UNIT 4 DAY 7 - EVOLUTION AND MIGRATIONS OF HOMO SAPIENS Flashcards
1
Q
Homo erectus
A
- spread from Africa to Europe
and West Africa to Central+SE Asia - About 700,000years ago, African populations of H. Erectus evolved into Homo heidelbergens
2
Q
Homo heidelbergensis
A
- Spread into Europe and West Asia where it began to evolve adaptations to cold climates of the north
- As European and West Asian heidelbergensis continued to evolve adaptation for life the cold, they evolved into Homo Neanderthalensis about 400,000 years ago
At the same time, Central and SE Asia, heidelbergensis evolved into Denisovans, known largely from recovered DNA
3
Q
Modern humans (homo sapiens)
A
- Evolved from African population of homo heidelbergensis about 300,000 years ago
- Then when they spread north (45,000 years ago), they encountered Neanderthals and Denisovans
- H. Sapiens occasionally interbred with both
4
Q
hybridisations
A
- -were uncommon enough that the three species did not merge back into one
-20% of Neanderthal DNA survives in modern humans in Africa, expressed in the skin, hair and diseases of modern people
-Denisovan genes are present in the genomes of natives of the Philippines, Australia and the Pacific Islands
5
Q
Morton
A
- early 19th century skull collector from Philadelphia
- scientist, doctor, racist
- believed cranial capacity equates to intelligence
- “craniometry” fuelled arguments for slavery
- modern understanding: all humans are closely related and that all people alive today are Africans
- skin colour: results of pigment mutations from population in different places
- ability to breathe air at high altitudes –> another advantageous trait
- some traits provided advantages in environments, others were “selectively neutral” –> sometimes unknown why certain mutations are favoured
6
Q
EDAR
A
gene variant present in East Asian, Native American but not among African/European descent
7
Q
Kamberov
A
- studied mice with EDAR and identified subtle differences (increased sweat glands, decreased fat around mammory glands) that could be advantageous
- more genetic diversity with Africa than other places –> people had more time to evolve there
- traits not “fixed” to locations: isolation, migrations, mixing blurred or erased them
- skin colours evolves as a result of genetic mutations (many different one exist), response to sun (selection for lighter/darker skin depending on climate)
8
Q
370A
A
- variant EDAR allele possessed by East Asians and Native Americans
9
Q
SLC24A5
A
- genes that gives Europeans lighter skin when “tweaked” –> not evolved until about 8,000 years ago
10
Q
Foeman
A
- DNA discussion project at WCU
- people often misunderstood their heritage, believing in correctly that their family is from somewhere –> people may look like 1 group, but DNA can tell another story
11
Q
homo sapiens journey
A
- oldest fossil discovered in Morocco 300,000 years ago
- 200,000 years ago: H. Sapiens spread through Africa
- 120,000 years ago: first wave out of Africa, migrate east almost to Australia
- 60,000 years ago: 2nd wave out of Africa
- phase 1 (50,000 years ago) –> east to australia
- phase 2 (45,000 years ago) –> increased north to central asia, europe (40K), N. america (20,000), S. America (15,000)
12
Q
4 major pigmentation genes
A
- mutations often involve a single nucleitide
- mutations evolved before H. Sapiens starting with H. erectus
13
Q
evolution of pigmentation
A
- involved multiple mutations in 4 different pigmented areas
- distribution of those genes among diverse population complex
14
Q
taxidermy
A
- Darwin learned from a black man, John
15
Q
European invention of race
A
- way to view people as less human and therefore be able to exploit them
