Chapter 2 Flashcards
The Patterns of Evolution
Microevolution
Evolutionary change in the populations level
Speciation
When an ancestral species gives rise to two distinct descendant species
Macroevolution
Large evolutionary change, usually in morphology; typically refers to the evolution of differences among populations that would warrant their placement in different genera or higher-level taxa.
What is a fossil?
Any trace of an organism that lived in the past
What is the fossil record?
The worldwide collection of fossils
What is the law of succession?
The general pattern of correspondence between fossil and living forms from the same locale.
Extinction and succession are the patterns we would predict if present day species are descended with modification from ancesters that lived before them in the same region.
What are transitional forms?
Species which whow a mix of features, including traits typical of ancestral populations and novel traits seen later in descendants.
How are transitional fossils useful?
They document the past existance of species displaying mixture of traits typical of disctinct groups of organisms. They may be predicted before they are found, allowing biologist to test hypotheses about macroevolution.
What is homology?
“the study of likeness” Similar structures used for different functions, species share a common ancestor.
What is uniformitaranism? Who articulated it?
James Hutton; it is the clain that geological processes taking place now worked similarly in the past. A challange to catastrophism. Stated that the earth was less than 10,000 years old.
What is relative dating?
The effors of Hytton to put the rock formations and fossil-bearing strata of Europe in a younger to older sequence. It was an exercise in logic based on reasonable assumtion.
Chronology of relative dates
Geological time scale of fossils based on relative dating.
Radiometric dating:
Technique which uses unstable isotopes of naturally occurring elemens. Meaning that they change into either different elements or different isotopes of the same element. Each isotope decays at a particular and constant rate, measured in a unit called a half life.
How old is the earth?
Well over 3.5 billion years old.