What does the human genome tell us about being human

Question 1

what can we learn about genomes using comparative genomics

Answer 1

1. to discover what is in common and what is different
2. things that are in common may encode biology in common between species
3. things that are different may encode organism specific biology
4. by comparing genomes we can learn a bit about which parts of the genome does what

Question 2

what are genes in common called

Answer 2

conserved

Question 3

how do we compare sequences of genomes

Answer 3

through the process of aligning

Question 4

what is aligning in genome sequencing

Answer 4

comparing genomes by lining them up next to each other and marking each point where sequences are the same

Question 5

what could we learn about organisms if we compare its genomes with others

Answer 5

1. what sorts of genes they have
2. how differences between the species arise
3. the relationship between species

Question 6

how do we gather DNA from dead things

Answer 6

DNA from dead things remain in the environment

Question 7

why is DNA from the environment not always accurate

Answer 7

DNA degrades and can be masked by more modern DNA

Question 8

what happens to the DNA bases as DNA degrades

Answer 8

DNA bases are modified as they degrade and sometimes this can change sequences

Question 9

some DNA has been extracted and identified in special circumstances - what has it been used for

Answer 9

used to determine the relationships of extinct animals

Question 10

what did they find when they compared Neanderthal genome to Humans

Answer 10

1. 4 Billion Neanderthal nucleotides.
2. Identified and discount modern contamination.
3. Gathered sequence from 3 individuals (probably).
4. Enough sequence to compare with modern human genome sequences from around the world.
5. Identified bits of DNA that differ between Neanderthals and us.

Question 11

what were their greatest findings when comparing Human genomes to the Neanderthal

Answer 11

1. Some of us carry Neanderthal DNA.
2. Modern humans from Europe and Asia carry Neanderthal alleles.
3. Those from Africa show no signs of these alleles.
4. The most parsimonious explanation for this is that where modern humans met Neanderthals, they interbred.

Question 12

what does it mean that some of us as Humans carry Neanderthal DNA

Answer 12

it just means that our DNA holds variants that arose in Neanderthals

Question 13

2-4% of the genome of non-Africans is made up of variants that arose in Neanderthals - what does it tell us

Answer 13

Neanderthal DNA adds to the variation in our genome that might be related to phenotype

Question 14

what else was found in Denisovan that is not related to Neanderthals

Answer 14

a finger bone - the mitochondrial DNA does not match Neanderthal or modern DNA

Question 15

what was the finger bone DNA sequenced with

Answer 15

a tooth found in some cave in 2010

Question 16

where is the Denisovan variation found in the human genome - race

Answer 16

it makes up 4-6% of the genomes of present day Melanesians

Question 17

what did all the variation found in DNA, Denisovan and Neanderthals tell us

Answer 17

1. The sequencing of genomes has helped us better understand who we are and where we came from.
2. The key technology here is being able to compare genomes.
3. By comparing whole genomes from multiple species, we can start to understand where our characteristics come from.
4. This is the same approach used in modern disease genetics- data rich and statistically intense analysis
5. Our extinct relatives are not just fossils in our museums but live on as variants in our genomes which affect our biology.