Evolution Flashcards
The change in the genetic makeup of a population with time
Evolution
Evolution is explained by the constant propagation of new ___ in the __ of a species, some of which impart an ___ ____. All living things are descendents from a single ____ ____. Each of these organisms arose as a direct result of some genetic alteration in the species that lived before them. Most evolutionary changes occur _____ over a long period of time
variations, genes, adaptive advantage, common ancestor, slowly
discredited theory of evolution that held that new organs or changes in existing ones arose because of the needs of an organism
Lamarckian evolution
Lamarckian evolution proposed that the amount of change was throught to be based on the ___ or ____ of an organ. Any useful characteristic acquired in one generation was thought to be ____ to the next. This was called an ___ ______.
use, disuse, transmitted, acquired characteristics
In reality, only changes in the DNA of the __ ___ can be inherited. In contrast, changes acquired during an individual’s life are changes in ___ ___.
sex cells, somatic cells
In charles darwin’s theory of ____ selection, pressures in the ____ select for an organism most fit to survive and _____.
natural, environment, reproduce
The ability to survive and reproduce
fitness
Darwin said a particular species that has ___ ____, allowing it to ___ effectively with the immediate environment, will produce more ____ than individuals with less _____ genetic traits. The genes of parents that are more fit are therefore ___ ___ to more offspring and become increasingly prevalent in the ___ ___. There are ___ agents leading evolutionary change
beneficial traits, cope, offspring, favorable, passed down, gene pool, 6
When more offspring are produced than can survive, and therefore, the food, air, light and space are insufficient to support the entire population
overpopulation
Offspring naturally show differences in their characteristics compared to those their parents; later attributed to mutations
variations
When the developing population must compete for the necessities of life. Many young must die, and the number of adults in the population generally remains constant from generation to generation
competition
When some organisms in a species have variations that give them an advantage over other members of the species
natural selection
When the individuals that survive live to adulthood to reproduce and thus transmit favorable variations or adaptations to their offspring. These favored genes gradually dominate the gene pool
inheritance of the variations
When over many generations of natural selection, the favourable changes are perpetuated in the species. The accumulation of these favourable changes eventually results in such significant changes in the gene pool that we can say a new species has evolved. These physical changes in the gene pool were perpetuated or selected for by environmental conditions
evolution of new species
____ is the evolution of new species, which are groups of individuals that can _____ freely with each other but not with members of other species. ___ ___ is impossible between different species.
speciation, interbreed, gene flow
Different selective pressures act upon gene pools of each group, causing them to evolve _____. Changes in the environment, ___ / _____ to new environments, natural selection, ___ ___ and ___ are all factors that can lead to speciation
independently, migration, adaptation, genetic drift, isolation
Before speciation, small local populations called ___ often form within a species. Members of the same deme ___ one another more closely than members of other demes. They are closely related genetically since ____ between members occurs more frequently. They are also influenced by similar environmental factors and thus are subject to the same ____ ___
demes, resemble, mating, selection processes
If demes become ____ speciation may occur. When groups are isolated from each other, there is no __ ___ among them. Any difference arising from mutations or new combinations of ___ will be maintained in the ___ ___. over time, these genetic differences may become significant enough to make mating ____. If the gene pools within a species become sufficiently different so that two individuals cannot mate and produce ____ offspring, two different species have developed, and one or more new species have formed.
isolated, gene flow, genes, isolated population, impossible, fertile
Genetic and eventually ____ isolation often results from the ___ ____ of a population
reproductive, geographic isolation
The evolutionary relationships among species alive today
phylogeny
When two species from different ancestors develop similar traits due to exposure to similar environments
covergent evolution
when two species from a more recent ancestor face similar environments and thus develop similar adaptations
parallel evolution
Occurs when species with a shared ancestor develop differing traits due to dissimilarities between their environments
divergent evolution
the emergence of a number of lineages from a single ancestor species; differences are due to a distinct lifestyle / niche
adaptive radiation
all members of a particular species inhabiting a given location
population
the total of all the alleles for any given trait in the population
gene pool
the decimal fraction representing the presence of an allele for all members of the population for this particular gene
gene frequency
For any given gene, ______ = 1, where __ represents the frequency of the recessive allele, and p represents the frequency of the ____ allele
p + q, q, dominant
Evolution can be viewed as a result of changing ___ ___ within a population. Gene frequency is the relative frequency of a particular ____. When the gene frequencies of a population are not changing, the gene pool is ___ and the population is not ____. However, this is only true in ____ situations
gene frequencies, allele, stable, evolving, ideal
Ideal conditions assume that the population is very ____, no ___ affect the gene pool, that mating between individuals in the population is ____, there is no ____ ___ of individuals into or out of the population, and the genes in the population are equally ___ at reproducing
large, mutations, random, net migration, successful
The ______ equation says that for a gene with only two alleles, ________, where p^2 is the frequency of the dominant _____, 2pq is the frequency of the _____, and ___ is the frequency of ____ homozygotes. This equation may be used to determine gene frequencies in a ___ ___ in the absence of ____ change (ideal conditions). This describes an ____ or a nonevolving population
hardy-weinberg, p^2 + 2pq + q^2, homozygotes, heterozygotes, recessive, large population, microevolutionary, equlibrium
Real populations have ____ gene pools and ____ populations. The agents of ____ ____ are all deviations from the five conditions of a hardy-weinberg population
unstable, migrating, microevolutionary change
In natural selection, genotypes with favourable variations are selected through natural selection and the frequency of favorable genes ____ in the ___ __. Genotypes with low __ ___ tend to disappear
increases, gene pool, adaptive values
Gene ____ change allele frequencies in a population, shifting gene ____ by introducing ___ ____. These mutations can either be favorable or _____ for the offspring
mutations, equilibria, additional alleles, detrimental
If mates are not random chosen but rather ___ according to criteria such as ___ and ____ (___ ___) the relative genotype ratios will be affected and will depart from the predictions of the hardy-weinberg equilibrium
selected, phenotype, proximity, sexual selection
Changes in the composition of the gene pool due to chance; more pronounced in smaller populations or new populations
genetic drift/founder effect
Migration of individuals between populations will result in a ____ or ___ of genes, thus changing the composition of a population’s gene pool
loss, gain
the process by which minerals replace the cells of an organism
petrification
impressions left by an organism
imprints
hollow spaces in rocks as the organisms within decay
molds
When minerals are deposited in molds
casts
___ ____ have the same basic ___ features and ___ origins. They demonstrate similar evolutionary patterns with ___ ___ of form due to differences in exposure to evolutionary forces. Although the origins and anatomical features of these structures are similar, their ___ may not be
homologous structures, anatomic, evolutionary, late divergence, function
___ ___ have similar functions but may have different evolutionary origins and entirely different patterns of ____. These demonstrate a ____ resemblance that cannot be used as a basis for _____
analogous structures, development, superficial, classification
The stages of development of the ___ resemble the stages in an organism’s ___ ____.The ___ the stage at which development begins to diverge, the ____ dissimilar the adult organisms will be.
