aspect of gender differences in humans, otherwise known as sexual dimorphism, it’s evolutionary history in our species, and some behavioral and societal trends that are associated with it. To accomplish this, I will begin by outlining the anatomical structures that are commonly used in measuring sexual dimorphism in our species. After establishing these criteria, I will expand upon the evolutionary history of sexual dimorphism in humans beginning with the anthropoids in the Oligocene and
A Closer Look at Lucy: Sexual Dimorphism and Speciation in Australopithecus In his peer-reviewed article, “Sexing fossils: a boy named Lucy?,” James Shreeve discusses, in detail, a study on sexual dimorphism and possible speciation in Australopithecines in Hadar, Ethiopia, based on the famous A. afarensis specimen, “Lucy.” In the article, “Lucy’s kind takes humanlike turn,” the author addresses sexual dimorphism and speculates on sex-based differences in behaviors in A. afarensis. The two articles
Sexual dimorphism can be defined as “morphological differences or varied appearances between males and females within the same species,” stated from Webster’s Dictionary. Anthropologists and primatologists study sexual dimorphism for various reasons depending upon, what information is trying to be uncovered. For example, a forensic anthropologist might use sexual dimorphism to try to nail down traits that will allow easier identification of a sex within skeletal and dental remains (Plavcan, 2001)
ago. The distinctive characteristics of A. afarensis were: a low forehead, a bony ridge over the eyes, a flat nose, no chin, more humanlike teeth, pelvis and leg bones resembled those of modern man. Females were smaller than males. Their sexual dimorphism was males:females; 1.5. A. afarensis was not as sexually dimorphic as gorillas, but more sexually dimorphic than humans or chimpanzees. A lot of scientists think that Australopithecus afarensis was partially adapted to climbing the trees, because
noticeably disparate in size between male and female. Earhart and Johnson (1970 p.260) believe that species that regularly attack and kill birds or mammals as large as themselves have the greatest dimorphism. The male is smaller, which is rather unusual in the animal kingdom. This is called Reverse Sexual Dimorphism (RSD). There are two prominent theories for small males and three varying hypothesis for the female raptor being bigger than the male, sometimes as much as half again as
Raccoon Report GENERAL OVERVIEW Raccoons (Procyon lotor) belong to the Procyonidae (those who came before the dogs’ family). This highly intelligent mammal has a rounded head with a short nose, small ears, and a sturdy body with minimum-length, thick, grayish brown fur. Raccoons are easily identified by a distinctive pattern of alternating black and yellowish white rings around a large bushy tail. They are also identified by a unique narrow black face mask with two white patches above the eyes
surrounding islands [16]. An article An unexpectedly long history of sexual selection in birds-of-paradise discusses the species phylogeny examining the various species of the family and how over time they have evolved separately (Martin Irestedt, Knud A Jonsson, Jon Fjeldsa, Les Christidis, and Per GP Erison, 2009). Each species of the Family has rare and unique physical and behavioral traits tied to sexual selection and sexual dimorphism. By way of analyzing a nuclear data set including cytochrome
reproductive success. Muscularity, sexual dimorphism (general size difference between sexes), male beards, penis size, calculated fat storage (in the breasts and hips for women), and co-parenting are adaptations in humans explained through sexual selection: specifically, through competition. Natural and Sexual Selection are competing and paralleling factors that define human evolution. While Natural Selection may define the necessity to impart certain genes, Sexual Selection quickly allows adaptations
major focus of evolutionary psychology. This paper seeks to explain why masculinity cannot be explained by sociology alone and will present evidence that certain male behavior such as aggression can be explained through evolutionary psychology and sexual selection. When considering the source of human behavior people often argue about how much human behavior is encoded genetically and how much is learned through interaction with society and the environment. This “nature versus nurture” debate arises
African H. erectus had a brain and brain case similar in size to previous hominins, however, smaller than “average” skulls were found showing that there were some African H. erectus with smaller skulls which may have been women (indicating sexual dimorphism) or children/youth, the skulls also had fairly large browridges with thin skull bones (typical of East African H. erectus, ve... ... middle of paper ... ...nce of much more use and variety of tools including those believed to be specifically
