Polyandry Research Paper

Reproductive monogamy is defined as an exclusive sexual relationship between a female and a male based on their sexual interactions. Social Monogamy refers to male and female’s social living arrangement without sexual interactions. It refers to the living patterns, raising offsprings, and obtaining food. Monogamy is common in birds, but also occurs in invertebrates. Why would a male mammal choose to mate with one female when he can mate with more than one? Why would the male stay around instead of finding another female to live with? Many researchers have attempted to answer this question of why some mammals prefer monogamy over polygamy. Vole rats, one of the species that perform monogamous mating, demonstrate pair boding. Male and female pairs of vole rats have been observed together over several months, and the males stay with females even when the female is not reproductively active. A typical vole family in the wild is almost always consisted of one male, one female, and their offspring. In addition, unlike other species in which females are the only ones taking care of the offspring, vole rats share parental roles and even build nests together. Because they show these monogamous behaviors, they have served as a good species/model to learn about monogamy for neuroscientists. In this paper, monogamy, specifically in vole rats, will be explained along with its proximate and ultimate causes of this adaptation.

Results showed that clutch temperatures were relatively stable throughout the day, and that certain temperatures were, indeed correlated with observed offspring sexes. Though this study tested the American crocodile, Crocodylus acutus, it provides evidence of a correlation between egg temperature and the resulting sex of offspring. Charruau also presented an important point about global warming possibly posing a threat to the ratio of female to male offspring being produced in the near future, due to the fact that alligator sexing is based solely on environmental temperatures. These disrupted ratios could ultimately lead to the extinction of certain species, which are dependent on this mode of sex

In insect species with indirect sperm transfer, sperm is packed in a spermatophore that is either externally attached to the female 's genital opening or introduced into her bursa copulatrix. Sperm transfer is not immediate in these species, and consequently mate guarding has been suggested to function as a mechanism of guarding sperm until it is released from the spermatophore into the female (i.e. spermatophore guarding). Spermatophore guarding is relatively common in insect species with external spermatophores (e.g. Orthoptera; Alcock 1994; Simmons 2001), but supposedly absent in species with internal spermatophores and rapid sperm release (Simmons 2001). This study focuses on two hypothesis associated with mate guarding a tactic of many species that adjust their reproductive behaviour according to the apparent risk of sperm competition. The phenomenon of mate guard to consider sperm competition levels and evolution of internal spermatophore guard is wide spread in insects and other animals. We analyse two hypothesis one the rival exclusion followed by the next spermatophore renewal hypothesis. Results showed that as rival was introduced to the arena of mating of the distinctive original male (guard) in many cases showed a strong aggressive behaviour regardless of whether successively avert the rival. In the second hypothesis certainly majority of the incidents showed an attempt of

The main idea of Road salt can change sex ratios in frog populations was that road salt put down on roads to melt snow, can impact the sex ratios of frogs. The researchers found that the proportions of female in tadpoles were reduced down 10 percent when exposed to road salts. This suggest that road salt may have a masculinizing effect of frogs. For the experiment researchers used a 500 litter tank containing various levels of road salt to leaf litters from maple and oak trees. The scientist observed the sex ratio for the oak leaf litter without salt was female-biased 63 percent. But, when the salt was added the female portion of frogs decrease by 10 percent. The scientist also noticed that the oak leaf litter female tadpoles were larger

There are many methods of reproduction, but the two main methods are sexual and asexual, but which one is more efficient or beneficial. Sexual reproduction is the fusing of two gametes to produce an offspring. This form of reproduction is used by a lot of organisms, including us. Asexual reproduction is reproduction that only involves one parent. (“Pros and cons of sexual and asexual reproduction”). I am going to focus on asexual reproduction and the Desert Grassland Whiptail Lizard. This unique lizard uses asexual reproduction. Asexual reproduction is better for this species of lizards because it only requires one parent, it is less risky, and the population is only female.

Accepted animal mating theory suggests that females tend to select more “attractive” males as their breeding partners. In the case of Túngara frogs from Central America, male “attractiveness” is generally dictated by vocal ability and the size of their vocal sacs. However, a new study reveals that all hope is not lost for males with less desirable songs, thanks to the “decoy” effect.