embryo, evolutionary history, later, more
Most organisms demonstrate the same basic needs and ___ processes. They require the same __ and contain similar __ ___ and ___ __ forms. This suggests that all organisms must contain some ___ ___in common.
metabolic, nutrients, cellular organelles, energy storage, DNA sequences
The more _____ organisms shared a common ancestor, the greater the similarity of their ___ ____ such as enzymes, ____, ____, blood and genetic information. Thus we can conclude that all organisms are descended from a single ___ __ form
recently, chemical constituents, antibodies, hormones, common ancestral form
structures that have no known current function but apparently had some ancestral function
vestigial structures
Species multiplication is generally accompanied by ______ to lessen -__ ___. Separation of a widely distributed population by emerging ___ ___ increases ___ _____ and overtime interbreeding becomes impossible. ___ __ would be maintained even if the barrier is removed. Some examples are ___ and ___ ___
migration, intraspecific competition, geographic barriers, genetic adaptations, reproductive isolation, marsupials, darwin’s finches
first forms of life that required preformed molecules / depended on outside sources for food
heterotrophs
The presence of ____, ___, ammonia, ___ and ___ in primitive seas, and energy in the form of ____, electricity, ___ ____, cosmic rays, and _____ may have led to the synthesis of simple organic molecules such as _____, amino acids, purines, pyramidines, etc. These molecules dissolved in the ___ ___ and after many years, the simple ____ ____ combined to form a supply of _____
salts, methane, hydrogen, water, heat, solar radiation, radioactivity, sugars, primordial soup, monomeric molecules, macromolecules
Stanely L Miller circulated ____, ___, ___ and _____, with ____ ____. He found organic compounds such as ___, __ ___, ___ ___ and ___ ___ had been synthesized
hydrogen, methane, ammonia, water, electrical discharges, urea, hydrogen cyanide, acetic acid, lactic acid
colloidal protein molecules tend to clump together to form __ ____, a cluster of colloidial molecules surrounded by a shell of water. These droplets tend to possess a ____ internal structure. It is highly likely that such droplets developed on the ___ ___. A small percentage of these droplets possessing favorable characteristics may have eventually developed into the first ___ ____. These cells probably possessed __ ___ ___ and became capable of reproduction
coacervate droplets, definite, early earth, primitive cells, nucleic acid polymers
The primitive heterotrophs slowly evolved complex ___ __, enabling them to use a wider variety of nutrients. They evolved ___ ___ processes to convert nutrients into energy. However, theses organisms required nutrients at a ___ __ than they were being synthesize. life would have ceased if ___ ____ had not developed
biochemical pathways, anaerobic respiratory processes, faster rate, autotropic nutrition
organisms that are able to produce organic compounds, including energy-containing molecules, from substances in their surroundings
autotrophs
The pioneer autotrophs developed primitive ___ ___, capturing solar energy and using it to synthesize ____ from carbon dioxide and wter
photosynthetic pathways, carbohydrates
The addition of _____ ___ from photosynthesis converted the early atmosphere from a ___ to an ____. Some molecular oxygen was converted to _____, which functions in the atmosphere to block ____ ____. In this way, living organisms destroyed the conditions that made their _____ possible. Once molecular oxygen became a major component of the earth’s atmosphere, both heterotrophs and autotrophs evolved the biochemical pathways of ___ ___. Now, ____ exists between oxygen producing and ____ organisms
molecular oxygen, reducing, oxidizing, ozone, high-energy radiation, development, aerobic respiration, equilibrium, oxygen-consuming
All living organisms can be divided into four basic categories. The ___ __ include chemosynthetic bacteria, the ___ ___ include the green plants and ____, the ____ _____ include yeasts, and the ____ ____ include amoebas, earthworms, and humans
autotrophic anaerobes, autotrophic aerobes, photoplankton, heterotrophic anaerobes, heterotrophic aerobes
