Ms. Carmelitano

Bellringer eys/disgust/ eys/disgust/ Write down your ratings

Evolution Darwin Theory of natural selection Species acquire adaptive characteristics to survive in an ever- changing environment

Theory of Natural Selection Those members of a species who have characteristics that are better suited to the environment will be more likely to breed They will pass these traits on to their offspring Darwin traveled to the Galapagos Islands and found Finches with different beaks depending on the island it was on. They were adapted for the food in that habitat

Evolution Over several generations, natural selection will cause the species to develop the characteristic, this is called adaptation. Darwin wrote his theory in “On the Origin of Species”

The Descent of Man Darwin’s book Laid foundation that biologists could study animals to get ideas about human behavior Mating, love of mother for offspring, self-preservation

Evolutionary Psychology Genes mutate, those that are advantageous are passed down through natural selection Evolutionary psychologists explain human behaviors as testimony to the development of our species over time

Curtis et al Carried out research on the internet to test disgust Online survey in which participants were shown 20 images, 7 of which were infectious or potentially harmful to the immune system and 7 which resembled them 77,000 people in 165 countries CULTURALLY SOUND Disgust reactions were strong for those pictures that threaten the immune system or resembled items that may threaten the immune system

Curtis Disgust decreased with age Women were more likely to be disgusted This supports the idea of disgust for reproduction

Problems Little is known about early human behavior so the conclusions are based on hypothesis (we cannot study if levels of disgust have changed over time) Underestimate the role of culture

Dan Fessler Carried out research on disgust Argued that the emotion of disgust allowed our ancestors to survive long enough to produce offspring Studied nausea in a woman’s first trimester of pregnancy Hormones lower the mother’s immune system to not fight the new genetic material in the womb Hypothesis: nausea helps to compensate for the suppressed immune system

Fessler’s Methods Tested healthy pregnant women and asked them to think about 32 different stomach-churning scenarios Walking barefoot and stepping on a earthworm Someone sticking a fishhook through their finger Maggots on meat Then asked questions to determine if the women were experiencing morning sickness Women in their first trimester scored higher than those in later terms (Meaning they had lower tolerance for disgusting scenarios) BUT most differences were only about food related questions

WHY? Many diseases are food born Our ancestors could not be picky about what they ate By increasing our pickiness it allowed those with sensitive stomachs to have more children Because pregnant women with lower immune systems were forced to avoid food which may have diseases in it

Activity Are you smarter than a chimp? Pre question – do you think that evolution has made humans “smarter” than chimps?” Post question – why do you think we have evolved in this way?

Tetsuro Matsuzawa (2007) Primate Study Kyoto University in Japan Aim: Examine spatial reasoning in young chimps vs humans Procedure: 1. Taught three pairs of chimps to recognize numbers 1-9 on a computer monitor 2. Sat chimps and humans in front of computer monitors 3. Numbers flashed up on the touch screen monitor in random spaces 4. The numbers were then replaced with blank squares The chimps and the humans were asked to recall remember where the numbers had appeared, touching on the squares in the correct order Findings: Dr. Matsuzawa found that the chimps had an easier time memorizing the number pattern This could be because chimps live in an environment where quick spatial reasoning skills are necessary for survival Humans do not rely on this as much, so they have not evolved in the same way