Tiktaalik

advertisement
Tiktaalik
Fossil dated to 385359 million years ago
Tiktaalik
Discovered in 2004 on Ellesmere
Island, Canada.
1
Archaeopteryx
Fossil dated to
150 Million years
ago
2
Nostrils
Source: evolution.berkeley.edu
3
“Fossil” beta globin
Scientists have discovered that
The Antarctic Ice Fish
(Chaenocephalus aceratus) does
not have any red blood cells.
Instead of transporting oxygen
through their blood, they absorb
oxygen from the water through
their skin and large gills.
Looks like a broken down beta globin gene
Ice fish genome
It is discovered that the ice fish genome contains a segment that looks like the beta
globin gene found in closely-related fish, but is not functional.
Human chromosome 2
Human chromosome 2
Looks like a centromere
centromeres
Chimp chromosomes 2q and 2p
Humans have 23 pairs of chromosomes. All other ape species have 24 pairs.
6
Vestigial parts
• Humans have much smaller appendices than
herbivorous animals.
• In herbivorous animals, but not in humans, the
appendix serves to aid digestion of plant material.
• It is still unclear what function, if any, the appendix
serves in humans.
• Humans have a small immobile tail made up of four
fused vertebrae.
• In other primates, these vertebrae are not fused
and allow the tail to move, aiding in balance and
mobility.
Guppy experiment #1
Initial observations:
Scientists observe that
male guppies that stand
out from their
surroundings attract more
females
evolution.berkeley.edu
Guppy experiment #2
evolution.berkeley.edu
Staphylococcus aureus
• Bacteria commonly found on mucous membranes
and skin
• Can cause infections (Staph infections)
• Penicillin introduced as antibiotic in 1940
– very effective against Staph in the early 1940’s
• 95% of staph strains now resistant to penicillin
• Many strains are now resistant to multiple
antibiotics: penicillin, methicillin, tetracycline
– MRSA: Methicillin-resistant Staphylococcus aureus
Nested traits
Nucleus
Chloroplast Seeds
Nervous
system
Jaws
Placenta
Feathers
Bacteria
Algae
X
X
Corn
X
X
X
Palm Tree
X
X
X
Jellyfish
X
Starfish
X
X
Human
X
X
X
X
Cow
X
X
X
X
Crocodile
X
X
X
Robin
X
X
X
X
Cardinal
X
X
X
X
Comparing DNA
Species
Partial sequence of beta globin gene
Human
ATGGTGCATCTGACTCCTGAGGAGAAGTCTGCCGTTACTGCCCTGTGG
Macaque
ATGGTGCATCTGACTCCTGAGGAGAAGAATGCCGTCACCACCCTGTGG
Mouse
ATGGTGCACCTGACTGATGCTGAGAAGGCTGCTGTCTCTGGCCTGTGG
Rat
ATGGTGCACCTGACTGATGCTGAGAAGGCTGCTGTTAATGGCCTGTGG
Dog
ATGGTGCATCTGACTGCTGAAGAGAAGAGTCTTATCTCCAGCATGTGG
Download