Evolution: Dispersal Patterns

Question 1

What does the Multiregional Hypothesis suggest about the migration of Homo Erectus?

Answer 1

Homo Erectus migrated out of Africa about 1.8 million years ago, spreading to Europe and Asia while simultaneously evolving into Homo Sapiens.

Question 2

How did continuous gene flow affect human populations according to the Multiregional Hypothesis?

Answer 2

It ensured adaptations were spread to all populations, leading to similar features among all humans.

Question 3

What evidence supports the idea of interbreeding between Homo Erectus, Neanderthalensis, and modern Homo Sapiens?

Answer 3

Fossils and DNA evidence show regional intermediates between these species, indicating that interbreeding occurred.

Question 4

What percentage of Neanderthal DNA is found in modern Europeans?

Answer 4

Up to 4%, with at least 2.5% being common. (Supports Out of Africa theory - interbreeding occured, species interacted.)

Question 5

Why is the Multiregional Hypothesis considered unpopular?

Answer 5

It requires high levels of gene flow, which is unlikely, and genetic evidence shows less variation than expected.

Question 6

What does mtDNA evidence suggest about the variation within a species?

Answer 6

Significant variation within mtDNA can occur within a species, as seen in a subspecies of chimpanzees.

Question 7

What do regional differences in some populations suggest according to the Multiregional Hypothesis?

Answer 7

They suggest regional adaptation, similar to Homo Neanderthalensis.

Question 8

What is a major issue with using fossil evidence to support the Multiregional Hypothesis?

Answer 8

Fossils cannot confirm a species’ ability to successfully interbreed.

Question 9

What does the presence of intermediate fossils between Homo Erectus and Homo Sapiens in Israel suggest?

Answer 9

It suggests that some gene flow occurred and that these fossils are close to Africa.

Question 10

Why is the belief that 170,000 years is too short to develop racial differences significant?

Answer 10

It supports the idea that interbreeding and regional adaptation took longer, aligning with the Multiregional Hypothesis.

Question 11

What is a commonality between the Multiregional Hypothesis and the Out of Africa theory?

Answer 11

Both use genetic and fossil DNA to support their claims but interpret it differently.

Question 12

What does the mistrust of mtDNA evidence imply about the Multiregional Hypothesis?

Answer 12

It implies skepticism about the genetic data supporting the Out of Africa theory.

Question 13

What does the presence of Neanderthal DNA in modern Europeans indicate?

Answer 13

It indicates that interbreeding took place in the past.

Question 14

Why is the Multiregional Hypothesis highly questionable based on recent genetic research?

Answer 14

Because mtDNA and Y chromosome DNA reveal less variation than expected, suggesting a later migration out of Africa.

Question 15

What do regional differences in physical traits, like noses, suggest about human evolution?

Answer 15

They suggest regional adaptation and make it difficult to classify species as differences may represent variations within a single species.

Question 16

What does the Out of Africa theory suggest?

Answer 16

Homo Erectus left Africa 1.8 million years ago, spreading to Europe and Asia, where they evolved into Neanderthals and Denisovans. These populations were reproductively isolated from each other and Africa, with no gene flow.

Homo Sapiens evolved later, within Africa, and migrated out around 100,000 years ago. By 50,000-60,000 years ago, they spread into Europe and Asia, interbreeding with Neanderthals and Denisovans, leaving traces of Neanderthal DNA in non-African populations.

Homo Sapiens coexisted with other hominins but, due to superior tools, social structures, and adaptability, outcompeted them, leading to their extinction.