Biological Anthropology Ways in Which We Differ (and why that can matter)

App. 30 trillion RBC in the human body Red Blood Cells Heme: iron holding unit (need iron in our diet to produce new hemoglobin Globin: surrounding proteins Heme is part that combines with oxygen, picking it up in the lungs and taking it to tissues where there is less Oxygen Need oxygen to process food, energy production for activities 25 trillion red blood cells red cell is sack of hemoglobin normal cells are donut shape BUT: red cells do not reproduce (like brain cells) and they are made by stem cells in the bone marrow: does not even contain a nucleus ANEMIA: # of red blood cells falls below normal, not allowing enough O2 to body’s tissues..feeling tired and weak. Develop iron deficiency, B12 deficiency or low folic acid in the dit App. 30 trillion RBC in the human body you are both destroying (and making) new red blood cells at a rate of around 2.7 million cells per second. Every red blood cell contains about 270 million hemoglobin molecules, each one capable of carrying four oxygen molecules

Let’s Start Outside?

ABO Blood Group Alleles A B O Genotype AA, AO BB, BO OO AB Phenotype A codominant Selection against a heterozygote recessive

ABO Differences

Rh (Rhesus) Blood Group Alleles D d Genotype DD, Dd dd Phenotype Rh+ Rh- dominant Selection against a heterozygote recessive

Maternal/Infant Rh Incompatibility Rh+ and Rh - : Protein found common to everyone byt the Rd+ will have a few more AA linked in its chain

Now Let’s Go Inside…

App. 30 trillion RBC in the human body Red Blood Cells Heme: iron holding unit (need iron in our diet to produce new hemoglobin Globin: surrounding proteins Heme is part that combines with oxygen, picking it up in the lungs and taking it to tissues where there is less Oxygen Need oxygen to process food, energy production for activities 25 trillion red blood cells red cell is sack of hemoglobin normal cells are donut shape BUT: red cells do not reproduce (like brain cells) and they are made by stem cells in the bone marrow: does not even contain a nucleus ANEMIA: # of red blood cells falls below normal, not allowing enough O2 to body’s tissues..feeling tired and weak. Develop iron deficiency, B12 deficiency or low folic acid in the dit App. 30 trillion RBC in the human body you are both destroying (and making) new red blood cells at a rate of around 2.7 million cells per second. Every red blood cell contains about 270 million hemoglobin molecules, each one capable of carrying four oxygen molecules

Two Forms of Beta Hemoglobin Normal Hemoglobin (A) Mutated Hemoglobin (S) Inherited as a simple mendelian trait, the sickle-cell anemic inherits two variant (sickling) alleles, one from each parent. Individuals with one normal and one vaiant allele are generally healthy but are carriers, thus, have the sickle-cell trait…if two heterosygous carriers marry, the chances are one in four that a child will have sickle-cell anemia on sense strand in the sizth position codon Normal : codon codes for Gluatamic acid Hba: CTC…glutamic acid with mutation HBs: CAC…valine HBs behaves differently than Hba when O2 levels become low…HBs hemoglobin will change its physical shape, or sickle

Beta Hemoglobin Protein consists of 146 amino acids Gene consists of 438 bases (146 X 3) Protein comes in two forms

The “Normal” Situation (HbA allele) DNA: GGA CTC CTC TTT Codon #5 #6 #7 #8 Amino Acid #6 Glutamic Acid

The “Mutated” Situation (HbS allele) DNA: GGA CAC CTC TTT Codon #5 #6 #7 #8 Amino Acid #6 Valine

The Difference is in Codon #6 Normal allele: CTC Normal A.A.: Glutamic Acid Mutated allele: CAC Substituted A.A.: Valine Everything else is the same: 145 identical amino acids 437 identical DNA bases

Sickle-Cell Alleles HbA HbS Genotype HbA HbA Phenotype HbA HbS normal HbS HbS Phenotype normal dominant sickle-cell trait recessive Selection against a heterozygote sickle-cell anemia

