What does the genome tell us about being humans? Flashcards
why do we compare genomes?
By comparing genomes between individuals we can find out where differences occur.
what are genome differences associated with?
- disease
- characteristics of an individual
- evolutionary history
What could we learn about an organism if we compare its
genome with others?
- What sort of genes do they have
- How differences between species arise
- Relationships between species
What does our Genome tell us about being human?
- By comparing our genome with animals that don’t do the things we do
- we might find where our genomes differ potentially the bits of DNA encoding our different biology
why is it hard to compare human genomes with the genomes of animals?
- There are lots of differences
- We share many of our genes with other animals
- We don’t really know what most genes do
how do we discover what is in common and what is different?
through comparative genome
what is conserved?
things in common are called conserved and encodes biology in common between species
how to compare sequence?
by lining them up next to each other and marking each point where sequences are the same
what is aligning?
by lining them up next to each other and marking each point where sequences are the same
DNA from dead things…
can remain in the environment
how can we find the genome of close relatives
-DNA from dead things can remain in the environment
-DNA degrades and is masked by more modern DNA
-DNA bases are also modified as they degrade, sometimes changing the sequence.
-Ancient DNA can be extracted and identified in very special circumstances.
-It has been used to determine the relationships of extinct animals, like moa
and mammoths.
how many Neanderthal nucleotides are there?
4 Billion
how many individuals did they gather this sequence from
3 individuals
important finds from Neanderthal DNA
-some of us carry Neanderthal DNA.
-Modern humans from Europe and Asia carry Neanderthal alleles.
-Those from Africa show no signs of these alleles.
-modern humans met Neanderthals, and they interbred.
do people with neanderthal DNA have a different set of genes?
no, it means DNA holds variants that arose in Neanderthals.
how much of the genome of non-Africans is made up of variants that arose in Neanderthals
2-4%
what does Neanderthal DNA do?
it adds to the variation in our genome that might be related to our phenotype
where was Denisova?
Denisova was a finger bone
does the Denisova genome match?
no Denisova mitochondrial DNA doesn’t match Neanderthal or Modern Human DNA
where was the genome of this species of archaic human found?
The genome from this species of archaic human was sequenced with a tooth found in the same cave in 2010
is Denisovan variation found in the human genome?
Denisovan variation is also found in the human genome
how much of the Denisovan variation is found in the human genome?
where it makes up 4-6% of the genomes of present-day Melanesians
how do we understand where our characters come from?
By comparing whole genomes from multiple species we can start to understand where our characteristics come from.
what does comparing genomes with other species do?
-help us identify variants that might be related to phenotype.
-help us identify variants related to the biology of an organism.
