Evolution Theory Flashcards
Define evolution
Genetic changes in populations that are inherited over successive generations / descent with modification
Characteristics of micro-evolution
Small scale changes within a species passed on to offspring
Results in genetic diversity in populations
Shorter timescale than macro-evolution
Characteristics of macro-evolution
Development of a new species from earlier species over many generations
Results in species diversity
Longer timescale than micro-evolution
Four types of evidence for evolution
Fossils and the fossil record
Descent with modification / homologous characteristics
Biogeography
Genetics
Define fossils
The remains or imprints of organisms, usually preserved in rocks
What is the fossil record?
An accumulation of all known fossils of different ages for a particular area
What is paleontology?
The study of fossils
What is a paleontologist?
A scientist who studies fossils
What is stratigraphy?
The classification of deeper rock layers as older and successive layers as younger
Define geological timescale
A system of chronological dating that classifies geological strata (layers of rock) in time
How do fossils provide evidence of evolution?
Simpler species are found in deeper, older rocks, while more recent and complex species are found in the upper, more recent rocks
Define homologous structure
Equivalent structures with the same body plan that might perform different functions
How do homologous structures provide evidence of evolution?
The same structure can be traced back to a common ancestor
Define analogous structure
Structures that do not have the same body plan but happen to perform the same function
What do analogous structures provide evidence of?
Convergent evolution
What is a vestigial structure?
Structures that persist in an organism even though they are no longer functional (e.g. pelvic girdle bones in whales)
What comparative anatomy is used as evidence for common ancestry of all life?
Identical DNA structure Identical protein synthesis process Same 20 amino acids Same metabolic processes and enzymes ATP as the universal energy carrier
How do genetics provide evidence of evolution?
More closely related species have more DNA sequences (+genes) in common
More distantly related species have fewer DNA sequences (+genes) in common
Define species
A group of living organisms that are capable of interbreeding and producing fertile offspring
What is discontinuous variation?
Variation in which types are grouped into discrete categories with few/no intermediate phenotypes
Typically single allele characteristics
(Use bar graph)
What is continuous variation?
Variation that has no limit on the value/variation that can occur within a population
Typically multiple allele characteristics
(Use line graph/histogram)
