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.
What are the categories of natural selection
Stabilizing, Directional, Disruptive
occurs when the environment selects against organisms of a population with extreme versions of a trait.
Stabilizing selection
Stabilizing selection favors an ___phenotype by selecting ______extreme variation.
average
against
the environment selects for an extreme characteristic
single phenotype is favored, causing the allele frequency to continuously shift in one direction
Directional selection
- the environment favors extreme traits in a population at the expense of intermediate forms, thereby splitting the population into two or more subpopulations.
- selection often drives _____
Disruptive selection
speciation
happens in large populations with lots of pressure for the individuals to find advantages or niches as they compete with each other for food to survive and/or partners to pass on their lineage.
Disruptive selection
The flow of alleles in and out of a population due to the migration of individuals or gametes.
gene flow
This variable flow of individuals in and out of the group not only changes the _______ of the population, but can also introduce new _______ to populations in different geological locations and habitats.
Gene flow
gene structure
genetic variation
It can occur when a small group of individuals leave in a population and establishes a new one in a geographically isolated region.
Genetic drift
Genetic drift is _____as it occurs in a result of pure chance, however, it affects small populations significantly unlike large populations that are not susceptible to change due to chance.
random
A dramatic decrease in genetic diversity caused by the formation of isolated small colony of individuals.
Founder effect
A genetic drift resulting from the reduction of a population due to natural hazards (earthquakes, floods, fires)
Bottleneck effect
How Do Geological Processes and Climate Change Affect Evolution?
First, the ____________ greatly influence the earth’s climate and thus help determine where plants and animals can live.
Second, the _________ has allowed species to move, adapt to new environments, and form new species through natural selection.
The_________have a major effect on biological evolution by determining where different types of plants and animals can survive and thrive and by changing the locations of different types of ecosystems
locations of continents and oceanic basins
movement of continents
long-term climate changes
, is any heritable trait that enables an individual organism to survive through natural selection and to reproduce more than other individuals under prevailing environmental conditions.
Adaptation, or adaptive trait
For natural selection to occur, a trait must be ______.
heritable
The trait in adaptation must also lead to _______, which enables individuals with the trait to leave more offspring than other members of the population leave.
differential reproduction
When environmental conditions change, a population of a species faces three possible futures: ______to the new conditions through natural or become selection, ____(if possible) to an area with more favorable conditions, ______.
adapt ; migrate; extinct
3 Classifications of adaptation
______(body covering, shape, defensive and offensive armaments)
________(making venom, secreting slime, phototropism)
_________(searching for food, mating, vocalizations)
Structural
Physiological
Behavioral
It is an adaptation in which one animal evolves to look like another animal; is a very effective adaptation, and it is crucial to the survival of many species.
Mimicry
______mimicry occurs when two different species look alike. This benefits both animals, as predators will typically avoid them all. This type of mimicry is common to many groups of butterflies.
Mullerian
_______mimicry, unusual type of mimicry(only a few cases in snakes are known), and it occurs when aharmful species copies an aposematic trait (e.g. coloration) of a less dangerous organism.
Mertensian
______mimicry,the mimetic organism (that is usually harmless and edible) copies the flashy traits of a venomous or poisonous organismpresent in its habitat in order to make predators think it’s a harmful species.
Batesian
_____ mimicry in this case are predators (or parasites) the ones that develop the traits of a more or less harmless species(or even of a beneficial one) in orderto be unnoticed by their preys or hostages.
Aggressive or Peckhamian
The _______ is a special case of mimicry that takes place whenan organism transforms some part of its body in order to seems like another part of its own body or even of the body of another member of its species(e.g. a male that mimics a trait from females).
automimicry (also known as intraspecific mimicry)
Natural selection can lead to an entirely new species. Under the process, called _____(two species arise from one).
speciation
_______ is the number of different species it contains (________) combined with the relative abundance of individuals within each of those species (_______)
Species diversity
species richness
species evenness
The species diversity of communities varies with their ____
geographical location
How does species richness affect an ecosystem?
According to the first hypothesis, the more _____an ecosystem is, the more ____it will be.
diverse; productive
Describes the role of anorganismplays in a community.
It is a species’ way of life in a community and includes everything that affects its survival and reproduction
Ecological niche or niche
have broad niches.
They can live in many different places, eat a variety of foods, and often tolerate a wide range of environmental conditions.
Generalist species
occupy narrow niches.
They may be able to live in only one type of habitat, use one or a few types of food, or tolerate a narrow range of climatic and other environmental conditions.
Specialist species
________ are those species that normally live and thrive in a particular ecosystem.
_________ are species that migrate into or are deliberately or accidentally introduced into an ecosystem.
-It is also referred to as invasive, alien, or exotic species
Native species
Nonnative species
Species that provide early warnings of damage to a community or an ecosystem are called _______
indicator species.
________is the complete disappearance of a species from Earth.
It occurs when species are diminished because of environmental forces (habitat fragmentation, global change, natural disaster, overexploitation of species for human use) or because of evolutionary changes in their members such as: (_____, ________, ______)
Extinction
geneticinbreeding, poorreproduction, decline inpopulationnumbers
_______species are especially vulnerable to extinction.
Endemic
