Terms in this set (71)
structure similarities found in more than one species that share a common ancestor. Similar parts but different functions
Structures that serve the same function but do not share a common ancestor
Traces of a structure that may have had an important function in a species ancestors, but has no clear function in the modern species. structure no longer needed.
preserved remains or markings left of by organisms
chronological collection of life's remains in the rock layers, recorded during the passage of time
Species of organisms living on Earth today descended from...
Descent with Modification
Each living species has descended, with changes, from other species over time
An inherited trait that increases an organism's chances of survival
Each individuals has a unique combination of inherited traits
it will survive
The more variation within a species, the more likely...
Individuals compete for limited resources. Not all individuals survive to adulthood
The individuals with the best traits / adaptations will survive and have the opportunity to pass on it's traits to offspring
Natural selection acts on the...
Hardy-Weinberg equilibrium rules
No net mutations
Migration ~ 0
Natural selection does not affect the alleles
occurs when the probability that two individuals in a population will mate is not the same for all possible pairs of individuals
The exchange of genes with another population
decreases genetic variation in population
change in the gene pool of a population due to chance
Formation of new species; This occurs when a species splits into two groups and those groups lose the ability to interbreed
condition in which a reproductive barrier keeps two species from interbreeding
Species occur in different areas; separation of populations as a result of geographic change or migration to geographically isolated places (physical barrier)
Species occur in same region, but occupy different habitats so rarely encounter each other
Species that breed during different times of day, different seasons, or different years cannot interbreed
Unique behavioral patterns & rituals isolate species identifies members of species attract mates of same species
Morphological differences can prevent successful mating
changes in species is slow and gradual, occurring in small periodic changes in the gene pool
evolution occurs in spurts of relatively rapid change with long periods of non-change
an individual's likelihood of survival and reproduction
The type of selection where intermediate values for a trait are favored over extreme values.
favors the formation of average traits
favors the formation of more-extreme traits
favors both extreme traits rather than average traits
a form of selection in which humans actively choose which traits should be passed onto offspring
The antibiotic is given to bacteria. The drug kills most of the bacteria, but the resistant bacteria survives and multiplies and quickly becomes the norm in the population
the total genetic information available in a population
determined by dividing the total number of a certain allele by the total number of alleles of all types in the population
changes in the DNA
Emigration and immigration cause ________ between populations and can thus affect gene frequencies
a change in allele frequencies due to random events. operates most strongly in small populations
occurs when certain traits increase an individual's success at mating
Geographic isolation(allopatric speciation)
results from the separation of population subgroups by geographic barriers
Reproductive isolation within the same geographic area is known as...
200,000 years ago to present day
Age of homo sapiens
She was the first known bipedal ancestor
Neanderthals and Homo Erectus
Types of closely related hominids to humans
study of the geographical distribution of fossils and living organisms
Law of Superposition
successive layers of rock and soil are layered on top of one another
Which is the most reliable method for determining fossil age
Process of change in characteristics over time
heritable and favorable
Natural selection can act if a trait is...
the environment causes similar phenotypes but different ancestors. similar to analogous structure
artificial selection is the same as
Organisms with high _______ reproduce more successfully than other populations
Embryology comparisons reveal that organisms look _____ in early development phases
Corresponding changes of two or more species that are closely associated. When 2 or more species change together
famous for the theory of evolution and Natural Selection, or 'Survival of the Fittest'
Known for his Theory of Inheritance of Acquired Characteristics. Proposed that life evolves of changes.
Theory of Inheritance of Acquired Characteristics
evolution was the "acquired traits" of a species that is inherited by its offspring
the branch of biology and medicine concerned with the study of embryos and their development
a branch of biology that deals with proteins and nucleic acids essential to life
a diagram that depicts evolutionary relationships among groups. It is based on PHYLOGENY
the study of evolutionary relationships
a valuable tool that can be used to identify many objects ranging from plants to minerals.
When 2 or more related population/species become more and more different. this type of evolutions most often happens when a group of organisms is isolated from the main populations
evolution of an animal or plant group into a wide variety of types
hardy weinberg equations
p + q = 1
p2 + 2pq + q2 = 1
frequency of homozygous dominant condition (AA)
frequency of homozygous recessive condition (aa)
frequency of heterozygous condition (Aa)
the reduced genetic diversity that results when a population is descended from a small number of colonizing ancestors.