Big on Biology No Bone About It 9-12 Science Std: Bio 8e

We have talked about Biodiversity Interspecies Diversity Many different species Increases stability Increases resiliency Supports ecosystem Intraspecies Diversity Many different traits Increases stability Increases resiliency Supports species

We have talked about Natural Selection Differentiation of Survival and Reproduction Based on successful traits If you survive – you can reproduce Your successful traits are passed on to offspring Successful traits carried on

Which leads to Evolution Creation of a New Species Based on traits favored by ecosystem But did you know…… There are different kinds of evolution Microevolution Small Evolution Small changes in single populations Like the shape of a bird’s beak

Which leads to Evolution Creation of a New Species Based on traits favored by ecosystem But did you know…… There are different kinds of evolution Macroevolution Major event Changes multiple populations

We know this has happened There are fossils But what is a fossil?

What is a fossil? Simple definition: Fossils are the preserved evidence of ancient life There are 2 types of fossils: Trace Fossils Body Fossils

What is a fossil? Body Fossil Fossil of the actual body of an organism Body of an organism covered by mud and sand Elements in mud replace organic material Organic become mineral (rock)

What is a fossil? Trace Fossil Traces of the activities of plants and animals Footprints or other tracks are covered by mud Some parts harden into rock Softer parts wash away

We can look at the fossil Record Divided into eras and periods Each Era ended with significant event Lets look at the eras and periods starting with the oldest and working our way up

Archean Era Oldest era on Organizer Oldest fossils found here Mostly bacteria and algae 2.5 Billion to 3.8 billion years ago

Proterozoic Era Next era up Primitive aquatic plants No life found on land 570 Million to 2.5 Billion years ago

Paleozoic Era Divided into 7 periods Major changes in organisms Life starts to come onto the land Era of great forests that made the fossil fuels Pangaea comes together during this time

Cambrian Period 500 to 570 Million Years Lots of animals in sea None of them have a backbone Most look like crabs (trilobites)

Ordovician Period 435 to 500 Million Years First signs of fish Snails start to show

Silurian Period 410 to 435 Million Years First plants on land First animals on land

Devonian Period 360 to 410 Million Years Amphibians start to come on land

Mississippian Period 330 to 360 Million Years Sharks start to be seen Large primitive trees on land

Pennsylvanian Period 290 to 330 Million Years Fern forests Lots of insects First reptiles

Permian Period 240 to 290 Million Years Amphibians grow bigger Reptiles grow bigger First major extinction event

Mesozoic Era Divided into 3 periods Age of Dinosaurs Pangaea starts to break up

Triassic Period 205 to 240 Million Years Lots of Pine Trees Different types of reptiles on land and in sea Sizes of reptiles get bigger

Jurassic Period 138 to 205 Million Years First birds and mammals Lots of dinosaurs Most well known from movies

Cretaceous Period 66 to 138 Million Years First flowering plants Lots of biodiversity End of Dinosaurs 65 million years ago

Cenozoic Era Divided into 2 periods Age of Mammals Long term cooling of Earth More diversity of producers

Tertiary Period 1.6 to 66 Million Years Increased diversity of mammals Rocky Mountains, Alps and Himalayas formed Apes got bigger

Quaternary Period 1.6 Million Years to present day The age of man Coming out of major ice age Humans from hominids

Questions?