We are unique Skin, eye, hair color Environment Food Clothing Language

How did we become so unique? 1) Sexual reproduction 2) Independent assortment of chromosomes (from mom and dad) 3) Random fertilization of gametes (random egg + random sperm) IT’S IN OUR DNA! Nicastro, n.d.

Chromosomes

DNA – We are unique – here‘s the math Egg and Sperm with 223 (or about 8 million) different combinations of chromosomes are produced through meiosis Sexual reproduction involves egg and sperm A sperm (with 223 different chromosome combinations) can fertilize an egg (with 223 different chromosome combinations) Any sperm can fertilize any egg 1 in 70 trillion chance you and non-identical twin sibling will be identical! Nicastro, n.d.

Genes Organism’s instruction manual, “blueprints” Each human has 50-100 trillion cells Each cell has a “genetic blueprint” that determines the function of the cell = “GENES” Complete set is a “genome” Humans have 20-25,000 genes that code for important traits A gene is a section of our DNA that determines a particular trait (Nicastro, n.d.; Berg, Tycmoczko, and Stryer, 2010)

DNA Human DNA is made up of individual molecules strung together, like a twisted ladder = “Double helix” Base pairs are the ladder rungs, (nucleotide), deoxyribose (sugar)-phosphase backbone These base molecules are either A, T, C, or G, and the order is VERY IMPORTANT 3 BILLION – 3000000000 – base pairs long! – Human Genome Project Remember = DNA stored on the chromosome ½ from mother + ½ from father = YOU ARE UNIQUE (UNLESS IDENTICAL TWINS) Crane, C. (2012) and Berg, Tycmoczko, and Stryer, (2010) https://askabiologist.asu.edu/sites/default/files/resources/articles/crystal_clear/Rosalind_Franklin_Plate_1_DNA_B_form_1000.jpg

Chromosomes

Genographic Project What is DNA? Mapping the human genome Forensics Group 1 Group 2 Class 1 82 95 Class 2 76 88 Class 3 84 90 What is DNA? Mapping the human genome Forensics Deep ancestral past

Mutations How are differences tracked? How are our places of origin tracked? Breaking the Code: https://genographic.nationalgeographic.com/science- behind/genetics-overview/

Single-Nucleotide Polymorphism (aka ‘snip’)- Mutations Random mutation of one of the base pairs, or “nucleotides” DNA passed from mother or father G is duplicated, deleted, or swapped AATCGGTTC This new code is passed down to subsequent offspring Harmless mutation

The Genome Project + SNPs 1990-2000 Geneticists, researchers and their students sequenced the ENTIRE human genome – order of the 3 billion base pairs Human Genome Project Now that we know the order of all base pairs, now what? Learn the genes (groups of base pairs) and the traits for which they code (National Human Genome Research Institute, 2015)

(National Human Genome Research Institute, 2015) 2000-Present Using SNPs, forensics can analyze DNA at a crime scene and pin-point an individual’s race/ethnicity, gender, genetic disorders, sex, age, origin King Tut, Queen Nefertiti, archaeological sites in Middle East, Aztec, Inca, Peru, remains Mass genocides – identify remains – Paris underground, Nazi’s mass graves at concentration camps, Rwanda, Bin Laden Who is interested? - DOJ, NIH, NIJ, FBI Labs, Smithsonian, State Crime Labs (National Human Genome Research Institute, 2015)

Genographic Project We are all similar – we all share a portion of identical DNA Each variant ethnic group shares genetic similarities Let’s wrap up International Week by celebrating that we are all of the human species, sharing 99.9% of our DNA with each other. You are 0.1% unique

SNPs and the Genographic Project All males alive today share the same genetic code, to a certain point – on the Y chromosome All PEOPLE alive today share same segment of mDNA (mitochondrial DNA) inherited from mother to children - mEve Oldest traceable SNP occurred in Eastern Africa 100,000 years ago, you get two variations (23 and me, 2015; Berg, Tycmoczko, and Stryer, 2010)

Next variation occurred later, around Northeastern Africa, near the Red Sea So on and so forth, and the Genographic Project traces indigenous, native populations, and the public’s, DNA/genetic record. SNPs in your DNA can trace back your “Deep Ancestry” to where these mutations first occurred, and which populations have same SNPs as you! https://genographic.nationalgeographic.com/ 23 and me, 2015; Berg, Tycmoczko, and Stryer, 2010)