Bio 140. Human evolution

1. Bipedalism

2. Big brains

3. Similar sized sexes

4. Extended childhood

5. Precision grip

Physical traits that make us human

Bipedalism

Physical traits that make us human

through a series of anatomical changes to our skeleton, affecting our cranial base, spine, pelvis, femur, knees, and feet.

Big brains

Physical traits that make us human

~3x larger than an animal of our size

Big brains

Physical traits that make us human

linked to ability to create more complex tools, more advanced hunting techniques, complex social structures and the advent of language

Similar sized sexes

Physical traits that make us human

reduction in sexual dimorphism (difference in size and shape between males and females) is closely linked to greater cooperation within a population and probably  in the development of successful societies and civilizations.

Extended childhood

Physical traits that make us human

unlike most primates, we are still helpless after weaning; _____________ appears to have first developed in the Homo genus., in H erectus after about 1.9 million years.

Precision grip

Physical traits that make us human

 the result of changes in the anatomy of the hand

metacarpal styloid process

Physical traits that make us human

a little projection of bone; it locks the hand bone into the wrist bones

metacarpal styloid process

Physical traits that make us human

allows greater amounts of pressure to be applied to the wrist and hand from a grasping thumb and fingers

1. Ability to make stone tools

2. Walking on two legs / Bipedalism

3. Invention of cooking

Some Milestones in Human Evolution

Ability to make stone tools

Some Milestones in Human Evolution

Apes use found objects as tools, but the shaping of sticks and stones to particular uses was the first recognizably human activity

Invention of cooking

Some Milestones in Human Evolution

allowed humans to extract more energy from meat which led to the evolution of the human brain. Bigger brains and more dextrous hand led to the development of complex societies.

• hominid

Approximately 98% of our genome is similar to other apes

• together with other apes comprise of the __________ family/lineage, the family of great apes, spearated from the monkeys. 

Hominin

___________

• lineage leading to modern humans that split from the chimpanzee-human common ancestor hominids that are sister groups of chimpanzee

Sahelantropus tchadensis

________________

• lived around 7 MYA

• adaptations for walking bipedally, smaller canine teeth

Sahelantropus tchadensis

Austrolophithecus afarensis

Homo habilis

Homo ergaster

Homo erectus

Homo heidelbergensis

Homo sapiens

Neanderthals

Denisovans

Austrolophithecus afarensis

__________________

• lived around 3.9 - 2.9 MYA

• They had enlarged cheeks, teeth, and jaws. Shorter than humans.

Sahelantropus tchadensis

Austrolophithecus afarensis

Homo habilis

Homo ergaster

Homo erectus

Homo heidelbergensis

Homo sapiens

Neanderthals

Denisovans

Homo habilis

_______________

• 2.1 - 1.5 MYA

• Larger brain, capable of precision grip, ability to make simple small tools

Sahelantropus tchadensis

Austrolophithecus afarensis

Homo habilis

Homo ergaster

Homo erectus

Homo heidelbergensis

Homo sapiens

Neanderthals

Denisovans

Homo ergaster

________________

• 1.8 - 1.3 MYA

• look more like modern humans

Sahelantropus tchadensis

Austrolophithecus afarensis

Homo habilis

Homo ergaster

Homo erectus

Homo heidelbergensis

Homo sapiens

Neanderthals

Denisovans

Homo ergaster

• "ergater" - "workman"

• various tools near skeletal remains of ____________

Sahelantropus tchadensis

Austrolophithecus afarensis

Homo habilis

Homo ergaster

Homo erectus

Homo heidelbergensis

Homo sapiens

Neanderthals

Denisovans

Homo erectus

smaller jaws and cheek teeth, long legs and arched feet well-suited for long-distance walking and running, larger brain

Homo heidelbergensis

__________________

• 0.6 - 0.3 MYA

• Larger brain size, believed to be ancestors of modern humans, used to live in Africa, then later on moved onto Asia and evolved into the neanderthals

Sahelantropus tchadensis

Austrolophithecus afarensis

Homo habilis

Homo ergaster

Homo erectus

Homo heidelbergensis

Homo sapiens

Neanderthals

Denisovans

Homo sapiens

_______________

• 200 KYA

• capacity for full-blown language

Sahelantropus tchadensis

Austrolophithecus afarensis

Homo habilis

Homo ergaster

Homo erectus

Homo heidelbergensis

Homo sapiens

Neanderthals

Denisovans

AFRICA

Humans originated from ___________

Neanderthals

______________

• They interbred with modern humans

• Around 4% of the genome of french, han-chinese, and papuan people have ____________ DNA

• Evolved in Europe and Asia

Sahelantropus tchadensis

Austrolophithecus afarensis

Homo habilis

Homo ergaster

Homo erectus

Homo heidelbergensis

Homo sapiens

Neanderthals

Denisovans

Denisovans

________________

• Modern humans have an admixture of _____________, meaning interbreeding between the two species occurred.

Sahelantropus tchadensis

Austrolophithecus afarensis

Homo habilis

Homo ergaster

Homo erectus

Homo heidelbergensis

Homo sapiens

Neanderthals

Denisovans

H. Otley Beyer; Wave migration theory

_______________ - _________________

• suggests that the ancestors of modern Filipinos traveled to the archipelago in different waves of migration

• negritos, then Indonesians, then Malays

Austronesian

a language family that is widely distributed throughout maritime Southeast Asia, Madagascar, and the Pacific Islands, with a few members in continental Asia.

Out of Taiwan theory

suggests that the first Austronesians reached the Philippines from Taiwan, settling the Batanes Islands and northern Luzon, then spread towards the rest of the Philippines and Southeast Asia

Taiwan

___________ is the homeland of Austronesian speakers

culture; technology

Humans are continuing to evolve, but now the evolution is driven much by _________ and _____________.

Thrifty gene

Polynesian obesity and the __________

• ____________ hypothesis - maintaining a larger build to store enough energy (in fat) to endure long journeys at sea.

The Pygmy Phenotype

____________________

• Human adaptation for coping with food limitation, warm, humid conditions, and dense forest

The Pygmy Phenotype

A consequence of early growth cessation that evolved to facilitate early reproductive onset amid conditions of high adult mortality.