Human Evolution
Austin Chiang
Mr. Holmes
AP Biology – Period 1A
24 November 2014
How is the Human Race Still Evolving Today? Evolution is the descent of organisms from common ancestors with the development of genetic and phenotypic changes over time that makes them more suited to the environment. However, with how advanced and dominant human society is compared to the rest of the world, many ponder whether evolution is still happening for the human race. We can see signs that we, as humans, are still evolving through the fact that we drink milk, we are losing our wisdom teeth, and our brains are shrinking. The first sign that humans are still evolving today is due to the fact that we are still drinking milk. Millions of years ago, the first Homo sapiens only drank milk from their mothers while they were infants. Once reaching an age of about 4 or 5, the body of the Homo sapien would begin to slow down the production of lactase in its body. Lactase is the enzyme that allows mammals to digest the lactose in milk. Any other milk drinking after the production of lactase slowed down resulted in things such as stomach cramps or diarrhea that was life threatening. Without the enzyme, lactase, the body is unable to digest lactose and it simply goes bad in the guts. However, thousands of years later, a genetic mutation occurred in a homo sapien that permanently jammed the lactase production, even after normal age, on. This would allow lactase to constantly be produced in the body and allow for drinking milk. As a result, the Homo sapien passed down the gene to his children, who would pass it down to their children, and so on. Eventually, many people that could drink milk for a lifetime appeared. Today, almost every person on the planet has the genetic mutation enabling them to drink milk for their entire life. Although some are still lactose intolerant, meaning they were not born with the gene, the ability to drink milk in today’s society is proof that humans are still evolving today.
Mr. Holmes
AP Biology – Period 1A
24 November 2014
How is the Human Race Still Evolving Today? Evolution is the descent of organisms from common ancestors with the development of genetic and phenotypic changes over time that makes them more suited to the environment. However, with how advanced and dominant human society is compared to the rest of the world, many ponder whether evolution is still happening for the human race. We can see signs that we, as humans, are still evolving through the fact that we drink milk, we are losing our wisdom teeth, and our brains are shrinking. The first sign that humans are still evolving today is due to the fact that we are still drinking milk. Millions of years ago, the first Homo sapiens only drank milk from their mothers while they were infants. Once reaching an age of about 4 or 5, the body of the Homo sapien would begin to slow down the production of lactase in its body. Lactase is the enzyme that allows mammals to digest the lactose in milk. Any other milk drinking after the production of lactase slowed down resulted in things such as stomach cramps or diarrhea that was life threatening. Without the enzyme, lactase, the body is unable to digest lactose and it simply goes bad in the guts. However, thousands of years later, a genetic mutation occurred in a homo sapien that permanently jammed the lactase production, even after normal age, on. This would allow lactase to constantly be produced in the body and allow for drinking milk. As a result, the Homo sapien passed down the gene to his children, who would pass it down to their children, and so on. Eventually, many people that could drink milk for a lifetime appeared. Today, almost every person on the planet has the genetic mutation enabling them to drink milk for their entire life. Although some are still lactose intolerant, meaning they were not born with the gene, the ability to drink milk in today’s society is proof that humans are still evolving today.