Red Blood Cells ‘donut’ shaped sickle shaped

A simple mutation with multiple effects

Sickle-Cell in the U.S. Sickle cell anemia is the most common inherited blood disorder in the US More than 70,000 people have sickle cell disease Sickle cell disease occurs in 1 in every 500 African Americans About 8% of African Americans are carriers of sickle cell disease Two million people have sickle cell trait Approximately 1 in 12 African Americans has sickle cell trait

Balanced Polymorphism Situation in which selection maintains two or more phenotypes for a specific gene Selective mechanism

Heterozygote Advantage

What advantage could sickle-cell offer?

Malaria Infectious disease caused by Falciparum plasmodium Mosquito is carrier Malaria is passed through bacteria that live inside of mosquitoes known as the parasite falciparum plasmodium the mosquito is the vector or carrier of malaria

Malaria perhaps the most deadly organism in the world (to humans) 300-500 million people in the world 1-1.5 million people die each year

Malaria Parasite infects blood Part of life cycle occurs in red blood cells Population continuously infected

Distribution of Malaria

Distribution of the HbS allele

The Connection Heterozygote has greatest fitness in malarial environment Both high in frequency

Viruses Not alive Require host cell to reproduce Symptoms and effects relate to which host cells are used

Viruses Viruses use the cells genetic machinery to make new copies

Influenza A Virus Highly variable surface structures Mutates readily Avoidance behaviors frequent handwashing covering coughs having ill persons stay home, (except to seek medical care) minimize contact with others in the household who may be ill with swine-origin influenza virus. Model of the influenza A virus showing HA and NA receptors projecting from the surface of the virus. Source: http://www.udel.edu/chem/white/C647/FluVirus.GIF; accessed May 5, 2009.

H1N1 Virus

H1N1 Virus A “triple reassortment” virus consisting of human, avian, and swine influenzas Virus strains 90% identical to H1N1 have been circulating in swine for approximately 10 years Combination of viral strains thought to have arisen when live pigs were transported between North America and Eurasia Source: http://www.gate2biotech.com/origins-of-the-swine-flu-virus/; accessed on 24 Nov. 2009

HIV Virus HIV uses T-cells as hosts T-cells are part of the body’s immune system Infection can lead to AIDS

From HIV to AIDS HIV+ exposure to virus and antibody production CD4 (t-cell) count drops after infection, rebounds, then diminishes ≤ 200 = “AIDS” Acquired Immune Deficiency Syndrome

A global view of HIV infection 33 million people [30–36 million] living with HIV, 2007 2.2

Ebola Zaire Electron micrograph of Zaire Ebola virus. This is the first photo ever taken, on 10/13/1976 by Dr. F.A. Murphy, now at UC Davis, then at CDC. Diagnostic specimen in cell culture at 160,000 x magnification.

Ebola Zaire Majority of cases are lethal Animal Source? The virus’ genome consists of 18,959 nucleotide bases Animal Source?

Cumulative reported cases in Guinea, Liberia, and Sierra Leone provided in WHO situation reports beginning on March 24, 2014 through the most recent situation report on April 22, 2015. Source: http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/cumulative-cases-graphs.html; accessed 30/04/2015

Current Ebola Epidemic (as of 28 April 2015) Country Total Cases (Suspected, Probable, and Confirmed) Laboratory-Confirmed Cases Total Deaths Guinea 3584 3158 2377 Liberia* 10322 3151 4608 Sierra Leone 12371 8586 3899 Total 26277 14895 10884 Countries with Widespread Transmission Source: http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/case-counts.html, accessed 30 April 2015

Current Ebola Epidemic (as of 28 April 2015) Country Total Cases (Suspected, Probable, and Confirmed) Laboratory-Confirmed Cases Total Deaths Nigeria 20 19 8 Senegal 1 Spain United States 4 Mali 7 6 United Kingdom Total 35 33 15 Previously Affected Countries** Source: http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/case-counts.html, accessed 30 April 2015