The Tree of Life, pt. 1
This group of animals went through an adaptive radiation after the dinosaurs disappeared.
Mammals
This feature is unique to birds among all modern animals, but was not originally evolved for flight.
feathers
The name for spontaneous change in DNA.
The term for random changes in allele frequency.
Genetic drift
The letter grade that corresponds to 79.22% in this course.
C
This type of mammal gives birth to the most developed offspring.
Placental mammals/placentals
Name for the group of ground-running dinosaurs that includes both birds and T. rex.
Therapods
The larger structure upon which genes are located.
Chromosome
The term for alleles moving among populations.
Gene flow
A _______ is the physical manifestation of the alleles of an individual. (Darwin used the term "trait")
Phenotype
The two main characteristics that distinguish mammals from all other animals.
Hair and mammary glands
Considered by most scientists to be the first fossil bird from 145 million years ago.
Archaeopteryx
The two general factors that cause mutation.
1) Error in replication, 2) Damage to DNA
The type of selection that makes male birds so pretty.
Sexual Selection
Each _______ determines the structure of one or more proteins, which perform a specific function in the cell.
gene
Mammals have this many more inner ear bones than reptiles.
2
A hypothesis suggested about how flight evolved in birds.
Flapping arms helped dinosaurs run faster. Gliding is a precursor to flight.
Different variations of a gene are called this.
alleles
The type of selection that removes extreme versions of traits from the population.
Stabilizing Selection
Term for the 'reproductive success' that is required for natural selection to occur.
Fitness
A vertebrate with four limbs.
Tetrapod
Modern bird with hooked claws that aid chicks in climbing.
hoatzin
This cell division process is a major source of genetic variation in sexually reproducing species.
Meiosis
The type of selection which maintains multiple alleles in a population.
Balancing selection
Directional selection that occurs when an allele lowers the relative fitness of a genotype.
negative selection