Evolution Overview

Theory of Evolution – living things evolve in response to change in the environment.

Plate Tectonic Theory – movement of oceanic/continental crust shapes the Earth

Law of Superposition – layers of Earth determine age.

Evolution Overview We will start by stating that there are 3

types of evolution:

1. Geologic – how the Earth has changed

2. Biologic – how life has changed

3. Technologic – how technology has changed

Our Objectives today: 5.01 Interpret ways in which rocks, fossils, and ice

cores record Earth’s geologic history and the evolution of life including: Geologic Time Scale Index Fossils Law of Superposition Unconformity Evidence of Climatic Change Extinction of Species Catastrophic events

Geologic Evolution Rocks, Fossils, and ice cores show:

That life forms have changed over time. Earth’s climate & surface have changed over

time.

Fossils provide important evidence of how life and environmental conditions have changed.

Geologic Evolution Thousands of layers of sedimentary rock

confirm the long history of the changing surface and changing life forms.

Fossils that can be used to help determine the relative age of rock layers are called index fossils.

Geologic Evolution The Law of Superposition states that each

undisturbed rock layer is older than the layer above it.

Relative Geologic Dating – is the estimated age of a rock layer in relation to the layers above and below it.

Youngest layers are not always found on top, because of folding, breaking, and uplift of layers.

Geologic Evolution Absolute geologic dating – uses the decay

of certain elements to determine the exact age of a fossil or rock layer.

Geologic Evolution

By studying rocks & fossils, scientists have developed a geologic time scale which outlines the major divisions of Earth’s history.

Geologic Evolution - Climate Global patterns of atmospheric movement

influence local weather. Oceans have a major effect on climate,

because water in the oceans holds a large amount of heat.

Geologic Evolution - Climate Many factors, natural & anthropogenic (human –

made) determine Earth’s climate. The natural factors can include, but are not limited

to the following: Atmosphere - sun, orbit, tilt, clouds, wind, etc. Geosphere – geography, surface, Earth’s core heat, etc. Hydrosphere – currents, ice, cycles, etc. Biosphere – living organisms, evapotranspiration, surface

runoff, etc.

Geologic Evolution - Climate Human factors also influence regional and

global effects in climate: Land uses – slash and field burning,

deforestation, agriculture, cities. Resource uses – burning of fossil fuels (oil,

wood, and coal)

Biological Evolution Biological evolution accounts for the

diversity of species developed through gradual processes over generations.

Species acquire many of their unique characteristics through biological adaption, which involves the selection of naturally occurring variations.

Biological Evolution Throughout history species that could not

adapt to Earth events died out. (a.k.a. extinction)

Catastrophic events: Asteroids hitting Earth Ice Ages Volcanic Eruptions

Biological Evolution The earliest evidence of life is found in the

oceans, such as deep ocean organisms that rely on chemical energy.

The evolution of Earth’s living things is strongly linked to the movements of the lithospheric plates. Living things evolve in response to their environment.

Biological Evolution Movements of plates cause change in

climate, in geographic features such as mountains, and types of living things in particular places.

When land masses come together diversity decreases.

When land masses grow apart, diversity increases.

Biological Evolution On large land masses offer more variety to

live in. On small land masses animals must adapt

to what they are given. (less options)

Connections Alfred Wegner used:

Mesosaurus fossils found in Africa & South America. Mountain ranges in Eastern U.S. and Canada match

ranges in Greenland & N.W. Europe Ages & types of rock on one continent match the edges of

other continents. Diamonds in Brazil & W. Africa mines are the same Fossils of same plant spores found in Africa, Asia,

Australia, and Antarctica.

Connections With technological advances and utilization

of tools scientists are able to study the interconnections of biological and geological changes overtime.