Natural Selection
... Often the superficial sexual characteristics imply more essential ones - the probiscus, size and deepness of voice of elephant seals are probably all controlled by the same gene Some of these characteristics allow males to fight each other more effectively. But what about the ones that don’t help th ...
... Often the superficial sexual characteristics imply more essential ones - the probiscus, size and deepness of voice of elephant seals are probably all controlled by the same gene Some of these characteristics allow males to fight each other more effectively. But what about the ones that don’t help th ...
Sexual Selection II - University of Arizona | Ecology and Evolutionary
... If there is variation in a trait that affects ability to mate successfully, and that trait is heritable, then individuals with that trait will become more common over time. What are some of these “sexually-selected traits? ...
... If there is variation in a trait that affects ability to mate successfully, and that trait is heritable, then individuals with that trait will become more common over time. What are some of these “sexually-selected traits? ...
Gerontology - Michael Hoerger
... At birth, the average American male can expect to live to age 74.5; female ...
... At birth, the average American male can expect to live to age 74.5; female ...
Lecture Questions
... 4. The cost of sexual dimorphism to males must be offset by a greater benefit. Which of the following is the most important evolutionary benefit to these males? a. Win more male-male competitions b. Attract more females c. Leave more offspring d. Live longer ...
... 4. The cost of sexual dimorphism to males must be offset by a greater benefit. Which of the following is the most important evolutionary benefit to these males? a. Win more male-male competitions b. Attract more females c. Leave more offspring d. Live longer ...
Evolution - 4ubiology
... with large bills are able to crack the hard seeds Important because it forms distinctive forms within a population that may become isolated breeding populations with separate gene pools ...
... with large bills are able to crack the hard seeds Important because it forms distinctive forms within a population that may become isolated breeding populations with separate gene pools ...
Presentation7
... with large bills are able to crack the hard seeds Important because it forms distinctive forms within a population that may become isolated breeding populations with separate gene pools ...
... with large bills are able to crack the hard seeds Important because it forms distinctive forms within a population that may become isolated breeding populations with separate gene pools ...
Sexual Selection
... The boxes above the tips of the branches indicate which species have net-stance and which species have male courtship trembling. A colored box indicates the trait is present; an open box indicates the trait is absent. The two versions of the phylogeny show the two most likely scenarios for the evolu ...
... The boxes above the tips of the branches indicate which species have net-stance and which species have male courtship trembling. A colored box indicates the trait is present; an open box indicates the trait is absent. The two versions of the phylogeny show the two most likely scenarios for the evolu ...
PowerPoint 簡報
... captive settings, solicits mating with noncolony members. Once settled reverts to xenophobia and loses fat stores ...
... captive settings, solicits mating with noncolony members. Once settled reverts to xenophobia and loses fat stores ...
SexSeln - life.illinois.edu
... Extra credit question Sexual selection theory predicts that ___________ pipefish should compete with each other for access to mates, and that ___________ will be the choosy sex. ...
... Extra credit question Sexual selection theory predicts that ___________ pipefish should compete with each other for access to mates, and that ___________ will be the choosy sex. ...
Sexual Reproduction, Mating Systems and Parenting
... example, many birds become sexually active when days get significantly long. Social-Hormonal Interactions Being near others may initiate mating behavior. For example, when a male ring dove is present, a female’s progesterone level increases, which then leads to courtship behavior. Also being near fe ...
... example, many birds become sexually active when days get significantly long. Social-Hormonal Interactions Being near others may initiate mating behavior. For example, when a male ring dove is present, a female’s progesterone level increases, which then leads to courtship behavior. Also being near fe ...
Sexual Selection and Human Reproductive behaviour
... Sexual Selection is an evolutionary process and there are two types; intersexual-selection (competition within members of the same sex) and intrasexual selection (selection between the sexes where the partner preferences for one sex determines the areas in which the other sex must compete). Sexual s ...
... Sexual Selection is an evolutionary process and there are two types; intersexual-selection (competition within members of the same sex) and intrasexual selection (selection between the sexes where the partner preferences for one sex determines the areas in which the other sex must compete). Sexual s ...
Sexual Selection
... Fisher’s Runaway process • If females exhibit preference for a male trait • And selection does not act on females • Then their sons and daughters will carry genes for both the preference and the trait • This creates a genetic correlation between the preference and trait • And leads to geometric inc ...
