Is the human population in hardy Weinberg equilibrium?

Answer 1

The human population is not in Hardy-Weinberg equilibrium.

The Hardy-Weinberg theorem is an ideal principle in which the population of a species will remain constant only if the following five assumptions are true: 1 - random mating, 2- a large population size, 3 - no mutations, 4- no new alleles are introduced/lost, and 5 - no natural selection. If all of these assumptions are correct, then the population is in genetic balance, Hardy-Weinberg equilibrium; however, this is only an ideal situation because evolution is always occurring within populations.

Humans, for example, do not randomly mate: usually individuals choose a spouse who has positive attributes that they like, which may include: personality, taste, attractive, good with children, intelligence, sometimes race/color, sometimes height, humor, etc. So we have now disproved #1.

#3 - every human being, according to my Biology professor Donald Chandler, has at least 2 mutations. Most mutations are not harmful or don't make any real difference. Some can be very harmful; the point is that humans have mutations and thus #3 is broken.

#4 - New alleles are being introduced into the human gene pool from other human populations constantly - no one stays in their town and inbreeds with only their neighbors. We travel/marry people from other streets, towns, cities, states, countries, or at least our entire family is not made up of second cousins twice removed. Thus #4 has now been disproved as well.

#5 - natural selection occurs all of the time - People who carry inherited, life-threatening diseases may die before they can pass the gene for that disease to their offspring. With the help of modern medicine, this is now not as terrible as it used to be. People can be treated with proper medications for their genetic diseases. Women who in the 1800s would have died in childbirth due to being too small in the hip area to give birth can now have Caesarean sections (C-sections) and both mother and child can survive. Without modern medicine, natural selection would have been genetically in favor of women with larger hip areas for childbirth.

I skipped #2 because although there are billions and billions of humans in the world, I was not sure if an ideal population should have an infinite number of individuals. Either way, now you know all about how this Hardy-Weinberg theorem works - and how the ideal situation could never truly occur, even in Humans.