Day: April 8, 2021

making sure to include the question number.
1.What are primitive traits, and what is an example of a primitive trait that primates share? What are derived traits, and what is an example of a derived trait in humans? (use examples that are not in the textbook) What does it mean that primitive and derived traits are relative terms?
2.As the textbook states, “Primates are one of at least twenty Orders belonging to the Class Mammalia.” What are the characteristics that all mammals have in common? When thinking about these mammalian traits in primates, would they be considered primitive or derived traits? Explain your answer.
3.What are generalized traits, and what is a specific example seen in primates? What are specialized traits, and what is a specific example seen in primates? (use examples that are not in the textbook)
4.Describe the following characteristics of primates (from the textbook section “Primate Suite of Traits” and the slidecast):
Vision/forward-facing eyes/postorbital bar/trichromatic and dichromatic
Brain size/visual center/neocortex
Smell and evolutionary trade-offs
Arboreal/3D environment/pentadactyly
Opposable thumbs/toes and tactile pads
Life history
Behavioral and ecological traits
5.What is homodont v. heterodont dentition and what type of dentition do primates have? List and describe the tooth types found in the heterodont dentition. What is meant by the “dental” formula, and what is the dental formula of humans?
6.If a scientist found a primate jawbone, would they be able to determine if the jawbone had belonged to a male or a female primate? Explain your answer.
7.What do frugivores eat? Describe the characteristics of frugivorous primates. What do insectivores eat? Describe the characteristics of insectivorous primates. What do folivores eat? Describe the characteristics of folivorous primates.
8.List and describe the different activity patterns that are explained in your textbook. Which one would you say applies to humans and why?
9.Describe the different locomotor adaptations seen in primates (vertical clinging and leaping, quadrupedalism, brachiation, bipedalism). Briefly describe the skeletal adaptations associated with each of these locomotor patterns (except for bipedalism).
10.Explain why humans have evolved a biological craving for sugar and why this craving can be harmful in modern environments (from the article on sugar).

Millions and millions of years ago, apes survived on sugar-rich fruit. These animals evolved to like riper fruit because it had a higher sugar content than unripe fruit and therefore supplied more energy.

“Sugar is a deep, deep ancient craving,” said Daniel Lieberman, an evolutionary biologist at Harvard University and author of “The Story the Human Body: Evolution, Health, and Disease

And sugar offers more than just energy it helps us store fat, too.

When we eat table sugar, our bodies break this down into glucose and fructose. Importantly, fructose appears to activate processes in your body that make you want to hold on to fat, explains Richard Johnson, a professor in the department of medicine at the University of Colorado and author of “The Sugar Fix .” At a time when food was scarce and meals inconsistent hunting is significantly less reliable than a drive-through hanging on to fatwas an advantage, not a health risk.

In a forthcoming paper, Johnson postulates that our earliest ancestors went through a period of significant starvation 15 million years ago in a time of global cooling. “During that time,” he said, “a mutation occurred” that increased the apelike creatures’ sensitivity to fructose so that even small amounts were stored as fat. This adaptation was a survival mechanism: Eat fructose and decrease the likelihood you will starve to death.

The sweet taste was adaptive in other ways as well. In the brain, sugar stimulates the “feel-good” chemical dopamine. This euphoric response makes sense from an evolutionary perspective since our hunter-gatherer ancestors predisposed to “get hooked” on sugar probably had a better chance of survival (some scientists argue that sugar is an addictive drug

“Imagine if someone hated sugar in the Paleolithic era,” said Lieberman. “Then they wouldn’t eat enough sugar or have enough energy and wouldn’t have children.”

In other words, anything that made people more likely to eat sugar would also make them more likely to survive and pass along their genes.

All the food challenges our prehistoric ancestors faced mean that biologically, we have trained ourselves to crave sweets. The problem today is that humans have too much of the sweet stuff available to them.

“For millions of years, our cravings and digestive systems were exquisitely balanced because sugar was rare,” Lieberman wrote in an op-ed for The New York Times. “Apart from honey, most of the foods our hunter-gatherer ancestors ate were no sweeter than a carrot. The invention of farming made starchy foods more abundant, but it wasnt until very recently that technology made pure sugar bountiful.”

Weight gain was not a real risk when our instincts meant we might scarf down the nutritional equivalent of a carrot whenever we happened to stumble across one. Drinking soda all day the contemporary equivalent is a different story.

Today, the average sugar intake in the U.S. is 22 teaspoons per person per day, which is four times the amount that the World Health Organization suggests is healthy. Eating too much sugar is linked to a laundry list of negative health effects, including diabetes, obesity, and high blood pressure.

“We need to realize that our bodies are not adapted to the amount of sugar that we are pouring into them and it’s making us sick,” said Lieberman

Original Link: https://www.businessinsider.com/evolutionary-reason-we-love-sugar-2014-4?r=US&IR=T

You will be graded using the following rubric:

A  90-100%    Outstanding work with thorough, detailed, and clearly written answers