Sexual reproduction

John Endler conducted two studies documenting the relationship between guppy coloration patterns in correlation to predation and sexual selection. Endler (1980) references his previous field study (Endler, 1978) in regards to coloration patterns present in the presence and absence of different predators. The relationship that was found there (Endler, 1978) was that in areas of high predation, coloring was less conspicuous and more closely blended to their background, whereas in areas of low…

All living organisms, including humans, reproduce to ensure the survival of their species. The male and female reproductive systems are essential for reproduction. The main purpose of the male reproductive system is to produce and deliver sperm into the female reproductive system. The main purpose of the female reproductive system is to produce egg cells and to nurture a fertilized egg so it is able to develop into a fetus. The male and female reproductive systems are distinct from one another…

of unprotected sexual intercourse. It is estimated that between 50 and 80 million couples of childbearing age are affected by infertility and although it does not present as a physical threat to the patient it carries along with it a socialized stigma. (Roupa, Puscheck, Mayo, Falcone) There are copious reasons that a couple could have trouble conceiving, but according…

baboons around, guarding them from other males and participating in frequent grooming and sexual mountings (Bercovitch 1983). Due to the fact that other male olive baboons often harass couples in consortship, often there is a large male turnover during a single female fertility period—thus their polyandrous behavior. Female baboons often consort with an average of three or four male baboons during one of their sexual cycles (Bercovitch, 1989). A male’s ability to consort with a female is…

that agrochemicals, which includes atrazine, have adverse effects on the reproductive systems of amphibians. One of the effects is a reduction in the number of follicles in amphibians, which shows that agrochemicals have a negative impact on the reproduction system of female amphibians (Katti et al, 2015). Unlike Katti et al (2015), Ji et al (2016) was worried about the impact atrazine had on early embryos. They were worried because it was shown that atrazine has an adverse effect on the…

A couple of weeks ago, Professor Baasten asked the class, “Do you want to have a child?” and followed up with, “Why?” The lecture went on, explaining the different reasons why people want to have children despite it being an irrational act, and he even allowed us to explain our own take as to why we wanted to have children. However, we then talked about when people are physically unable to have children – infertility. Many talk about how wonderful children are, yet some are not able to…

living organism is to continue its existence; there are two ways to accomplish this: Immortality or reproduction. Some marine animals, such as jellyfish, are capable of “cheating death” by reproducing asexually. But for humans, and most other forms of life, we achieve this feat through reproduction. This is a prodigious responsibility that I think many people do not truly consider before engaging in sexual intercourse. Every individual is responsible for his or her actions. If a woman is…

Because God always existed in reality and understanding, created the universe and things in the universe, God is also the Intelligent Designer (will use Creator as a shorter term). If something exists, it has an intended purpose because it was created by God, who neither requires or needs a purpose to exist nor to have a purpose for things to exist. All things that exist or will exist in the universe were created by God for a puipose. Whether a specific or undefined purpose is irrelevant to…

can be controlled by either the inheritance of sex chromosomes or environmental conditions. In many organisms, the sex of a developing embryo is determined by the inheritance of sex chromosomes that contain genetic information which determine the sexual phenotype in the developing embryo (Hurney et al. 2016). The sex determination of humans is determined by chromosomal inheritance. Humans have two sex chromosomes, X and Y; a human embryo will develop into a male if the embryo inherits an X…

Unlike the modern definition of friends with benefits, friends with benefits have many forms of friendships and the benefits are more than just sex. From a reciprocal altruism point of view: reproductive and survival costs and benefits of opposite-sex and same sex friendships can be observed in humans. As our ancestors have lived in the past, without friendship certain tasks or social life would be difficult because a friend can provide fitness relevant benefits to us in several ways such as…