Full Answer
How does genetic variation affect the rate of evolution?
Evolutionary adaptation to the environment occurred in both types of population; both were able to maintain higher numbers as the generations progressed. But the rate of evolution was more rapid in the mixed group than in the single-strain groups. The greater initial amount of genetic variation made possible a faster rate of evolution.
What is meant by evolution?
The natural process by which species gradually change over time... 1. Offspring are like their parents. 2. More offspring are produced each generation than can be supported by the environment. 3. There is variation between individuals within a species. Heritable characteristics can be passed from parent to offspring.
What is the relationship between heredity and DNA replication?
The information encoded in the nucleotide sequence of DNA is, as a rule, faithfully reproduced during replication, so that each replication results in two DNA molecules that are identical to each other and to the parent molecule. But heredity is not a perfectly conservative process; otherwise, evolution could not have taken place.
How does artificial selection affect genetic variation in a population?
If the population changes in the direction favoured by the breeder, it becomes clear that the original stock possessed genetic variation with respect to the selected trait. The results of artificial selection are impressive.
What is the connection between reproductive rate and evolution?
In the present theoretical study we show that a faster evolutionary rate can decrease the abundance of newly formed species and thus decrease long-term biodiversity. This leads to the paradoxical result that sexual reproduction can increase genetic variation but reduce species diversity.
What is the connection between reproduction rate and evolution quizlet?
In a large sexual population, mutation that occur in separate lineages can be joined together by sexual reproduction, so the rate of evolution is faster. It creates new genotypes by combining new mutations or rare alleles, increasing variation.
Why is reproduction so important to evolution?
As the process of natural selection, a crucial element of evolution can only be possible when the organisms reproduce sexually. It transfers the unique characteristics of the parent organism to their offspring (inheritance), which can only be done through sexual reproduction.
What is reproduction in evolution?
reproduction, process by which organisms replicate themselves.
What is the most important factor in evolution quizlet?
Natural selection- most influential in bringing about evolutionary change, it is also the one to produce an adaptive change, that is, change that results in the population being better adapted to its environment.
How does evolutionary change occur quizlet?
Natural Selection: is a mechanism of evolution that occurs when there is heritable variation for a trait and individuals with one version of the trait have greater reproductive success than do individuals with a different version of the trait.
How has reproduction affect evolution?
Reproduction and Evolution To get diversity in individuals, genetic differences are required, and different phenotypes must be expressed. Since sexual reproduction is more conducive to driving evolution than asexual reproduction, much more genetic diversity is available for natural selection to work on.
What is evolution of human reproduction?
The evolution of reproductive organs arrived with the development of gonads that produced sperm and eggs. These cells develop through meiosis, an adaption of mitosis, which reduced the number of chromosomes in each reproductive cell by half, while increasing the number of cells through cell division.
What is the importance of reproduction?
Reproduction is the process of creating new species or organisms. Sexual and asexual reproduction are both possible. The continuity of generation depends upon reproduction. It ensures the survival of like individuals from generation to generation.
Why is reproduction called a vehicle of organic evolution?
Young ones replace the old and dying ones. These young ones feed, grow and reproduce again. Reproduction also helps in increasing the population of the species. Reproduction acts as a vehicle of organic evolution by transmitting advantageous variations to the offspring.
Why is reproduction important for species survival?
Reproduction is vital to the success of a species. For a species to survive it must be able to produce more offspring than it loses though old age, disease, and predation. Living things can reproduce in different ways – asexual reproduction and sexual reproduction. A bacterium reproduces by asexual reproduction.
How is reproduction used in real life?
0:274:13Sexual Reproduction Humans | Genetics | Biology | FuseSchoolYouTubeStart of suggested clipEnd of suggested clipWhich is a tube running down the inside of the penis. The other sperm is mixed with secretion fromMoreWhich is a tube running down the inside of the penis. The other sperm is mixed with secretion from glands to produce a liquid called semen semen helps carry the sperm into the female reproductive.
Which of the following contributes to evolution?
There are four forces of evolution: mutation, gene flow, genetic drift, and natural selection.
Which of the following contributes evolutionary change quizlet?
Mechanisms of Evolutionary Change Mutation. Gene flow. Genetic Drift. Non-random mating/sexual selection. Natural selection.
What are the processes of evolution?
They are: mutation, non-random mating, gene flow, finite population size (genetic drift), and natural selection.
What is the scientific theory of evolution?
The theory of evolution is based on the idea that all species? are related and gradually change over time. Evolution relies on there being genetic variation? in a population which affects the physical characteristics (phenotype) of an organism.
What is the effect of genetic variation on the rate of evolution?
Genetic variation and rate of evolution. The more genetic variation that exists in a population, the greater the opportunity for evolution to occur. As the number of gene loci that are variable increases and as the number of alleles at each locus becomes greater, the likelihood grows that some alleles will change in frequency at the expense ...
How has artificial selection improved the lives of animals?
