BIOLOGY EOCT REVIEW Day 5: Evolution
Dec 14, 2015
CHARLES DARWIN
Traveled on the Beagle to the Galapagos Islands Studied 13 species of finches on the islands Hypothesized that all originated from 1
ancestor Explained his theory of NATURAL
SELECTION Published in On the Origin of Species Influenced by Lyell and Wallace Strayed from Lamarck’s “inherited traits”
theory
NATURAL SELECTION
Survival of the Fittest Fit = best adapted to environment for survival
Mice will display gray coloring rather than white
THEORIES OF EVOLUTION
Adaptations Changes in response
to the environment and becomes a new species
Required to survive in the changing world
Reproductive Isolation A species is
separated and becomes two separate species
EVOLUTIONARY TERMS
Speciation Creation of a new
species A species can mate
and produce viable offspring
Extinction A species ceases to
exist Can occur gradually
(rainforest plants) or as a mass extinction (dinosaurs)
Biodiversity Number of different
species/organisms
Biodiversity inside a classroom is much lower than the biodiversity outside
Inside: humans, insects
Outside: humans, insects, plants, animals, etc.
GENES
Gene Pool Genes available for
reproducing
Gene Flow Introducing genes
from one gene pool into another gene pool
FOSSILS AND PHYLOGENY
Radioisotope Dating Provides EXACT age
of fossils
Uses the half-lifes of radioactive isotopes (Carbon-14)
Relative Dating Provides
APPROXIMATE age of fossils
Generally, older fossils are found in rock layers beneath younger fossils
FOSSILS AND PHYLOGENY
Analogous Structures
Vestigial Structures Used by common ancestor but no longer
necessary
Homologous Structures
FITNESS AND SELECTION
Stabilizing Selection Selects for the central trait
Directional Selection Selects for one extreme trait
Disruptive Selection Selects for both extreme traits
PRINCIPLES OF NATURAL SELECTION
Variations exists within populations.
Organisms compete for limited natural resources.
Organisms produce more offspring than can survive.
Individuals with variations suitable for their habitat survive and reproduce.
BIOLOGICAL RESISTANCE
Natural selection allows for the resistant bacteria and pests to survive and reproduce offspring that are also resistant
Antibiotic resistance The overuse of antibiotics leads to “superbugs”
Pesticide resistance Farmers must increase the use of pesticides on
crops as pests become immune/resistant to doses