Test 2 Flashcards
Used to classify animals; involves hierarchy with different levels
Linnaean System of Classification
The science of classifying organisms
Taxonomy
Levels of classification
Kingdom Phylum Class Order Family Genus Species
Simple, single-called organisms that lack a nucleus
Prokaryotes
Thrive in extreme environments
Archaebacteria
Characterized by complex cells in which the genetic material is found within the nucleus
Eukaryotes
Typically unicellular organisms
Protista
History of organism lineages as they change through time
Phylogeny
Classification based on the number of shared physical characteristics. Does not account for evolution
Phenetic Classification
Classification based solely on phylogeny or shared common ancestry
Cladistic Phylogeny
The continuous genetic adaptation of organisms or species to their environment through time
Evolution
Floods and earthquakes must have periodically killed off organisms in parts of the world and new organisms from other parts of the world moved in to repopulate the regions
Catastrophe theory
Physical characteristics were acquired due to inner needs and inherited by future generations
Lemarckian evolution
Darwin’s two key observations
1) Members of a single species tend to vary a little
2) populations produce more offspring than needed for maintenance - results in competition for natural resources
Process by which favorable traits become more common and unfavorable traits become less common in successive generations of a population
Natural selection
Evidence of evolution
- homologous structures
- vestigial organs
- biochemistry
- early embryonic development
Body parts of similar origin, structure, and development but adapted for different functions
Homologous structures
Reduced or useless structures in plants or animals that are useful in other organisms
Vestigial organs
Study of chemical processes in living organisms; metabolism of vastly different organisms is based on the same complex compounds
Biochemistry
The remains of or trace of the presence of an ancient organism
Fossil
Preserved remains of an ancient organism
Body fossil
Indication of an ancient organism
Trace fossil
Occurs when an animal dies and is rapidly buried by soft sediments in low oxygen environments
Fossilization
Bones are converted into solid rock
Replacement
Certain traits show up in offspring without any blending of parent characteristics
Mendel’s Law of Inheritance
Permanent inheritable change in genetic material within cells
Mutation
Group of individuals capable of interbreeding and producing fertile offspring
Species
The origin of a new species from two or more individuals of a pre-existing one
Speciation
Process through which populations of the same species are physically isolated and evolve separately
Allopatric Speciation
Process through which new species evolve from a single ancestral species inhabiting the same geographic region; speciation through biological isolation
Sympatric Speciation
States that most species will show little change over most of their geological history. This is interrupted by abrupt, brief periods of change; suggest phyletic gradualism
Punctuated Equilibrium
Species split into two distinct species rather than one species gradually transforming into another
Phyletic gradualism
Process where organisms not closely related independently evolve similar traits as a result of having to adapt to similar environments or ecological niches
Convergent evolution
Process by which a species splits into two or more descendent species resulting in one similar species becoming more and more dissimilar
Divergent evolution
Body size increases during the evolution of species
Cope’s rule
Rapid expansion of a species over a relatively short period of time; usually caused by adaptive breakthroughs and extinction events
Evolutionary radiation
Appearance of key features or traits that allow the species to succeed
Adaptive breakthroughs
Death of one species which presents opportunities for another one
Extinction events
Disappearance of large numbers of plants and animals; caused by extraterrestrial impact, climate change, disease, predation, and natural disasters
Mass extinctions
Start of the universe
13.7 billion years ago
Age of the Earth
4.6 billion years
Same elements with different number of neutrons
Isotopes
Persist in environment
Stable isotope
Not stable and once formed, will decay to form stable ones
Radioactive isotopes
Amount of time for half of the original radioactive isotope to decay to the stable end product
Half life
Eons
Precambrian
Phanerozoic
Eras
Paleozoic
Mesozoic
Cenozoic
Process by which Terrestrial planets formed through the continuous collision of rocky debris. Rocks melted and denser material migrated to the center of the planet
Differentiation
Without oxygen
Anaerobic
1st life appears
3.8 billion years ago
Age of invertebrates
Early Paleozoic
Beginning of the Paleozoic when there is a great diversity of life
Cambrian explosion
Age of fishes
Middle Paleozoic
Age of amphibians
Late Paleozoic
Mammal-like reptiles
Therapsids
Age of the reptiles
Early Mesozoic
Age of the dinosaurs
Middle and late Mesozoic
Age of the mammals
Cenozoic Era
When humans split off from true apes
Between 8 and 6 million years ago
Shows traits of both apes and humans
Australopithecines
“Handy man”; 1st known species of genus homo
Homo Habilis
“To set upright”; evolved larger brains and made more elaborate tools that Homo Habilis
Homo Erectus
“Wise or knowing man”; larger brains and even more elaborate tools than Home Erectus
Homo Sapiens
Number of Kingdoms of Life
6: Archaebacteria, Eubacteria, Protista, Fungi, Plantae, and Animalia.
First organisms to move out of the sea onto land due to a development of a rigid stalk, root system, and vascular system.
Plants
What adaption freed plants of their dependence on moist conditions and allowed them to move further inland?
Seeds
Four measures of Geologic Time Scale
Eons, Eras, Periods, and Epochs
