Transcript Evolution process by which species change over time

Evolution
process by which species change
over time
Adaptation
trait that helps an organism
survive in its environment
More Adaptations
Mutation
Change in a gene, may contribute
to adaptation and evolution
Genes are part of chromosomes which are part
of DNA, which is responsible for your physical
characteristics, inherited through your parents.
What are fossils?
Remains or traces of a once living
organism
• Extinct – no longer
found as a living
species
• Amber – hardened
tree sap
Most fossils are found in
sedimentary rocks, which are
made of layers of sediments
Two Types of Fossils found in
rock
• Molds or Body Fossils
• Formed when an
organism is buried by
sediments and the
sediments change into
rock
• Inside organism
decomposes
• Casts or Trace Fossils
• Formed from an
impression made from
an organism that dried
and turned to rock
(video clip)
Evidence that supports Evolution
• Fossil record shows that changes have
taken place
• Fossil record show marine life on
mountains, which indicate mountains
were once submerged
• Fossils show climate change, fern found
in Antarctica, showing once was warm
• Fossils show extinct organisms
Fossils show similar body
structure
• Homologous
Structures – body
parts that have the
same basic structure
• Vestigial Structures
body parts that
seem to have not
function
Evolution of horses
DNA Evidence of Evolution
• DNA is an organisms genetic material that is
responsible for its characteristics and traits
• Scientists have found common DNA sequencing or
DNA strands in many species indicating they came
from a common ancestor
• Humans and Chimps have 99% similar DNA, alike in
genetic make up
• DNA strands can be extracted from fossils
DNA Evidence
• Electrophoresis –
separates the
DNA strands,
used for evidence
in crimes and
paternity proof.