Ecological isolation. Individuals mate in their preferred habitat, and therefore do not meet individuals of other species with different ecological preferences.

A nuclear family is a married couple with unmarried children living together. The traditional nuclear family is the best with the dad as the breadwinner, homemaker mom and children. An example would be the Obama’s. The extended family is family in which relatives also live in with the parents and children. Extended family usually includes your grandparents, aunts, uncle’s etc. monogamy is a form of marriage in which one woman and one man are married only to each other and a great example would be my mom and dad. Serial monogamy is having multiple spouses in his/her lifetime, but only one spouse at a time. It’s about finding the “one” the “right one” like Johnson stated (July 15). An example would be the TV show the bachelor. Serial monogamy became popular when marriage is popular.

The kinship chart that I drew, which represents my family, is very different from a Tibetan family. For a Tibetan family, it is highly common for brothers to share a wife. This is known as fraternal polyandry. The article “When Brothers Share a Wife” by Melvyn Goldstein describes the way fraternal polyandry works. Two or more brothers marry the same woman, live together and work together to help the family function. Polyandry is common because it helps all the brothers secure a better life, compared to if they were all living separately and were married to different women. In polyandry, it is usually ideal for the oldest brother to be the more authoritative one among the brothers. The wife has to treat all the brothers equally, and all the

Even through marriage is a universal human trait, the types of marriages vary across different cultures. Among the different types of marriages are monogamy, polygyny, and polyandry.

The alligator mating ritual is often called "water dancing." The animals ' underwater mating bellows are so forceful and low that they cause water droplets to fly up into the air, attracting potential mates. Alligators also use these noises to establish territorial dominance and intimidate other animals. Alligators breed in the Spring (April to May). A month after the noisy mating rituals and coupling, the female lays up to 50 eggs in a large (three feet tall and six feet wide) nest she constructed of mud, leaves and twigs on dry ground. The rotting vegetation in the nest warms the eggs. The temperature of the nest determines the sex of the hatchlings. If the eggs are incubated over 93 degrees Fahrenheit (34 degrees Celsius), the embryo develops as a male; temperatures below 86 degrees Fahrenheit (30 degrees Celsius) result in female embryos,

The lizard gave virgin birth to 11 eggs, but only 8 seem to be developing normally. They were in different Zoos, at the time researchers speculate that the giant lizards could of change from sexual to asexualreproduction, they found the way to clone themselves without a male. After this was documented, scientists reported about the snakes. Reports show that reptiles can hold on to sperm for several years, so initially researchers considered that the lizard’s eggs had a father. After this happened scientifics recommended that the species should not be isolated, they started to be afraid that they will start to clone

The last unit in the Principles of Biology II, taught by Professor Schneider-Paolantonio, focused on Ecology and the effects of human interference on the environment and its organisms. During recitation, we examined the effects of atrazine, a pesticide, on African clawed frog populations. Atrazine is the most commonly dispersed pesticide in the world, and contaminate ground and surface water that spreads through other habitats. Atrazine caused the genetically male frogs to become demasculinized and to mature as feminized adults. While their chromosomes (ZZ) stayed the same, their outward anatomy changed to a female’s. In the experiment, they found that the transformed frogs could mate with other males to produce offspring that are all genetically

    Frogs have two gonads attached to the kidneys. The sperm enters the urinogenital duct. The urinogenital duct connects the gonads to the cloaca. For females the eggs enter the oviduct and then into the uterus. The uterus is also connected to the cloaca. Once the eggs or sperm enter the cloaca they are then released to the outside environment.

The ancestral reproductive mode in lizards is oviparity, or egg-laying. In these species, embryos develop to some degree within the uterus but are then deposited into the environment, surrounded by a shell or shell membrane. These embryos receive nutrients through a yolk contained within the shell, in a process called “lecithotrophy” (Blackburn 1995). Egg-laying is generally cost-effective, because females need to carry the young in the oviduct only until the eggshells are sufficiently formed around the embryos (Andrews and Mathies 2000). Most squamates deposit their eggs at around stage 30 in the described stages of reptilian embryonic