Why is genetic diversity important?
967402
Because when you keep breeding close relatives you not only get the "good" traits but you get the "bad" traits in the next generation as well.  When you mix the genetic pool you cut the odds of the bad traits being carried to the next generation.\n\nAn example of this would be purebred dogs.  Many purebred dogs have specific defects in each breed because that gene was carried forward into the next generation as well as the good or desirable genes.\n\nMutts rarely have those types of problems.
297557
I tend not to think so because the benefits of many advances are not likely to reach all of humanity, and although I dont consider myself a dooms-dayer the lack of foresight by scientist could create bigger problems than they fix. One example that alarms me is the genetic modification of corn, a wind pollinated crop. Genetic polution from these crops has accidentally spread to ancient and wild varieties of the species, and could threaten the genetic diversity that we will likely need for the future. various projects involving modifications to bacteria and viruses also have me concerned because of potential unforseen consequences.
828336
Yes, of course it does. Breeding within a limited population always increases the incidence of recessive gene expression. Interestingly, a lot of these societies practice consanguineous marriage, which further amplifies the risk.
711783
Evolution doesn't cease to exist simply because there is no need for it.  Genetic variation and mutation are always going to occur.  However, the 'natural selection' aspect of it may not be applicable.
1002548
Every living being is trying to reproduce and have successful, surviving, reproducing offspring.  In every reproduction there is a chance of mutation, that one of the genes will function differently.  Often these changes in function cause a defect or a disadvantage, and the creatures with these mutations will die out without reproducing.  However, if the different function results in a significant advantage (making better use of a current food source or enabling the usage of a new food source) than the offspring with that mutation will become more likely to survive and the mutation will become the norm until a new mutation replaces it or environmental conditions change.\n\nThe diversity of life on Earth stems from life forms mutating and making use of all the millions of possible food sources that exist.
871249
1.Meiosis encourages genetic variability by:\na. Creating Haploid sex cells, this allows for the creation of a unique organism.\nb. Crossing over of the chromatid pairs allows for greater variation.\n2. The two parents have the recessive trait for the differing phenotype.  The offspring has the genes of four parents.\n3.Incomplete Dominance.
285424
no. There is much diversity
163988
The four priciples are:\n1. More individuals are born than survive to reproduce \n2. Heritable variation exists among individuals \n3  Struggle for existence or competition\n4. Adaptation
18875
Both are required. Variation in the population provides something for natural selection to act on. Mutation is one way to generate variation. Recombination  during meiosis is another. This sounds like a trick question. The correct answer is not one or the other--you would have to explain variation. One part of the process generates choices, the other part of the process "chooses" among the available options.
1036161
DNA is a way of storing information.  But that is far from intelligence.  Nothing senses changes in the environment and *decides* that it needs to change the organism to survive.\n\nYou are on the right track that there is an *element* of "luck" involved.    Randomness creates *variation*.  But there are two corrections you should know:  (1) Mutation is not the only source of randomness; and (2) Randomness is not the only thing driving evolution ... i.e. EVOLUTION IS NOT BLIND LUCK.\n\n1. Random mutations are improbable, but given huge numbers of replications, and huge amounts of time, there are *many* chances for mutations to occur, and those that produce some slight advantage tend to get propagated slightly better into future generations.  \n\nBut the invention of sexual reproduction took that randomness to a whole new level.   DNA from two different individuals could produce *huge* numbers of different combinations.  This allows improvements to propagate much faster into future generations, and allowed much faster adaptations to a changing environment.\n\n2. It's really important to know that EVOLUTION IS NOT JUST RANDOMNESS (BLIND LUCK).  Evolution is driven by 3 ingredients: variation + selection + time.  Randomness produces the *variation* ... but the selective pressures are NOT random.  \n\nFor example, a mammal may have several litters of offspring, say 20 in total.  Randomness produces the *variation* that some of these will be more hairy than their siblings.  But there is *nothing* random about the fact that those offspring with more hair may survive better in a colder environments and therefore produce more babies.  (E.g. if the environment is getting colder, or if some members want to, say, push a little further north.)  Add the ingredient of *time* and a much hairier subspecies can arise and get separated from the parent species ... and even more *time* and the subspecies can completely lose the ability to mate with the parent species, and you have two different species.\n\nSummary: randomness supplies the sparks of evolution, but selective pressures in the environment + time, provide the fuel.
477782
Genetics and evolution.
596251
Ideally you would want the largest number possible. If you use too few people then there would not be enough variety in their genes.\n\nEventually the entire population's genes would be very similar and the members of the population would have similar strengths and weaknesses eg. if one member of the population is not resistant to a particular virus, then because of the genetic similarity to other members it is quite likely that the entire population would not be resistant. It would be possible for them to be wiped out by a single virus (or other threat).
207195
Genetics and Environment
17735
These two processes are mechanisms that increase genetic diversity in organisms that reproduce by sexual reproduction.
180661
Do you mean in humans? Loss of biological diversity in humans is caused in part by genetic drift. Genetic drift is a random loss of genetic material, particularly in smaller populations. Genetic drift doesn't seem to occur in larger populations because there's no selective mating, and alleles are getting thrown around all the time. I heard somewhere that within the next 200 years or so, blondes will disappear because it is a recessive allele. I think that's bull considering the large amount of people with blonde hair, and heterozygous brunettes, but no matter.\n\nThe effect of loss of biological diversity... well I guess that depends. In selective breeding of dogs, breeders notice that they can get good results within the first few generations. For example, if they want really big dobermans, they'll mate two big dobermans, and then mate their largest offspring with other large dogs. After several generations, they'll notice that they can't make the dogs any larger because there's no more variation in size. Because they've been artificially selected, the "big" genes are all that's left, and there's no chance for "bigger" genes because there's no gene flow. (Gene flow is just the introduction of new genes into a population)\n\nI hope that helped, it was a little messy and abbreviated because the concept is very complex.
647648
Diversity means to have a variety and difference, as opposed to being all the same. We can talk about a diversity of cultures, or a diversity of plant and animal life, or even a diversity of religions. It can be used in Biology, Sociology, ethnology or just in plain everyday conversation. We value the word because it helps to create a more interesting planet that is vital and teaming with life. We value diversity in society because it should lead to tolerance and an appreciation of other cultures.
886957
You’re probably asking yourself why we spent so much time on HWE since it never happens in the real world. Why did I spend time on this?\n\nIt provides us with a baseline or null model to assess the impacts of different factors (each eliminated by one of the assumptions)\n\nIE\nThe organism is diploid\nReproduction is sexual\nGenerations are non-overlapping\nMating is random\ndoes not allow inbreeding and assortative mating\nPopulation size is very large\nremoves sampling error (genetic drift)\nMigration is negligible\nMutation can be ignored\nNatural selection does not affect the allele in question