paleontology study of prehistoric life
DESCRIPTION
Paleontology Study of prehistoric life. Fossils preserved remains or traces of organisms; evidence of past life. http://evolution.berkeley.edu/evolibrary/article/0_0_0/lines_03. Paleontology. The Fossil Record Fossils and their placement in rock formations and sedimentary strata. - PowerPoint PPT PresentationTRANSCRIPT
EvolutionEvidence of
change
The fossil
record
Similarities in body
structure
Similarities in early
development
Similarities in chemical
composition
Distribution of species
PaleontologyStudy of prehistoric life
Fossils • preserved remains or traces of organisms; • evidence of past life http://evolution.berkeley.edu/evolibrary/article/0_0_0/lines_03
http://www.nap.edu/openbook.php?record_id=6024&page=12
The Fossil RecordFossils and their placement in rock formations and sedimentary strata
Paleontology
How fossils are formed
http://www.wwnorton.com/college/anthro/our-origins2/img/AskClarkFAQs/Figure-8.4.jpg
Paleontology
Geology• Estimate of
fossil’s age in comparison with other fossils
• Layers may not have been deposited horizontally or may have been overturned
Radiochemistry• Age of the
sample is calculated based on the amount of radioactive elements contained
• C14 N14 upon an animal’s death
• C14>C12 = older organisms
• K40 for older samples
http://evolution.berkeley.edu/evosite/lines/IIIAchronology.shtml
Paleontology
Fossils link the present with the past• Baleonoptera musculus
(blue whale)• Modern marine mammal
• Basilosaurus• “king lizard”• w/ 0.5m hind legs, w/ some
bones similar to those of land mammals
• Ambulocetus natans• “walking whale that swims”• Skeletons found in Pakistan• Has a long, low body w/ short,
powerful limbs• Descended from land-living
carnivorous hoofed animals http://www.whale-info.com/bluewhale.html, http://www.bbc.co.uk
Paleontology
Problems with the fossil record1. Fossils form by chance2. Quality of fossils varies3. Fossil reconstruction
requires thorough knowledge of anatomy
4. Dating of fossils is achieved through various methods
http://eweb.furman.edu
Paleontology
Comparative EmbryologySimilarities in early development
Closely-related organisms have similar stages in embryonic development1. Tail2. Pharyngeal
slits/pouches/arches
http://www.nature.com/nrg/journal/v7/n11/fig_tab/nrg1918_F2.html
Similar genes at
work
Similarities in early
development
Shared heritage from a common ancestor!
Comparative AnatomySimilarities in body structures
http://hippie.nu/~unicorn/tut/img/basics/animalanatomy/wing-feathers.jpeg, http://www.uksafari.com/jpeg2/batwing2.jpg, , http://www.bugshop.com.au/images/Butterfly%20Wing.jpg
Similar structures
Homologous
Similar structure, different function
Due to common ancestry
Analogous
Similar appearance
and function
Different origins
Similarities in body structures and evolution
Divergent evolution or adaptive radiation• Common origin• Descendants appear different externally but are similar internally
Convergent evolution• Different origins• Descendants independently evolve similarities when adapting to similar environments
Comparative Anatomy
http://itc.gsw.edu/faculty/bcarter/histgeol/paleo2/limbs.jpg
Comparative Anatomy
http://www.evolution-textbook.org/content/free/figures/22_EVOW_Art/07_EVOW_CH22.jpg, http://www.carolinabeachtoday.com
Comparative Anatomy
Vestigial structures• structures that are of
marginal or little use to an organism
• e.g. coccyx and wisdom teeth in humans, hipbones and pelvis in whales, anal spurs in pythons and boas
• evolution is a remodelling process: ancestral structures may be modified as they take on new roles
http://3.bp.blogspot.com/-KAdBIaT796A/Ta-KqBdscqI/AAAAAAAAABQ/KWFe8Ks8Oic/s1600/whale-vestigial-structure.jpg
, http://en.wikipedia.org/wiki/Anal_spur
Comparative Anatomy
Biochemistry and Molecular BiologySimilarities in chemical compounds
Species pairs % difference in nucleotide sequences
& chimpanzee A 2.5& gibbon B 5.1& old world monkey C 9.0& new world monkey D 15.8& lemur E 42.0
A B C
D E
• Similarity of DNA b/w individuals of a species:related individuals > unrelated individuals
• Two spp. judged to be closely related by other criteria have a proportion of their DNA in common than more distantly related spp.
http://web.scc.losrios.edu/evanst/, http://andfinally.tv/2009/06/baby-gibbon-mothered-247-by-human/, http://www.datensklaven.de/?tag=animals, http://eco-stride.blogspot.com/2007/10/monkey-mobilized-in-columbia.html,
http://www.naturalphotos.com/sekercioglu/madagascar/pages/MG8-TnZoo-RTLE.htm
,
***Hemoglobin: protein that transports O2 in blood
Central dogma of mol bio:
DNA RNA proteinsStructure of proteins dictated by DNA sequence Similar proteins ~ similar DNA sequence
***
Biochemistry and Molecular Biology
Similarity of chemical compounds• sequences
copied from a common ancestor
• common genetic code passed on along all the branches of evolution
Degree of relatednes
s
Biochemistry and Molecular Biology
BiogeographyDistribution of species in space and through time
Gondwana broke up around 160 MYA eventually forming modern Antarctica, South America, Africa, Madagascar, Australia-New Guinea, and New Zealand, as well as Arabia and the Indian subcontinent
http://planet.uwc.ac.za/nisl/biodiversity/loe/images/pic231.gif
Modern species present on a land mass evolved from ancestors that inhabited those regions.• species are not
distributed only according to where they can survive
http://evolution.berkeley.edu/evolibrary/article/history_16, http://faculty.scf.edu/odaffej/WasDarwinWrong.3/WasDarwinWrongEDIT6.html
Islands have many endemic species that are closely related to species of the nearest mainland or neighboring island.
http://myweb.rollins.edu/jsiry/c1x17b-finches.jpg, http://www.galapagosisland.net/galapagos_islands/map.html
Islands have many endemic species that are closely related to species of the nearest mainland or neighboring island.
http://bonvito.files.wordpress.com/2010/11/carlito.png
Islands have many endemic species that are closely related to species of the nearest mainland or neighboring island.
http://people.eku.edu/ritchisong/birdbiogeography1.htm
http://people.eku.edu/ritchisong/wallacesline2.gif
Wallace Line - imaginary line separating ecozones of Asia and Wallacea. West of the line are found organisms related to Asiatic species; to the east, a mixture of species of Asian and Australian origin is present.
http://people.eku.edu/ritchisong/554images/Zoogeographical_regions.jpg
http://worldpress.org/images/maps/world_600w.jpg