Where do all human come from?
AFRICA
Around how many years ago did MODERN human appear in Africa?
300 000 years ago
When did dispersal of human population occur from Africa?
- 70 000 years ago to all over the world
What is MULTIREGIONAL EVOLUTION?
- theory by which there were a lot of apes throughout the world and every population evolved independently
How was MULTIREGIONAL evolution proved wrong?
- Genetics
clearly tell that ALL modern human trace back to Africa - Hence it was due to dispersal that variation raised and not MULTIREGIONAL EVOLUTION
What does the AFRICAN HETEROZIGOSITY GRAPH TELL US?
- IT clearly shows that as POPULATIONS move further away from africa hereozigosity which is GENETIC VARIATION decreases
- This makes a lot of sense, because Africa was the most variate
- So let’s suppose Africa has a variation of 100
- A small population moves out of Africa it will be like genetic drift in some terms, as wherever the population moved to, population will descend from the individuals that move so GENETIC VARIATION obviously decreases
What is EFFECTIVE POPULATION SIZE?
- It includes humans that can reproduce! Hence excluding old people and childrens
Are Homo neandhertals our ancestors?
No! It is a different Homo species which dispersed from Africa before us
What particular FACE feature do Homo Neanderthals have?
Brow ridge
How did Neanderthals live as a population?
In groups
What suggests that Neanderthals used animal hides?
- 50 000 year old Neadhertal skulls of a male shows that teeth are worn out
- teeth used to hold animal fabric to prepare clothes and stuff
What are few particular characteristics that Neanderthal showed similar to humans?
- They made jewellery
- cave ART
- buried they’re dead
What could be a reason why Neanderthals disappeared?
Exact reason unknown
- hypothesised that they were a very small group of population which very dangerous in terms of survival
What did Neanderthals sequencing reveal?
Around 3% of our DNA comes from Neanderthals, so from a biological point of view we are not different species although we are.
Did Neanderthals and Homo sapiens ever breed? What suggests this?
- Yes, it is not understood what cause the interbreeding but the fact that our DNA is 3%ish Neanderthals it indicates interbreeding did occur in-between Neanderthals and human.
What evidence helped us discover Denisovans?
- FINGER BONE found in a cave
- finger bone DOES NOT match anatomical structure of Homo Sapiens and Neanderthals; so another type of smart species existed which was named DENOSIVANS.
What is the relation between DENISOVANS and Tibetans?
Tibetans got they’re EPAS 1 gene from Denisovans as Denisovans lived in altitude everywhere across Asia like Tibetans now.
What is INTROGRESSION?
Exchange of genes
What indicated that Denisovans used boats?
- Land1 - water - Land2
- Denisovans fossils found in both lands
- Wallace noticed that terrestrial animals in Land1 not present in Land2
- So there was no possibility of crossing terrestrially
- Hence Denisovans must have been able to use boats
Neanderthals and Denisovans smelling and it’s relation to Humans?
- Androsterone has a particular odour detected by one receptor only
- Neanderthals = had receptor which caused them to NOT LIKE this odour
- Denisovans = genetic make up of the receptor would’ve caused Denisovans to LIKE this receptor
- Human = some like it some dislike it , if you have a Neanderthal make up of this receptor then you are likely to NOT like it
Denisovan make up of this receptor within your DNA you are likely to LIKE aldosterone smell.
