evolution and adaptation

1. Evolution and Adaptation

3. • Evolution = Theory that groups of organisms change
over time
• Occurs over many generations due to selection and
adaptation to changing environments.

4. • Ancient living organisms looked different than the
organisms living today.
• The study of evolution asks: what happened to cause
this shift and how did this process occur?
• Scientists are interested in the relationships between
groups of organisms, and explaining similarities
based on shared ancestry.

5. Phylogeny – Study of the evolutionary history of
organisms.
• Family Tree of related organisms is called a
phylogenetic tree.

6. http://www.onezoom.org/

7. How did scientists build these trees?
What is the evidence of evolution?

8. Fossils
● Fossils are preserved
remains of ancient
organisms or their tracks.
● best evidence of evolution
● formed when plant or animal
matter is changed to stone
or the “imprint” is solidified.
● Fossils found in deeper
layers are older than fossils
found close to the surface

9. ● Fossil record = collection of fossils that show
change within a species over time (history of
organisms)
● Has “gaps” in it so it is said to be incomplete.
(Transition fossils are missing)

10. Tarpits
●
Ancient organisms die and decompose forming fossil
fuels.
●
Over time certain geological conditions have allowed
the fossil fuels to seep up to the surface.
●
Lighter petroleum products evaporate away leaving
behind sticky “tar”
●
Animals became trapped in the tar and died.
●
Rich source of fossil evidence.

11. Amber
●
Hardened gum/ sap of a tree
●
Insects or plant material become trapped and
preserved.

12. Flash Frozen
●
Organism quickly frozen
and preserved during
sudden change in
climate or glaciation
event.

13. Comparative Anatomy
●
Similarity of structures between ancient and modern day
organisms.

14. Embryology
●
In vertebrates, the early stages of development look very
similar with tails and gill slits
●
Suggests similar ancestors – embryology traces
evolutionary pathway

15. DNA
●
DNA has the same chemical make up for every living
thing on Earth
• Scientists compare the genes of different species to
determine how closely related the species are.
• The more similar the sequence of bases in the DNA, the
more closely related the species are.
• The more similar the order of amino acids (codes for
proteins) in the DNA, the more closely related the species
are.

16. Fossilized footprint puzzle
●
attempting to reconstruct happenings from the
geological past by analyzing a set of fossilized
track
●

17. ●
Can you tell anything about the size or nature of
the organisms?
●
Were all the tracks made at the same time?
●
How many animals were involved?
●
Can you reconstruct a series of events represented
by this set of fossil tracks?

18. What can you determine is occurring from
this footprint evidence?

19. ●
In what directions did the animals move?
●
Did they change their speed and direction?
●
What might have changed the footprint pattern?
●
Was the land level or irregular?
●
Was the soil moist or dry on the day these tracks were
made?
●
In what kind of rock were the prints made?
●
Were the sediments coarse or fine where the tracks were
made?
●
What conditions were necessary for their preservation?

20. What can you
interpret what has
happened?

21. ●
One of the most common is that two animals
met and fought. No real reason exists to
assume that one animal attacked and ate the
other.