1. Neanderthals and Disease Genes
Group E - Julia Walker, Kimmi Vo, S. Chiamaka Okorie, George Fabrikarakis, Scott Hill, Emily DePina
Kelly Bower

2. What is a Neanderthal? A) An earlier kind of human
B) An extinct species of human
Kelly Bower

3. Neanderthal Origins
At minimum, there have been 20 different kinds of hominids on earth over the last 4.4 million years
First hominids originated in Ethiopia
Earliest Neanderthals lived in Europe and western Asia approx. 200,000 years ago
Left impressive records of themselves, great with stonework
Kelly Bower

4. Kelly

5. Denisovan Origins Separate population from Neanderthals
Related through Common Origin
Both present in Eurasia when humans emerged from Africa
Interbred with humans and Neanderthals
Scott

6. Modern Humans Origins
Homo Sapiens originated in Africa (100, ,000 years ago)
Entered Europe (approx. 40,000 years ago)
Had basic stone, antler and bone tools + basic culture (art, music, records)
Neanderthals less advanced
H. Sapiens only hominids present for approx. last 25,000 years
Julia Walker

7. Gene Flow
Possible Model
Julia Walker

8. DNA Analysis Ancient DNA very difficult to work with
Fragmentation begins very soon after death
Average length of old molecules; approx base pairs
Must amplify DNA fragments to study
PCR: multiplication of DNA in test tube, brings back correct sequence
George polymerase chain reaction

9. Comparison of DNA very revealing:
Allow scientists to detect shared variants and estimate degree to which sequences related
Can discover how populations related to one another, time since split and periods of expansion and contraction in size
As population shrinks, genetic diversity declines
Learn about dynamics of genetic change in populations over time
George

10. What is NOT a benefit of DNA analysis?
A) Clearly examine ancient DNA
B) Detect shared variants
C) Discover how populations relate to each other
D) Estimate time since population split
George

11. Neanderthal Genes in Modern Humans
Neanderthals: extinct species of human - differing in DNA only by .12%
Eurasia
Modern humans: archaic homo sapiens evolved to anatomically modern humans solely in Africa
Africa
Kimmi Vo - so how does this affect us? We mainly originate from modern humans

12. Interbreeding between species
Interbreeding w/ modern humans (homo sapiens) led to non-Africans
Middle east, not Africa as most expected
Neanderthal genes helped modern humans adapt to non- African environments
We all have more Neanderthal genes that we think
Kimmi

13. “Neanderthals Gave Us Disease Genes”
New study: disease-causing genes arose from interbreeding with Neanderthals
Interbreeding not thought possible in past
Beneficial and malignant gene transfer
Genome studies reveal: human genome 2-4% Neanderthal genes
Emily

14. Neanderthal Genes Now
Alleles enriched for genes affecting keratin filaments
Genes not evenly distributed - found to affect skin and hair
No sex-linked genes, many had harmful effects removed through natural selection
infertility, sterilization
Emily

15. What percent of the human genome has Neanderthal genes?
B) 15% -24%
C) 2% - 4%
D) 6% - 10%
Emily

16. Modern Day Impact Neanderthal DNA slowly “purged” from environment
Largely-negative gene variants remain and have led to modern day diseases. Could these benefit in another way?
Chiamaka
-natural selection flushed out bad genes
-we still have the DNA because admixture happened early in the evolutionary line

17. Neanderthal Genes In Us
Type 2 diabetes
Long-term depression
Lupus
Biliary Cirrhosis
Markers that affect chance of Crohn’s disease
Chiamaka
-markers that increase/decrease chance of Crohn’s
-don’t know if neanderthals also had these diseases or if they only passed on genes that affected the risks

18. Sources
mated-interbred-dna-gene/
Tanstall, Ian. “Once We Were Not Alone.” Scientific American Print.

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