Ch. 15 Tracing Evolutionary History Flashcards
Macroevolution
The main events in evolutionary history of life on Earth
- Using evidence from sequence of fossils at different sites (strata)
- eras -> periods -> epoch
What are the 4 eras?
1) Precambrian
2) Paleozoic
3) Mesozoic
4) Cenozoic
Do the record of rock tell the actual ages in years of fossils?
No. Only tells the chronicles of the relative age of fossils. The order of evolution.
Radiometric dating
A method for determining the age of fossils and rocks from the ratio of a radioactive isotope to the nonradioactive isotope of the same element in the sample
Continental Drift
A change in the position of continents resulting from the incessant slow movement (floating) of the plates of Earth’s crust on the underlying molten mantle. It has caused continents to periodically fuse and break up thru out geological history.
Pangaea
Super continent consisting of all the major land masses of Earth fused together; continental drift formed Pangaea near end of Paleozoic era
Laurasia
Northern landmass formed when continental drift split Pangaea during Mesozoic era
Gondwana
Southern landmass formed during the Mesozoic era when continental drift split Pangaea
What did Pangaea split into?
Laurasia and Gondwana
Plate Tectonic
Forces w/in planet Earth that causes movements of the crust, resulting in continental drift, volcanoes, and earthquakes
What is a result of mass extinction?
Massive dip in species diversity leads to explosive increase in diversity
How do key adaptations evolve?
1) Gradual refinement of existing structures for new functions
- exaptation
- structure adapted to alternate function
2) Changes that affect organism’s development
- mutations of genes
Exaptation
A structure that has evolved in one environment context and later becomes adapted for a different function in a different environmental context
Paedomorphosis
Retention of juvenile body features in an adult
What accounts for evolutionary trends?
Species that endure longest/greatest new # of species determines the direction of trend.
- unequal survival/reproduction/speciation
- evolution is response to interactions b/w organism and current environment
Phylogeny
Evolutionary history of a species/group of related species
Phylogenic trees
A branching diagram that represents a hypothesis about evolutionary relationships amongst organisms
- based on available evidence
Systematics
Scientific study of biological diversity and its classification
Binomial Nomenclature
A two-part, Latinized name of a species
- genus + species
Genus
In classification, the taxonomic category above species; first part of binomial
Taxons
A proper name in the taxonomic hierarchy used to classify organisms
What is the order of taxon?
1) Domain
2) Kingdom
3) Phyla (subphylum)
4) Class
5) Order
6) Family
7) Genus
8) Species
Convergent Evolution
Adaptive change resulting in non homologous (analogous) similarities among organisms; species from different evolutionary lineages come to represent each other (evolve analogous structures) as a result of living in very similar environments
Amino Acid Sequencing
determining the sequence of amino acid in polypeptide
- most precise
- degree of similarity in sequence = degree in phylogenetic relationship b/w species
What are the two tools of systematics for molecular biology?
1) Protein Comparison
2) DNA & RNA Comparisons
DNA – DNA hybridization
A method of determining the relatedness b/w different species by measuring the extent of hydrogen bonding between single strands of their DNA molecules; also refers more generally to hydrogen bonding b/w DNA from any two sources (for example, b/w an organism’s DNA and a chemically synthesized DNA probe)
DNA Sequence Analysis
Determination of nucleotide sequences of segments of DNA
Ribosomal RNA (rRNA) Sequence Analysis
Determination of nucleotide sequence in ribosomal RNA molecules
What are the three methods of DNA & RNA Comparisons?
1) DNA - DNA Hybridization
2) DNA Sequence Analysis
3) Ribosomal (rRNA) Sequence Analysis
Cladistic Analysis
The study of evolutionary history; specifically, the scientific search for monophyletic taxa (elades), taxonomic groups composed of an ancestor and all its descendants
Monophyletic taxa
a taxonomic group composed of an ancestor and all of its descendants
outgroup
in a cladistics study of evolutionary relationships among taxa of organisms, a taxon or group of taxa w/ a known relationship to, but not a member of, the taxa being studied
ingroup
a cladistics study of evolutionary relationships among taxa of organisms, the group of taxa that is actually being analyzed
Derived Characters
homologous features that have changed from a primitive (ancestral) condition and that are unique to an evolutionary lineage; features not found in ancestors of the lineage
Primitive Characters
homologous features in members of a lineage and also in the ancestors of the lineage; ancestral features (use outgroup)
Parsimony
in scientific studies, the search for the least complex explanation for an observed phenomenon
5 kingdom classification schemes?
1) Monera
2) Plantae
3) Fungi
4) Animalia
5) Protista
3 domain classification schemes?
1) Bacteria
2) Archaea
3) Eukarya