... Fisher’s Runaway process • If females exhibit preference for a male trait • And selection does not act on females • Then their sons and daughters will carry genes for both the preference and the trait • This creates a genetic correlation between the preference and trait • And leads to geometric inc ...
Sexual selection
... female preference for that trait • Female increases her fitness (= no. of grandchildren) disproportionately by producing attractive sons • Male trait and female preference lead to assortative mating • A genetic correlation between the male trait and female preference is ...
... female preference for that trait • Female increases her fitness (= no. of grandchildren) disproportionately by producing attractive sons • Male trait and female preference lead to assortative mating • A genetic correlation between the male trait and female preference is ...
Evolution study guide
... Descent with modification-how modern species arose over time, from earlier life forms Artificial selection- wild mustard Lamarck’s idea-acquire a trait in ones lifetime because of need & pass that trait to offspring ...
... Descent with modification-how modern species arose over time, from earlier life forms Artificial selection- wild mustard Lamarck’s idea-acquire a trait in ones lifetime because of need & pass that trait to offspring ...
Chapter 7 Questions
... Ex: The black peppered moths were scarce before the industrial revolution since they could be spotted easily by the predators. After the industrial revolution, however, the white peppered moths became scarce because they could be spotted easily in the smoke. There are very few intermediate moths. S ...
... Ex: The black peppered moths were scarce before the industrial revolution since they could be spotted easily by the predators. After the industrial revolution, however, the white peppered moths became scarce because they could be spotted easily in the smoke. There are very few intermediate moths. S ...
Exam II Vocabulary Review
... PART I Match the terms with their corresponding definition. A. B. C. D. E. F. G. H. ...
... PART I Match the terms with their corresponding definition. A. B. C. D. E. F. G. H. ...
lecture7a.html
... ”Now here, you see, it takes all the running you can do to keep in the same place.” ...
... ”Now here, you see, it takes all the running you can do to keep in the same place.” ...
PowerPoint Presentation - Sexual Selection (I)
... QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. ...
... QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. ...
10sexselect1student - Fort Hays State University
... Darwin’s attempt to explain evolution of characters, especially in male animals, that are: but that: “ depends, not on a struggle for existence, but on a struggle between the [males] for possession for the [females]; the result is not death to the unsuccessful competitors, but few or no offspring.” ...
... Darwin’s attempt to explain evolution of characters, especially in male animals, that are: but that: “ depends, not on a struggle for existence, but on a struggle between the [males] for possession for the [females]; the result is not death to the unsuccessful competitors, but few or no offspring.” ...
Sexual selection
Sexual selection is a mode of natural selection where typically members of one gender choose mates of the other gender to mate with, called intersexual selection, and where females normally do the choosing, and competition between members of the same gender to sexually reproduce with members of the opposite sex, called intrasexual selection. These two forms of selection mean that some individuals have better reproductive success than others within a population either from being sexier or preferring sexier partners to produce offspring. For instance in the breeding season sexual selection in frogs occurs with the males first gathering at the water's edge and croaking. The females then arrive and choose the males with the deepest croaks and best territories. Generalizing, males benefit from frequent mating and monopolizing access to a group of fertile females. Females have a limited number of offspring they can have and they maximize the return on the energy they invest in reproduction.First articulated by Charles Darwin who described it as driving speciation and that many organisms had evolved features whose function was deleterious to their individual survival, and then developed by Ronald Fisher in the early 20th century. Sexual selection can lead typically males to extreme efforts to demonstrate their fitness to be chosen by females, producing secondary sexual characteristics, such as ornate bird tails like the peacock plumage, or the antlers of deer, or the manes of lions, caused by a positive feedback mechanism known as a Fisherian runaway, where the passing on of the desire for a trait in one sex is as important as having the trait in the other sex in producing the runaway effect. Although the sexy son hypothesis indicates that females would prefer male sons, Fisher's principle explains why the sex ratio is 1:1 almost without exception. Sexual selection is also found in plants and fungi.The maintenance of sexual reproduction in a highly competitive world has long been one of the major mysteries of biology given that asexual reproduction can reproduce much more quickly as 50% of offspring are not males, unable to produce offspring themselves. However, research published in 2015 indicates that sexual selection can explain the persistence of sexual reproduction.