Sexual selection can trump natural selection to the point that sexual selection can cause an organism to go extinct. How is this consistent with evolution??? Sexual selection sometimes generates features that may help cause a species' extinction, as has been suggested for the giant antlers of the Irish elk (Megaloceros giganteus) that became extinct in Pleistocene Europe Gould, Stephen J. (1974). "Origin and Function of 'Bizarre' Structures - Antler Size and Skull Size in 'Irish Elk', Megaloceros giganteus". Evolution 28 (2): 191220
sexual selection is natural selection, not sure what you saying evolution doesn't always favor the strong..... especially when there are no predators to thin the heard... [video=youtube;unoMMru4-c0]https://www.youtube.com/watch?v=unoMMru4-c0[/video] .
sexual selection IS natural selection. species choose mates that live longer, are more advantageous, are stronger, hardier
Often times thats true, females often select sexually dimorphic traits in males that are advantageous and improve that organism's fitness. However, it's not always true. Due to their sometimes greatly exaggerated nature, secondary sexual characteristics can prove to be a hindrance to an animal, thereby lowering its chances of survival. For example, the large antlers of a moose are bulky and heavy and slow the creature's flight from predators; they also can become entangled in low-hanging tree branches and shrubs, and undoubtedly have led to the demise of many individuals. Bright colourations and showy ornamenations, such as those seen in many male birds, in addition to capturing the eyes of females, also attract the attention of predators. Some of these traits also represent energetically costly investments for the animals that bear them. Because traits held to be due to sexual selection often conflict with the survival fitness of the individual, the question then arises as to why, in nature, in which survival of the fittest is considered the rule of thumb, such apparent liabilities are allowed to persist
I think your example would say the survival of the fittest was not the large antlers folks you speak of
Genetic changes in species aren’t simple, individual switches that have unique, isolated effects. Actual physiological differences will typically be influenced by changes in combinations of multiple genes and those combinations of elements of them with have other, often entirely unrelated effects too. Similarly, any given physiological change is likely to have more than one direct or indirect consequence. All of this is before we get in to outside influences such as environmental impacts, changes in related species (predators or prey for example) or changes in other individuals of the same species. It’s always worth remembering that evolution isn’t a conscious process with any aim or intention, it’s merely the inevitable consequence of natural processes. There’s nothing to say that all evolutionary processes will increase the chances of a given species surviving.
I think I understand what the OP is talking about. What is happening is that some species the females have sex with a male and the male then has no other role. The female can choose which male to mate with. She would want one that is healthy so will demand evidence of this. This will be in deer the males with the biggest antlers. In birds, such as peacocks it would be a great display of feathers. Only the male has this characteristic. It does not matter that many of them get killed for various reasons, the females will live and males that live will contain examples that show how healthy they are.
