I'm talking about marriage here. In some species, humans being one, but I'm also talking about albatrosses and the like - pairs mate for life. Is there a benefit to the organism itself in pairing for life - because sexual reproduction works best when you mix your genes with as many organisms as possible to spread them far and wide. If you limit yourself to one partner, surely that limits the spread of your genes.
216069
Spreading genes can be accomplished in more ways than one.  The actual problem is how to reproduce and rear as many offspring as possible given the time and resources available.  Albatross chicks (to use your example) are reared under difficult conditions requiring the cooperation of two parents; a strong pair-bond assists in making this possible.  Human children take many years to grow up; a strong pair-bond between their parents helps to ensure the survival of more children than might otherwise be able to make it. \n\nMonogamy, therefore, is beneficial not just to males (who get regular sex and the emotional satisfaction of the pair-bond), or to females (who get protection and assistance in the rearing of their children), but especially to the children who get a more stable and successful start to their lives than they otherwise might.  This, in turn, ensures the survival of the species.
480941
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
439888
An existing organism is born with certain genes.  Those genes determine how that organism will develop during its life.  Those genes cannot change ... there is no mechanism in life to alter the genes for the entire organism (individual cells yes ... e.g. cancer, but not the entire organism).\n\nSo even if that single organism lived for centuries (like a redwood tree), it cannot change (evolve) in ways not dictated by its genes.\n\nNew life (offspring) is a brand new set of genes ... a new mixture from each of its parents.  \n\nSo each offspring can be different from either one of its parents ... better or worse in some characteristics, or all characteristics, from either parent.\n\nSo over the entire group of individuals in a species ... you have many individuals with slight improvements over their parents.  Those will produce more offspring than those who have fewer improvements (or are slightly worse adapted) than their parents.\n\nThe result is evolution.  Many many tiny improvements in genes, over many many generations.  You cannot have that evolution, without the opportunity for new genes with every new life.
449527
I'm not going to write your paper for you - but I could give you some useful pointers. \n\n1. Before the spread of the gene there mating rituals would have relied on primative mechanisms\n\n2. The gene's presence allows more complex communication to be develop between the sexes\n\n3. There is a selective advantage in chosing a mate that has this gene as they are better able to express themselves, meaning they get their way more\n\n4. As breeding becomes aligned with those who have the communication gene pairs are able to discriminate more widely when looking for partners,
207705
Not all animals have multiple partners.many have the same one year after year.to reproduce. However most of the animals just mate to reproduce and that's all. they just don't go having sex with every species of their kind just have sex,like us wonderful humans tend to do.for animals it's not about how many chicks they can get "laid" by.It's only to keep their species in existence..
368587
I think it works both ways, we are all attracted to "types", but that doesn't mean who you marry fits that mold.  There's a big difference to what you're attracted to and what you're committed to.\n\nHere's an anecdote from nature.  Certain animals and plants have features that "attract" their prey, but that doesn't mean it works out to the preys' liking.  And it's not the only thing they find enjoyable.
274581
The different lifespans of different plants and animals, including humans raises the question of why these lifespans are found.\n\nThe evolutionary theory is that organisms that are able by virtue of their defenses or lifestyle to live for long periods whilst avoiding accidents, disease, predation etc. are likely to have genes that code for slow aging- good repair.\n\nThis is so because if a change to the organism (for example a bird might evolve stronger wings) may mean that it is exceptionally capable of escaping from predation, then it will live longer, and die of old age. So a member of the population with the better wings who by chance has genes that code for better repair will outlast its contemporaries and have more successors. Its genes will tend to dominate more and more of the gene pool and genes for slower aging and slower reproduction rate will dominate.\n\nConversely a change to the environment that means that organisms die younger from a common disease will mean that organisms that have genes that code for putting more energy into reproduction than repair will do better.\n\nThe support for this theory includes the fact that better defended animals, for example cats, live longer and functionally age slower than less well defended animals such as dogs; and even small birds that can fly away from danger live for a decade or more whereas mice which cannot, die of old age in a year or two. Turtles are very well defended indeed and live for over a hundred years.
