Big on Biology

No Bone About It

9-12 Science Std: Bio 8e

We have talked about BiodiversityInterspecies Diversity

Many different speciesIncreases stabilityIncreases resiliencySupports ecosystem

Intraspecies DiversityMany different traitsIncreases stabilityIncreases resiliencySupports species

We have talked about Natural Selection

Differentiation of Survival and ReproductionBased on successful traitsIf you survive – you can reproduceYour successful traits are passed on to offspringSuccessful traits carried on

Which leads to Evolution

Creation of a New SpeciesBased on traits favored by ecosystem

But did you know……There are different kinds of evolution

MicroevolutionSmall EvolutionSmall changes in single populationsLike the shape of a bird’s beak

Which leads to Evolution

Creation of a New SpeciesBased on traits favored by ecosystem

But did you know……There are different kinds of evolution

MacroevolutionMajor eventChanges multiple populations

We know this has happened

There are fossilsBut what is a fossil?

What is a fossil?

Simple definition:Fossils are the preserved evidence of ancient life

There are 2 types of fossils:

Body Fossils Trace Fossils

What is a fossil?

Body FossilFossil 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 FossilTraces 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

The Fossil RecordDivided 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 Period1.6 Million Years to present day

The age of man

Coming out of major ice age

Humans from hominids

Questions?