C3 Flashcards
The _______ is the “calendar” for events in Earth history.
geologic time scale
It subdivides all time into named units of abstract time called—in descending order of duration—eons,eras,periods,epochs, and ages.
geologic time scale
This GTS has the largest intervals of geologic time; hundreds of millions of years in duration.
Eons
_______ is the most recent eon and began more than 500 million years ago
Phanerozoic Eon
the second longest portions of geological time
divided time intervals of eons
subdivided by periods
Era
The enumeration of those geologic time units is based on_____, which is thecorrelationand________
stratigraphy; classification of rock strata
In biology, EVOLUTION is the ________ over several generations and relies on the process of _____.
change in the characteristics of a species
natural selection
_______is a process that results in changes in the genetic make up (gene pool) of a population through successive generations.
EVOLUTION
is genetic change that occurs over long time scales, resulting in large changes in heritable traits in a population; changes large enough that we consider this population a unique taxonomic group, or species
MACROEVOLUTION
is genetic change that occurs over small time scales and results in small changes in heritable traits
MICROEVOLUTION
What causes variations?
Recombination, Mutation
How Does variation occur??
During fertilization, sperm cell fuses with the ovum to create a ____.
Each ____contains hundreds to thousands of genes
On each pair of chromosomes, there are two genes that determine that trait to be inherited. This gene pair is called ____.
zygote
chromosome
allele
What are the Mechanisms of Evolution
Mutation, Natural selection, Gene flow, Genetic drift
Change in the DNA sequence within a gene or chromosome of a living organism
Mutation
______ reduce the fitness of an organism and increase the susceptibility to several illnesses and disorders.
Deleterious mutations
________can lead to the reproductive success and adaptability of an organism to its environment
Beneficial mutations
Classifications of Mutation:
____occur in gametes (eggs or sperm cells) and can be pass on to offspring.
____occur in non-reproductive cells and are not pass on to the following generation
Germ line mutations
Somatic mutations
It leads to an evolutionary change when some individuals with certain traits in a population have a higher survival and reproductive rate than others and pass on these inheritable genetic features to their offspring.
Natural selection
_____-the organisms best adapted to the environment are more likely to survive and reproduce
“Survival of the fittest”
: the process whereby earth’s
life changes over time through changes in the genes of populations
Biological evolution
_______ and ________ independently proposed the concept of natural selection as a mechanism for biological evolution.
Charles Darwin (1809–1882)
Alfred Russel Wallace (1823–1913)
A change in the genetic characteristics of a population from one generation to another is known as ____
biological evolution, or simply evolution.