EVOLUTION Flashcards
Development of the Idea of Evolution
-Greek
- Early Concept
- Xenophanes, Empedocles & Aristotle
Regarded fossils as evidence for former life
Greeks
Inheritance of acquired characteristics
( Neck of giraffes
Jean Baptiste de Lamarck
Changes happen in a population
Charles Darwin
Evidence of Darwinian Theory of Evolution
Perpetual Change
Common Descent
Everything came from a common ancestors
Homology
Similarities in anatomy
Ontogeny
Development of an organism from embryo to adulthood
Multiplication of Species
Speciation
Groups are separated by physical barrier
Allopatric
Divergence occurs without physical barriers (preference)
Sympatric Speciation
Adjacent population evolve into distinct species while maintaining contact along a common border
Parapatric
Formation of multiple
species from a single
population in response
to selective pressures
Adaptive radiation
Small changes are
accumulated over
time, causing
species change in a
population
GRADUALISM
Types of Gradualism
- phyletic gradualism
- punctuated equilibrium
- natural selection
Slow-but-steady
evolutionary change
Phyletic Gradualism
-Rapid changes prompted
by disruptive events
-May also be the result of
lacking fossil evidences
Punctuated Equilibrium
survival of the
most adapted in
the environment
Natural selection
Genetic variation
and change
within a species
Microevolution
•Occurrence of
different allelic
forms of a gene in
a population
• All alleles of all
genes in a
population form
the gene pool
Polymorphism
Forces of Evolutionary Change in Microevolution
Mutation
Change in frequency
of alleles/gene
variants in a gene
pool
Genetic Drift
exchange of genes
between populations
Gene Flow
Interaction of all
the other factors
“Forces” of Evolutionary Change in
Microevolution
-Major
evolutionary
events
-describes large-
scale events in
organic evolution
MACROEVOLUTION
