genomes to ecosystems lecture 4- evolutionary genetics Flashcards
what is comparative anatomy?
morphology suggests that humans and apes are related as they have lots of similar characteristics
how is sequencing dna made easy?
there’s a device that can sequence a genome in a few hours at a cost of £1000. specific analyses can be completes with a few days
how long ago did neanderthals and humans co-exist in Europe?
as recent as 30,000 years ago
what is the difference in species between 100,000 years ago to 25,000 years?
homo neanderthalensis existed in Europe, homo Erectus existed in asia and homo sapiens existed in africa originally then moved to just Homo sapiens
what’s an example of sequencing ancient dna? (Oetzi the iceman)
In 1991, Oetzi’s remains were found in a Glacier in the Italian alps.
Analysis of his DNA suggests that:
He died 5300 years ago
He is ethnically Central European
He may have been sterile
To Quote a Top Scientist:-
“At first it was thought that Oetzi had died from exposure to cold but wounds on his hands and an arrowhead lodged in his back suggest a more violent death”
do we share dna by descent?
Finding close relatives is very accurate, but distant relatives less so.
It also needs these relatives to be in their database.
what is the founder effect?
when members of a population go elsewhere to populate somewhere else
what is an example of founder effect?
Tristan du Cuhna is the most isolated human population on Earth. Tristan da Cuhna is actually a very big volcano, erupted in 1961
It is 3400km from Rio de Janeiro and 800km from Cape Town
The current population of 264 is descended from 15 ancestors (8 male and 7 female) who arrived between 1816 and 1908, especially one Scottish family arriving in 1817. only 7 surnames survive
inbreeding is so high that all islanders are cousins, and any two siblings are cousins by approximately 50 different routes
does founder affect have an affect on asthma?
According to Noe Zamel 23% of Islanders have asthma, with 57% showing some asthmatic symptoms. He suggests three ancestors were asthmatic.
what is evolutionary medicine?
Islanders are likely to share the same pre-disposition genes.
Islanders are essentially a single giant family
what is genealogy?
Nine Y-chromosome haplotypes were found. Seven can be unambiguously associated with the seven surnames.
These fall into two haplogroups:
I: from south-western Europe (Italy)
R: from north-western Europe (Dutch, English, Irish & Scottish).
how much percentage of human variation pre-dates humans leaving africa
over 90%
what is the molecular clock?
when dna sequences change from ancestors through time, reflecting evolutionary history
