Quiz 2 Flashcards
Evolution results from
Self preservation
Evolution is not
Goal-directed , progressive
Not all traits are
Adaptive
Evolution is under
Genetic and historical constraints
There re what’s to fitness?
Trade offs
Pleiotrophy
= one gene;many traits
Multiple allelism
One trait; multiple alleles
Gene linkage
Alleles for depth -> correlated with beak width (a suboptimal trait)
What causes genetic constraints?
Lack of allele variation
What are fossils?
Direct physical evidence of what organisms lived, where they lived and what they looked like over approximatly 3.5 billion year history of life on earth
Where have fossils been discovered?
Rocks through out the world
What kinds of rocks are more likely to contain fossils?
Sedementary rocks (limestone, shale and sandstone) and clays
Rocks containing fossils are usually
Exposed ( mountain outcrop, natural hill side, edge of stream or quarry)
What is a fossilized made up of?
A model made up of sand risk and minerals
What are unlikely sources of fossils
Igneous I.e. volcanic, granite, basalt, purnice etc And metamorphic (slate , marble)
How do fossils form
Slow decomposition(stagnant water, acidic and oxygen poor) and rapid burial (water sand mud)
Intact fossil
Interior and exterior architecture preserved
Compression fossil
Weight compresses organic material cemented into shale , mudstone
Cast fossil
Interior decomp, exterior preserved.
Cavity is filled with mineral and debris
Per mineralized fossil
Extremely slow decomp, dissolved minerals gradually infiltrate cell interior hardens
Fossilization is a
Rare event
What is habitat bias?
Find more in certain enviornments that promote fossilization
Taxonomic bias
Hard body parts fossilize easier
Temporal bias
Time related the longer age you fossilized the harder things are to find
Abundance bias
Thing that lived in huge populations are more often fossilized
Transitional fossil forms
Fossils that reveal a pathway of anatomical change in a type of organism over time
Vestigial trait
A thing that we have but is no longer useful
Atavisms
Structures normally absent re-appear in related species; expression of genes from an ancestral species
Microevolution
Evolution occurring in real time; over a short enough period that it can be observed
Industrial melanism
Organisms darken because of change in industry
Homologies/homology
Similarity between characteristics of organisms that is due to shared ancestry(when specifies share a trait)
Structural homology
Similar anatomy among organisms due to a common ancestor