Comparing Melville's Moby Dick as a Man's Story and Naslund's Novel, Ahab's Wife as a Woman's Story Throughout my reading of Moby Dick and Ahab's Wife, I was disturbed by the fact that the most tempting way to situate the two novels in a relationship was to categorize them as "male" and "female." Moby Dick was, of course, the man's story and Ahab's Wife was its womanly counterpart. This comparison makes sense when you consider the gender of the authors, Melville and Naslund, the gender of their
"Persistent female choice for a particular male trait values should erode genitive variance in male traits and thereby remove the benefits of choice, yet choice persists” (Miller, Christine and Allen Moore). This phenomenon is know as the Lek Paradox and has puzzled scientists for many years. Throughout all species there has been abundant evidence showing continuous female choice of male traits, yet there is still no definite answer as to what allows for genetic variance to be maintained, and why
Introduction The phenomenon of impulse buying is becoming increasingly commonplace in developed countries. Our culture of consumption makes us less likely to resist temptation and consider the consequences before purchasing things. The impacts could be varied dramatically depended on where it takes place. For instance, the things that you purchase impulsively could be a bar of chocolate; however, it could also be a Louis Vuitton handbag and the consequences would be much severe. Hence, a lot of researchers
A psychological mechanism is defined as an adaptation of human behavior that evolved due to evolutionary pressures. This paper focuses on the psychological mechanism of human mating strategies and the evolution of mate preferences. There are several theories to explain how differences in male and female mating strategies developed. This paper explores the parental investment theory, male mating effort as well as the role of different adaptive problems faced by males and females. The traits that humans
Gender Differences and the Brain Brandon Moore LTCY 199 November 21, 2013 As we all know the brain is one of the most amazing mysteries in the world; there is a lot to be discovered. This topic hits home for me because most of my life I have always wanted to know how is the brain any different between men and women. From the very beginning of life boys and girls are already different. The common topic of discussion is which gender’s brain matures faster. People often hear that girls mature much
book Personality Psychology: Domains of Knowledge About Human Nature, men view pornography more often than women (d=.63). Men also desire more sexual partners, have more frequent sexual partners, and are more willing to accept offers of sex from a stranger (Hald & Hogh-Olesen, 2010). Evolutionarily, sex differences have relied on parental investment and sexual selection theory. The sex that invests less in offspring is less discriminatory in their selection of a mate. Because women have more of an obligatory
position, prestige, wealth and s... ... middle of paper ... ... good looks nature's ultimate survival strategy? , P.43 - 49, February 2000 - Grier, James W. and Theodore Burk. Biology of animal behavior: Reproductive behavior; Sexual reproduction and sexual selection. p. 318 - 358. 6th ed. 1984 Wm. C. Brown Communications, Inc. Iowa. - Perrett, D. I., May, K. A. & Yoshikawa, S. (1994). Facial shape and judgment of female attractiveness. Nature, 386, 239-242.. - Interview with Dr. Riyad
Three spined stickle back fishes are small fishes with a deep body with three spines in front of the dorsal fin and are therefore are named stickle back because if the spines on the dorsal fin. These fishes are brownish, green and pale or orange reddish on the underside and are about 6 cm in length. The breeding male fish usually has a red belly and blue eyes. The three spined stickleback fishes are found in Northern Asia, northern America and Europe and some parts of southern and central Europe
Sell, Hone, and Pound (2012) examined the importance of physical strength in shaping male psychology. Aggression and violence are fairly effective ways of winning conflict in the competition for resources between males, but can impose large costs on the loser of the conflict (Sell et al., 2012). The consequences of conflict would have put high pressure for the male brain to evolve ways of interpreting the odds of success, to determine when to avoid conflict or engage in aggressive and violent actions
According to Madden (2001), “processing speed is a fundamental property of the central nervous system.” However, what if one gender’s brain processing results in an advantage over the other because of better reaction times? Current studies show contradictory findings when reporting gender differences on reaction time tasks (Adam et al., 1999; Calvo, 2009; Lahtela et al., 1985). Reaction time is referred to as “the amount of time from the onset of the stimulus beginning and responding” (Draper et