Biology 1Carmela Española

Room 107, IB Main Building

M 10-12AM

TTh 10-12AM & 3-5PM

1. Who is the Real Eve?

2. Where and when did she live?

3. What is the scientific basis that a Real Eve existed?

4. What is mitochondrial DNA (mtDNA)?

5. How is mitochondrial DNA passed through generations?

6. How many years ago did the first hominids appear?

7. When did this group of hominids migrate out of Africa?

8. What was their migration route?

9. What were the primary causes of the migration of hominid groups?

10. When did modern-day humans first migrate into what is now Europe?

11. What hominids had been living in this region for hundreds of thousands of years?

12. What caused humans to evolve into different races with unique characteristics?

Human Evolution

Biological and Cultural

The primates (Class Mammalia, Sublass Eutheria, Order Primates)

• Opposable thumbs

• Frontally directed eyes

with binocular vision

• Large and convoluted

brains

• Complex social

behavior

• Earliest primate (prosimian)

arose 65 MYA when

dinosaurs became extinct

HUMAN EVOLUTION

Suborders of Order Primates

1. Suborder Prosimii

• Known as Prosimians

• Found in tropical rain forests in Madagascar, Africa and Southeast Asia

• May be polyphyletic, with the tarsiers being a separate group

• Skull has large orbits, reduced brain case, elongated snout, and well

developed olfactory and auditory regions

Philippine tarsier Ring-tailed lemur Slender loris

Suborders of Order Primates

2. Suborder Anthropoidea

• Monkeys and apes (including humans)

• Rely more on sight and less on sense of smell as in prosimians

• Larger brain relative to body size

Old World Monkeys New World Monkeys

• Africa and Asia • Central and South America

• Tails are NOT prehensile • Tails are prehensile

• Nostrils face downwards • Nostrils face sideways and are wide apart

• All are arboreal• Arboreal and ground-

dwelling

BaboonRhesus macaque Spider monkey Golden lion tamarin

Suborders of Order Primates

2. Suborder Anthropoidea

Gibbon Orangutan Chimpanzee

Man

Gorilla

NOTE: Human & chimp

DNA are 98.4% alike

Suborders of Order Primates

2. Suborder Anthropoidea

Are we monkeys?

• Humans are apes, which are different

from monkeys

• Apes are capable of BRACHIATION

(arm swinging) but not monkeys

• The collar bones in apes are longer

keeps the shoulder away from the chest

• Makes the shoulders free to move; apes

can scratch their left ear with their right

hand, but monkeys can’t

• Humans and other apes did not come

from monkeys; rather, both have a single

common ancestor

• Monkeys have tails; apes have none

• These primates lack tails

and have forelimbs

longer than their hind

limbs (except humans)

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PROSIMIANS ANTHROPOIDS

MONKEYS APES

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ANCESTRAL PRIMATE

The Great Apes

Hypothetical

evolutionary history

of humans

Species Lived when

(MYA)

Lived where

Adult length

(m)

Adult weight

(kg)

Brain volume

(cm3)

Fossil record

Others

Australopithecus afarensis

3.9- 2.9

East Africa

1.1 29 380-430 ‘Lucy’ + others

Bipedal

Australopithecus africanus

3.3- 2.4

South Africa

400-500 Several Bipedal

Homo rudolphensis

1.9 Kenya 1 skull

Homo habilis

2.5- 1.5

Africa 1.0-1.5 30-55 600 Many Made tools from bone and stone

Homo erectus

1.8-0.07 Africa, Eurasia,

Java

1.8 60 900-1100

‘Peking Man’

+ others

Upright walk;

used fire; more

complex tools

Homo ergaster

1.9-1.25 E. and S. Africa

1.9 700-850 Many

Homo heidelbergensis

0.6-0.25 Europe, Africa, China

1.8 60 1100-1400

Many

Homo neanderthalensis

0.23-0.03

Europe, W. Asia

1.6 55-70 1200-1700

Many May have used

language; adapted to

cold climate;

may have buried their

dead Homo

sapiens 0.25-

present World-wide

1.4-1.9 55-80 1000-1850

Still living

With modern human

behavior

Recent updates on human evolution

Ardipithecus ramidus (“Ardi”)

