Unit 4 Flashcards
(37 cards)
natural selection
Survival of the Fittest (and elimination of the weak)
stabilizing selection
When individuals on both ends of the curve have lower fitness than individuals in the middle.
directional selection
When individuals at one end of the curve have higher fitness that individuals in the middle or at the other end.
distributive selection
Individuals at the upper and lower ends of the curve have higher fitness than individuals near the middle.
artificial selection
Selective breeding by which humans use animal and plant breeding to selectively develop a particular trait to reproduce
Biogeography
EVIDENCE OF EVOLUTION: the idea of how life is distributed on the planet. (organisms traits fit to survive where they live)
fossil record
EVIDENCE OF EVOLUTION: Database that we can reference to determine how old organisms are and where they belong in the order of current and ancient animals
Embryology
EVIDENCE OF EVOLUTION: the study of embryos and development. (we look the same at embryo stage showing we have a common ancestor)
Comparative anatomy
EVIDENCE OF EVOLUTION: comparing analogous, vestigial, and homologous structures within living things
Analogous structures
similar function different structure (species not related)
Homologous structures
similar structure, different function (suggests recent common ancestry - closely related)
vestigial structures
traits or characteristics that an organism possesses but no longer serves a function
Molecular evidence
EVIDENCE OF EVOLUTION: descent of species can be traced using genetic (protein sequences) similarities and/or differences
Darwin’s theory of evolution
Individuals with adaptive traits—traits that give them some advantage—are more likely to survive and reproduce
evolution
the change in the heritable characteristics of biological populations over successive generations
Charles Lyell and his beleifs
Earth’s geological features were formed gradually over vast periods of time by the same natural processes that are still in operation today
Lamarck and his hypothesis
proposes that organisms inherit characteristics acquired during their lifetime
Malthus beleifs
if human population grew unchecked, there wouldn’t be enough living space and food for everyone
fitness
an organism’s ability to survive and reproduce in a given environment
adaptation
species becomes better suited to its environment through natural selection, leading to changes in traits that improve fitness
common descent
different species share a common ancestor in the distant past, meaning they evolved from a single, original species
Descent with Modification
all living organisms are descended from a common ancestor but have diverse traits through natural selection and other evolutionary processes
Evidence of evolution
Biogeography, fossils, comparative anatomy, embryology, molecular evidence
directional natural selection
When individuals at one end of the curve have higher fitness that individuals in the middle or at the other end.
