2: Classification Flashcards
Phlogeny
the evolutionary development and diversification of a species or group of organisms, or of a particular feature of an organism
Fossil record
the record of the occurrence and evolution of living organisms through geological time as inferred from fossils
Precambrian Era
3500-600 MYA
1) 3500 MYA
2) 2200 MYA
1) earliest life on earth
first fossil of Procaryotes found
2) First Eucaryotes appeared
Procaryotes
Bacteria & archaens
single celled
microscopic
lack membrane bound organelles (eg nucleus)
Paleozoic Era
600-245 MYA
Life on land began with the Tiktaalik
- insects, fish, amphibians. reptiles
- liverworts, mosses and ferns
Tiktaalik
375 MYA
first vertebrae on land crocodile-like head & flattened body fish fins evolved into limbs of tetrapods skeleton could support its body lived in warm subtropical climate
Mesozoic Era
245-65 MYA
AGE OF REPTILES
mosses and ferns AND cone bearing plants (cycads & pines)
mammals and birds appeared 200-140 MYA
Five mass extinctions
Ordonvician-Silurian 443 MYA 85% marine spp. Late Devonian 359 MYA 50% of all genera Permian 248 MYA 96% marine spp, 70% land spp. Triassic-Jurrassic 200 MYA 50%marine and many vertebrate Cretaceous-Tertiary 65 MYA 75% plants & animals NO TETRAPODS MORE THAN 25KG SURVIVED
Mass extinctions benefit
opportunities for evolution of groups that can survive these events
Dinosaur extinction theory
Meteor
sediments contained iridium
fallout of huge dust cloud
blocked the suns rays and altered the climate/plant food sources (major decrease in oxygen in atmosphere
Cenozoic Era
65 MYA
all modern day multicellular animal groups represented
flowering plants dominate the plant world
Systematics
the branch of biology that deals with classification and nomenclature; taxonomy.
How organisms are related to each other through common ancestors
Homologous
similar in position, structure, and evolutionary origin but not necessarily in function.
“a seal’s flipper is homologous with the human arm”
Analagous
performing a similar function but having a different evolutionary origin, such as the wings of insects and birds.
Cladogram
Groups organisms based on common ancestors (clades)