• Oldest known hominid found (Ethiopia)

• Lived around 4.4 million years ago

• weighed about 110 pounds, had very

long arms and fingers, and possessed

an opposable big toe that would have

helped her grasp branches while

moving through trees

1. Multiregional hypothesis

Two hypotheses on the origin of humans

2. Recent single

origin hypothesis

Two hypotheses on the

origin of humans

2. Recent single origin hypothesis

Two hypotheses on the origin of humans

Key trends in human evolution

1. Terrestriality

- Coming down from trees

2. Bipedalism

- Obligately having to walk on two feet

3. Encephalization

- Increase in brain size relative to body

- Development of language

5. Civilization

- Complex technology, moral systems, society

4. Behavior

- Increasingly complex with some key ingredients

1. Abstract thinking

2. Planning

3. Innovation

4. Symbolic behavior

- Concepts free from specific examples

- Taking steps to achieve a farther goal

- Finding alternative solutions

- Making use of images and rituals

Four ingredients of human behaviour

Tracing human history through genetic mutations

Are we still evolving?

High Altitude Genes (EPAS1)

• Lowlander response

– Produce more red blood cells

– Help transport oxygen more efficiently

• Tibetan highlander response

– Produce less red blood cells

– too many red blood cells = blood too thick

particularly dangerous for pregnancy

High Altitude Genes (EPAS1)

• When genome was compared to Han Chinese

– Region EPAS1 different

• Split between Tibetans and Han Chinese

– Estimated to be less than 3,000 years ago

– Pretty fast evolution (~100 generations)

Lactose Intolerance

• Found in 10% of Americans, 10% of

Africa's, Tutsi tribe, 50% of Spanish and

French people, and 99% of Chinese

• Lactose cannot be digested (lacks lactase)

• Gene that makes lactase is shut down

after weaning

Lactose Tolerance

• Lactose tolerance advantageous in people who have access to

animal milk

• Drink milk directly rather than process (e.g. Cheese)

• Provide additional sustenance and, during droughts, a source of

water

• Parallel evolution: Europe and Africa

Wisdom Teeth

• Quadruped

– Advantageous for diet (leaves, roots, raw meat), large jaws that accommodate all 32 teeth

• Biped

– Hands can be used to obtain food; jaws became smaller

• Increased intelligence

– Cook and process food; reliance on third molar decreased

• Mutation in MYH16 gene produces smaller jaws

Cultural Evolution

What is more diverse in humans,

biological (genetic) or cultural diversity?

Cultural Diversity

• Ethnologue: approximately 6909 extant languages

• Price’s Atlas of Ethnographic Societies: over 3814 distinct

cultures having been described by anthropologists, certainly a

major underestimate.

Cultural Diversity

• If all the world’s languages were evenly distributed across the

habitable world

– An average journey of 78 km would bring a traveler from the centre of

their language territory to a language boundary.

– 1000 km would pass through over six language territories.

– The traveler across the same distance would be less able to distinguish

major phenotypic differences, and would see few marked boundaries.

“

”

Language allows us to interact with the world in so many

ways, almost like seeds adapted to local conditions,

land races that make the best use

of local conditions.

Felipe Montoya Greenheck

• There are at least

120 languages in

the Philippines

alone, in an area of

799,674 sq. km.

• But we don’t look

that different from

each other....

Cultures are the consequence of [formation of boundaries between human communities], and boundary formation is

perhaps the central and most important element of the evolutionary ecology of culture.

What leads to diversification of cultures?

• Resources, ecology and environment

• Kinship and reproduction

Outcomes of Forming Cultures

• Biologically-related individuals likely share a culture

– Culture constrains biology (choice of mate and gene transfer)

• Regional Diversity

– High levels of geographic isolation

– High gradient in resource availability

• Extinction

Sources

• Modified Bio 12 slides

• Dr. Catherine Lagunzad

• Dr. Ian Kendrich Fontanilla

• Dr. Ma. Lourdes Tongco

• Foley and Lahr. 2011. The Evolution of the Diversity of Cultures.

• Tabbada et al. 2010. Philippine Mitochondrial DNA Diversity: A Populated Viaduct between Taiwan and Indonesia?

The Evolution of Sex

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