A form or structure modified to fit a changed environment
differential survival and reproduction of individuals within a population
the selective breeding of domesticated plants and animals
what are the oldest known fossils?
reveals that organisms have evolved in a historical sequence
What are the 3 most important points that came from Darwin's observations?
1. Individuals do not evolve, populations evolve
2. Natural selection can amplify or diminish
only heritable traits, acquired characteristics cannot be passed on to
3. Evolution is not goal directed and does not lead to perfection,
favorable traits vary as environments change
the similarity in characteristics that result from common ancestry
different forms of phenotypic characteristics
An example of natural selection
pesticide resistance in insects
Comparisons of DNA and amino acid sequences between different organisms reveal evolutionary relationships
history of life represented as a tree
Evolutionary Tree Diagram
change in heritable traits in a population over generations
a group of individuals of the same species living in the same place at the same time
What is the difference between microevolution and macroevolution?
Microevolution is a gradual adaptation of a species to its environment and does not produce a new species in the short term. Macroevolution is dramatic biological changes that begin with the origin of new species.
What are 3 causes of evolutionary change?
1. Natural Selection
2. Genetic Drift
3. Gene Flow
distinction in appearance between males and females of a species
What is an advantage of being a heterozygote instead of a homozygote?
Heterozygotes have greater reproductive success than homozygotes
Can natural selection create perfect organisms?
a group of individuals of the same species living in the same place at the same
How are insects and bacteria resistant to antibiotics or pesticides? What does this mean?
Spraying pesticides and taking antibiotics more than needed (or before you are
completely over your virus) can make the surviving insects and bacteria become
resistant and produce more resistant offspring.
when a new species is formed
What is the difference between allopatric and sympatric speciation?
Allopatric speciation is when a species is separated by geography. Sympatric Speciation is when a species is located in the same area.
More than one set of chromosomes
a group of organisms whose members can breed and produce fertile offspring, but
who do not produce fertile offspring with members of other groups
Know the types of reproductive barriers and be able to identify examples of each
Prezygotic (prevent mating or fertilization between species) and Postzygotic (prevent the development of fertile adults)
defines a species as a population or group of populations whose members have the
potential to interbreed in nature and produce fertile offspring
Biological species concept
Can fusion occur in a hybrid zone?
weak reproductive barriers between the two species, with considerable gene flow,
reverses speciation and two species become one again
many diverse species evolved from a common ancestor. Occur when a few organisms
colonize new unexploited areas and after a mass extinction
Which element was probably not present in the early, primitive earth?
what energy sources were present in early earth?
volcanic activity, lightening, uv radiation
What were the first organisms?
What were the first organisms composed of? RNA, DNA, or protein?
What similarities do protobionts and modern-day cells share?