484215
Several classic features characterize monogamy. In a monogamous relationship, a breeding pair shares the same nest and territory where they are frequently in contact. Monogamous males participate in parental care, and intruders of either sex are rejected \n\nBiologists believe that monogamy evolved in those species whose fathers could help rear the offspring (e.g., birds). Birds seem to have some of the longest relationships (over 90%). but take penguins for instance, No species of penguin truly mates for life. There are some "divorces" each year. The divorce rate varies widely between the different species. Generally the divorce rate is lowest (at around 10%) in those species with the shortest breeding seasons (such as the Adelie) - this is probably a good tactic as they don't have to waste time finding a compatible partner each season.  Conversely, penguins with a long breeding season (such as Africans) tend to have much higher divorce rates - as high as 60% in some reports. \n\nScientists think that macaws mate for life, producing one to three young each year. The young are relatively slow to develop, remaining in the nest for up to four months, and staying with their parents until the next breeding season.\n\nCanada geese and swans do mate for life. Mated pairs not only raise and protect their young together, but also look out for one another over the course of their lives. One mate will stay by the other's side if injured or dying, even if the rest of the flock is moving on. They are extremely devoted to one another. \n\nThe theory that monogamy originated from an equal partnership in "child-rearing" explains why only a small percentage (approximately three-percent) of mammals are monogamous. In mammals, females alone produce milk for the young. The percentage of primates that are monogamous (15%) is higher than most other mammals - who practice either promiscuity or polygyny.
406243
Species have NOT evolved to die.  The more accurate phrasing is that they have not evolved to live indefinately.  After reproduction, and the passing on of genetic material, Selection can no longer exert any pressure on a population.  This means that a species cannot evolve a longer life span unless there is some environmental pressure which causes reproduction to occur later, thereby selecting those individuals who can both survive, and remain fertile until such a time.  Actually, since reproduction is the defining event, some think that populations may actually enrich with genes which cause enhanced function in early life, but are detrimental later, eg. increased calcium deposition in bones.  Its called antagonistic pleiotropy.  \n\nRecent research on yeast has found genes which are regulated by metabolism, and can sense a dearth of nutrition.  When they do, they cause changes which allow the yeast to extend both their life and fertility until conditions improve.  So you can see that there are some ways in which selection can yield a longer life span.
41538
There are several.  One is the fact that plants and animals can be categorized.  If the had evolved, there would be no breaking point between various species.  There would be people with various ape-like characteristics.  The truth is that reproduction is limited to animals within groups.  A horse and donkey can make a mule (which cannot reproduce), but a dog and cat have different genetics which prevent reproduction between them.\nThere is also the problem of galaxies which all still act in clusters (gravitational attraction).  Calculating the escape speed based upon rate at which they are moving apart and masses of galaxies involved, the upper limit of 1 millions years for their existance is reached.  Evolutionists attempt to bypass this by stating that most matter in galaxies is invisible...the mass is only 10% of that needed to maintain the integrety of these systems.\nThe volume of meteoric dust on the moon was far less than NASA expected, prompting the first men on the moon to say, "I can see the soles of my shoes".
163199
Obviously you dont know how things work.\n\nCheck this out, a fish cannot give birth to a different species fish. What if a mutation occurs and the fish has a extra fin? Due to natural selection that fish is better suited to the environment, and mates more and the mutation becomes more often, vwooleh, we have a new species of fish assuming the other just pure breeds or it has migrated away.\n\nWe all started very basic, that basic thing mutates and mutates into say 10 basic things, those basic things become more complex and so those 10 basic things multiply into 100 more complex things each only breeding within its own mutation.
216046
The "Red Queen " theory of why there is sexual reproduction, states that organisms sexually reproduce to vary the immune response to ever changing bacterial and viral evolution, weather natural or artificial selection. You see the asexual organism having great reproductive numbers, this makes vulnerable populations to parasitical attack, hence they clone rapidly. There is also the genetic recombination component that other answers to your question brought up.
104335
First off we need the definition of symbiosis:\nThe intimate living together of two dissimilar organisms in a mutually beneficial relationship.\n\nBased on that definition, there are no symbiotic relationships between these marine mammals and other species. Among a pod (group) of the same species, they exhibit a complex hierarchy and will each take on specific tasks for the greater good of the pod. These dolphins spend their life cruising open waters, eating fish and mating. They do not provide any symbiotic relationship to other species.\n\nYou might argue that a pod of dolphins feeding may benefit some marine birds due to the fact they bring fish up to the surface, but that is a one way street, the birds do little for the dolphins.
