense, molten material called the Asthenosphere (demonstration )

Fault - A crack in the Earth’s crust where movement has occurred.

V olcanoes Earthquakes Lava - molten (melted) material that flows out of a volcano onto the surface of the Earth Magma – molten material below the surface of the Earth Earthquakes occur along faults in the Earth

ConvergentDivergentTransform Plate Boundaries

Convergent Boundary Oceanic and Continental Plate Volcanoes are formed

Divergent Boundaries Sea-Floor Spreading

Technological Evolution Society Needs Technology Business Needs ComputersPersonal Computers Communication Devices Automotive Industry Communication Devices – Fax Internet Medical Field Photography Military Technology GPS – Satellites Entertainment Video Movies Video Games Technology has made businesses more efficient

Question 1 What is the relationship between geological and biological evolutionary theories? a.they both explain history b.they both provide evidence of change on Earth c.they both do not agree on evolution d.they both do not give specific instances of changes Answer : b- provide evidence of change

Question 2 A scientist finds fossils from the same organism in both India and Africa. What is a possible explanation for this occurrence? a.Adaptation b.Continental drift c.Climate change d.Plate tectonics Answer: b - Continental Drift

Question 3 What forces can cause technological evolution? a.Societal forces b.Natural forces c.Physical forces d.Geological forces Answer: a - Societal forces

Question 4 What kind of plate boundaries occurs when the plates are pulling apart? a.Convergent b.Transform c.Fault d.Divergent Answer: d - divergent

Question 5 What kind of geological feature is formed when an oceanic plate converges with a continental plate? a.Chains of volcanic mountains b.Chains of undersea volcanoes c.High continental mountains d.Flat plains Answer: a- chains of volcanic mountains

Question 6 Which theory explains the way populations can change over time? a.Adaptation b.Natural Selection c.Genetics d.Continental Drift Answer: a - Natural Selection

Question 7 What is the main cause of the natural extinction of species? a.Plate tectonics b.Diseases and predators c.Environmental change d.Habitat destruction Answer: c - Environmental change

The End