Download Evidence for Evolution

Evidence for Evolution
by
Natural Selection
Hunting for
evolution clues…
Elementary, my
dear, Darwin!
Regents Biology
2006-2007
Evidence supporting evolution
 __________________________

change over time
 __________________________

comparing body structures
 homology & vestigial structures
 embryology & development
 ______________________

protein & DNA sequence
 ______________________

human caused evolution
Regents Biology
1. Fossil record
 __________________________________

new layers cover older ones
 creates a record over time

___________________________________
___________________________________
 over a long period of time
Regents Biology
Fossils tell a story…
the Earth is old
Life is old
Life on Earth has changed
Regents Biology
Evolution of birds
Today’s organisms
descended from
ancestral species
Fossil of Archaeopteryx
 lived about 150 mya
 links reptiles & birds
Regents Biology
We found the fossil — no joke!
Land Mammal
?
?
?
Complete series
of transitional
fossils
Someone’s idea of a joke!
Regents
ButBiology
the joke’s
on them!!
Ocean Mammal
?
Evolution from sea to land
 2006 fossil discovery of early tetrapod

4 limbs
 Missing link from sea to land animals
Regents Biology
3. Anatomical record
Animals with different
structures on the surface
But when you look under
the skin…
It tells an evolutionary story
of common ancestors
Regents Biology
Compare the bones
 __________________________________

limbs that perform __________________
are built from the ___________________
How could these
very different animals
have the
same bones?
Regents Biology
Homologous structures
 ____________________________________
 homo- = same
 -logous = information
 Forelimbs of human, cats, whales, & bats

______________________________
 on the inside
______________________________
 ______________________________

 on the outside

______________________________
Regents Biology
But don’t be fooled by these…
 _________________________

look similar
 on the outside
same function
 different structure & development

How is a bird
like a bug?
 on the inside
different origin
 __________________________

Solving a similar problem with a similar solution
Regents Biology
Analogous structures
 Dolphins: aquatic mammal
 Fish: aquatic vertebrate
both adapted to
life in the sea
 not closely related

Watch the tail!
Regents Biology
Convergent evolution
 3 groups with wings

Does this mean they have a
recent common ancestor?
They just
came up
with the
sameNO!
answer!
Regents Biology
Flight evolved 3
separate times —
evolving similar
solutions to similar
“problems”
Convergent evolution led to mimicry
 Why do these pairs look so similar?
Monarch male
Viceroy male
poisonous
edible
Which is the moth
vs.
the
bee?
fly vs. the bee?
Regents Biology
fly
bee
moth
bee
Vestigial organs
 Hind leg bones on whale fossils
Why would whales
have pelvis & leg
bones if they were
always sea creatures?
Because they
used to
walk on land!
Regents Biology
Comparative embryology
 Development of embryo tells an
evolutionary story

similar structures during development
all vertebrate embryos have a “gill
pouch” at one stage of development
Regents Biology
3. Molecular record
 Comparing DNA & protein structure

everyone uses the same genetic code!
 DNA
Human
Macaque
Dog Bird
Frog
Lamprey
8
32 45
67
125
 compare common genes
 compare common proteins
number of amino acids different
from human hemoglobin
0 10 20 30 40 50 60 70 80 90 100 110 120
Regents Biology
Building “family” trees
Closely related species are branches on the tree —
coming from a common ancestor
Regents Biology
4. Artificial selection
 How do we know natural selection can
change a population?
we can recreate a similar process
 __________________________________
“descendants” of wild mustard

Regents Biology
Selective Breeding
Humans create the
change over time
Regents Biology
“descendants”
of the wolf
Artificial Selection
…and the
examples
keep coming!
I liked
breeding
pigeons!
Regents Biology
Artificial Selection gone bad!
 Unexpected
consequences of
artificial selection
Antibiotic resistance
Antibiotic resistance
Regents Biology
Insecticide resistance
 Spray the field, but…

____________________
____________________
 _________________
____________________
____________________
 ____________________
 ____________________
____________________

Regents Biology
Regents Biology
Any Questions??
Regents Biology
2006-2007