277821
I don't think so. homogeneous populations are more vulnerable to diseases. This is because large numbers of the population share the same genes. The more diversified the gene pool the better the chances of survival. That's one of the reasons people reproduce sexually as opposed to asexually. So spread those genes around. :)
485140
True, in fact observations that the offspring from parents of different species (where offspring are possible) are sterile was one of the key lines of evidence that lead Darwin to evolution by natural selection. ie. that once two populations of the same species become different enough, they can't interbreed thus stay separate.  \n\nIt is now established though, through many observations, that bacteria have and do pick up chunks of DNA from unrelated species of bacteria. A lot of their DNA is very mobile. I guess it depends on what you call 'kind'.
185082
I would have to answer that you're asking the wrong question!  \n\nThe explanation of how a plant or animal can develop asexual reproduction isn't going to help you better understand incremental changes via evolution; what you really need to understand is how a plant or animal can develop sexual reproduction. \n\nLooking at the first, microbiological life, asexual reproduction - i.e. cell division or 'budding' -  was the first and most essential form of reproduction. It took century upon century for more complex life to develop and specialize; and, for the mechanisms of sexual reproduction to develop and become established. \n\nThe change from asexual to sexual reproduction would indeed have been  massive, but it doesn't follow that it had to be sudden. When scientists look at species and evolution, they will generally say that one species was more successful at adapting to their environment than another. \n\nIt seems that the ancestors of many plants and animals developed sexual reproduction mechanisms, and they were more successful in competing with other animals for food/territory, over an extended period of time. The less successful ones died out long ago.\n\nSo - it may not be totally accurate to say, "reproduction either works or it doesn't." A better statement would be, "evolutionarily speaking, changes in species over time may cause one method of reproduction to become less successful than another."  \n\nHaving said that: there are other scientists who agree that evolution isn't always slow and gradual; they argue that sometimes evolution happens occasionally in a sudden and dramatic way, when one species splits to become new species - generally the new species are created when one population becomes separated by geographic boundaries. \n\nI'd strongly suggest reading the Wikipedia article (linked below) on Stephen Jay Gould for an evolutionary point of view which counters the slow evolution methodologies advocated by Dawkins; as well as the articple on evolution itself - which looks at the development of the understanding of evolutionary principles and their historical context.
281667
The mind is a model of the world, which provides immense survival benefits. From recognising food to dangerous situations, any improvement to the model results in a little bit more survival, so the genes for a mind will propagate. \n\nTravus: Your model of conflict in evolution is too simple. There are plenty of situations where evolution will lead to co-operation, because individuals who try to "cheat" and game the system will actually be punished. Look up the Prisoner's Dilemma, and Evolutionary Stable Strategies.\n\nBesides, ideas do evolve - otherwise our science books would say the same as they did 500 years ago. What I suspect you meant was "I can't think of a good way that the capacity to have ideas evolved", which is a non-argument; if you wish to state that something cannot possibly have evolved, you must have a pretty solid reason for making that assertion.\n\nThe statement "striving to evolve further", also shows an unclearness of thinking. What is "striving to evolve"? Individuals certainly aren't, they have the genes they have and can't change them. Mutating them on purpose to attempt to evolve would be in most cases evolutionary suicide. The genes aren't "striving to evolve", either, partly because they have no mind to think about the striving, and partly because evolving from a gene's point of view means being replaced by another gene, which means elimination. Of course, if a gene were to start inhabiting bodies where the *other* genes were better, that would be beneficial to that gene. Evolution is a passive, undirected process - it is the inevitable result of a small proportion of mutations being favourable. Words like "striving" confuse the issue. There is no target, no goal just off in the distance somewhere, just what reproduces and what doesn't.\n\nLove is simply another method the mental model uses to ensure the survival of the genes. Within families, there are good genetic reasons to love your blood relations - they share some of your genes. For example, on average, a brother or sister will share half your genes. So, giving them food, for example, will provide your genes half the benefit you would gain from eating it yourself. If they are younger, and you are pretty full, such that eating it yourself will provide little benefit, feeding them instead will provide more benefit to your genes.\n\nOf course, there's a lot more to it than this - evolution rarely provides soundbite answers - but looking into ethology should explain what you want to know.