Sexual selection classified by Darwin. In humans, intersexual selection applies, involving members of one sex choose who they want to mate with from the opposite sex. Women choose partners and men compete. Sexy sons’ hypothesis: relates to inter sexual selection, showing women choose their partner depending on what features he has. She chooses the most desirable characteristics that her offspring might inherit.
Males had a larger canine size and bite force compared to females signifying their ability to feed efficiently , which is important for growth and survival and possibly mating success. Introduction The observable difference between males and females of the same species is called sexual dimorphism. Sexual dimorphism in size and morphology are is visible throughout the animal kingdom. Charles Darwin’s sexual selection hypothesis states that sexual dimorphism evolves when characters that have an advantage in either competition for mates or mate choice are selected for within one sex (Hendrick et al.,1989). However, it was noted that in some cases, sexual dimorphism could have evolved from food competition between sexes, or differences in the reproductive roles.
Sexual selection in Frogs (Anurans) Sexual selection is the process in which organisms compete to mate. Sexual selection has important implications for natural selection because the basis of natural selection is fitness or the ability of an organism to reproduce. The ability to mate is what guarantees an organism the passing of his genetic information to his offspring and insures that his genetic information is carried through future generations. Sexual selection therefore leads to secondary sexual characteristics that are a result of selection pressure when males compete. Different organisms have unique mechanisms when it comes to sexual selection, some species have combat (giraffe necking), some have extravagant ornamentation (peacock feathers), and some have complex courtship rituals (bees dancing).
Describe and Evaluate One Theory of Attachment and Consider its Significance on Child Rearing Today Bowlby (1951) was influenced by ethological studies that suggested infants were "genetically programmed to form attachments to a single caregiver within a critical time period." The critical time period described is called the "sensitive period," it is a period of time in which something is likely to occur. He suggested that "mother love in infancy is as important for mental health as vitamins and proteins are for physical health." Bowlby focused on the mother as the attachment figure. Bowlby argued that attachment was an "evolved mechanism;" an innate response that ensured the survival of the child.
Kangaroo Care offers a way for parents to have contact and interaction with their infant that is beneficial to mom, dad, and baby. It is encouraged for them to do skin to skin contact or Kangaroo Care as soon as the baby can tolerate it. This may aid in the infant survival and shorten the NICU stay. 2. Thesis: Research suggests that Kangaroo Care is beneficial for premature infants because it promotes bonding with parents and normalizes vital signs.
Darwin therefore suggested sexual selection stating that any characteristic that benefits reproductive success will become the norm over time as it is consistently selected. Sexual selection involves inter and intra sexual selection. Intra sexual selection is the evolutionary process in which members of one sex (usually males) compete with each other for members of the opposite sex. Those who win are able to pass on their genes, which include the factors that made the winning person successful. This helps to ensure the offspring’s survival whilst passing on successful genes.
Excitement The first phase is the excitement stage, by which an erection of the penis occurs in males and vaginal lubrication occurring in females. In this phase males erections can occur in 3to 8 seconds after sexual stimulation. The scrotal skin thickens becoming less baggy and the testes
Secondly, he suggests that infants are born with innate social releasers, such as crying and smiling, and that they also have cute faces to elicit care-giving. Besides this, Bowlby believed that there is a Critical period to form an attachment which is 2 ½ years. It is important that babies form attachment before this critical period as Bowlby said that, if this didn’t happen it will be much more difficult thereafter, and you will also be damaged for life; socially, emotionally, intellectually and physically. Furthermore, he suggested that a baby focuses its attention on one special person, which is the definition of monotropy. Bowlby claimed that infants need one special attachment relationship that is qualatively different from all others.
Children really need attachment figures that can provide care .Usually this would come in the form of a single care provider however there are certain circumstances were multiple attachments figures are needed in order to ensure basic survival. This would mean that evolutionary theory of attachment would be more applicable to Tina’s situation. As Tina would be too busy taking care of her child, she would not be able to buy herself the necessities needed to care for the baby as well as herself. This would mean that the father would have to be introduced into the relationship in order to ensure their basic future survival as the father may be able to provide these resources while the mother can
This theory may have something to do with the development of attachment because the baby is dependent on the caregiver to feed them, and without food the baby will not survive. Research leading to this theory showed that this is how animals develop attachments with their caregivers, and although we cannot be sure that these findings can be generalized to attachment in children, it does show that this appears to be the way which many animals will form an attachment with their caregivers, and a child is in a similar helpless position of a newly-born animal. Harlow had studied how monkeys were attached to their caregivers, by placing baby rhesus monkeys into cages, where there were two surrogate mothers, one made from a soft material, similar to a parent monkey, and the other was made from wire mesh and had a bottle attached to it. Harlow found that the monkeys spent most their time with the clothed monkey rather than the one which offered food. From this Harlow concluded that monkeys have an unlearned need for contact comfort.