Thirty years of selection for increased egg production in a flock of White Leghorn chickens increased the average yearly output of a hen from 125.6 to 249.6 eggs. Artificial selection has produced endless varieties of dog, cat, and horse breeds. The plants grown for food and fibre and the animals bred for food and transportation are all products of age-old or modern-day artificial selection. Since the late 20th century, scientists have used the techniques of molecular biology to modify or introduce genes for desired traits in a variety of organisms, including domestic plants and animals; this field has become known as genetic engineering or recombinant DNA technology. Improvements that in the past were achieved after tens of generations by artificial selection can now be accomplished much more effectively and rapidly (within a single generation) by molecular genetic technology.
How to measure variability of a gene locus?
One simple way of measuring the variability of a gene locus is to ascertain what proportion of the individuals in a population are heterozygotes at that locus. In a heterozygous individual the two genes for a trait, one received from the mother and the other from the father, are different. The proportion of heterozygotes in ...
Why is it important to understand gene variability?
Measuring gene variability. Because a population’s potential for evolving is determined by its genetic variation, evolutionists are interested in discovering the extent of such variation in natural populations. It is readily apparent that plant and animal species are heterogeneous in all sorts of ways—in the flower colours and growth habits ...
What is the problem with morphological variation?
One problem with morphological variation is that it is not known how much is due to genetic factors and how much may result from environmental influences. Animal and plant breeders select for their experiments individuals or seeds that excel in desired attributes—in the protein content of corn (maize), for example, or the milk yield of cows.
When did genetic variation start?
The origin of genetic variation: mutations. Life originated about 3.5 billion years ago in the form of primordial organisms that were relatively simple and very small. All living things have evolved from these lowly beginnings.
Which type of adaptation to the environment occurred in both types of population?
Evolutionary adaptation to the environment occurred in both types of population; both were able to maintain higher numbers as the generations progressed. But the rate of evolution was more rapid in the mixed group than in the single-strain groups. The greater initial amount of genetic variation made possible a faster rate of evolution.
How does sexual reproduction increase genetic variation?
A. Sexual Reproduction increases genetic variation because random mutations can be shuffled between two organsims
Which is larger, testes of species two or species one?
Testes of species two are larger than testes of species one
Where are homologous chromosomes aligned?
Homologous Chromosomes are aligned at the equator of the spindle
Do prokaryotic organsims reproduce asexually?
C. Since prokaryotic organsims reproduce asexually, there is no mechanism for them to add genetic diversity for evolution
Is a cell identical to another cell formed from the same meiosis I event?
It is identical to another cell formed from the same meiosis I event
How does HIV evolve?
SHORT-SIGHTED EVOLUTION (within-host selection) - the strains of the HIV population inside the host evolve in response to selective pressures from the host's immune system, eventually resulting in the collapse of the immune system and the death of the host causing HIV's own extinction; it evolves itself out of existence. One example is coreceptor switching. During the course of an infection, virions using the coreceptor CXCR4 instead of CCR5 (coreceptor switching, CCR5 to CXCR4) are favored by natural selection - via short-term advantages in survival and reproduction - within the host and become numerically dominant but they do not get transmitted to new hosts and they hasten the collapse of the immune system and the death of the host. Natural selection cannot anticipate the future and "look" ahead to "see" that the short term success of X4 virions will lead to the extinction of the HIV population.
What is the virion of a virus?
The envelope around the virion and the cell membrane fuse, releasing the contents of the virion into the cell. The contents of the virion include the virus' diploid genome (two identical RNA molecules) and three proteins (reverse transcriptase, integrase, and protease). Reverse transcriptase will transcribe the viral RNA genome by synthesizing viral DNA in the cytoplasm of the host cell using the host cells' ATP and nucleotides. The viral DNA enters the host cell's nucleus, and integrase splices viral DNA into the host cell's genome. The viral DNA is then transcribed to viral mRNA by the host cell's RNA polymerase. The viral mRNA is translated into proteins by the host cell's ribosomes. Protease is involved in the production of viral proteins in the host cell.
What is the process of replication?
The replication process begins when a virion attaches to the protein CD4 on the surface of particular macrophages and T cells. It also attaches to a coreceptor (another protein) on the cell surface to complete the process of binding to the host cell.
What is a virion?
A virion (= virus particle) is the form of a virus that exists extracellularly during the infectious (extracellular) phase when it can be transmitted from host to host. This is in contrast to the intracellular or parasitic phase during which time the virus replicates.
What is the difference between transmission rate and natural selection?
TRANSMISSION RATE (between-host selection) - with frequent transmission from one host to a new host (= susceptible indiv.) natural selection favors increased virulence, whereas infrequent transmission favors reduced virulence, i.e. less severe strains. In other words, those traits of HIV that increase its ability to infect new hosts (rapid replication, evasion of immune system, large population sizes) may also cause HIV to kill its host.
What is the first step of genetic information?
first step (RNA ➝DNA)= backward flow of genetic information
What happens if hosts rarely exchange partners?
if hosts rarely exchange partners - more virulent kills before opportunity for transmission and does not do as well as less virulent
