Biological and cultural evolution of the hominins

Year 13 Biology

Achievement Standard 3.7

Possible family tree of the various hominins

Characteristics of the very early hominins Using pages 306 – 320 of your CB book,

create “recipe cards” to help you learn the biological and cultural evolution of the following fossils. Remember: you need to know TRENDS in the

biological and cultural evolution of humans, however learning the names and features of each of the important fossils will help you put the picture together.

Characteristics of the very early hominins Sahelanthropus tchadensis Australopithcus genus

A. ramidus, A.anamensis, A. afarensis, A. Africanus

Paranthropus genus P. aethiopcus, P. robustus, P. boisei

Homo genus H. Habilis, H. erectus (asian), H. ergaster

(african), H. Heidelbergensis, H. neanderthalis, H.sapiens idaltu, H.sapiens

Cultural Evolution trends

Sahelanthropus tchadensis

Lived in wooded areas

Most of cultural evolution is pure speculation

Australopithecus group

Only debatable evidence that they made tools, and no evidence that they had home bases or shared food. Probably opportunist feeders.

Paranthropus genus

Some evidence they used bones or perhaps sticks to dig up roots (this would leave no fossil evidence though)

Evidence suggests robustus ate course, tough food supplemented by small insects.

Cultural evolution trends

Homo genus Development of speech Enabled by Broca’s area of the brain. First seen in H.habilis.

Development of tool-making H. habilis was known as the Handy man and made Oldowan tools. H. erectus used Acheulian tools and was known as the Fire maker.H.Neanderthalis used Mousterian tools and began to attach stone tools to handles.H. sapiens used advanced tools of flint and bone. Used blades and points. Called Upper Palaeolithic tools.

Cultural evolution trends

Homo genus Development of group living and cultureH. habilis – successful hunters, made shelters and lived in bands of about 12 peopleH. erectus - built shelters (huts) supported by wooden poles, serious co-operative huntersH. heidelbergensis – able to hunt large prey (rich diet led to increased size), were cannibals, built shelters and used fireH. neanderthalis – intelligent, lived in caves, built stone walls, dressed in hides, buried their dead, had strong social bonds.H. sapiens – skilled hunters, lived in large groups, engraved and painted on walls, carved statues etc

Cultural Evolution in Humans

Can be defined as; Tools, books, writing, art, language, music,

ritual etc Is passed down by teaching (oral or written) Is fast

The home base theory

At some sites, concentrations of tools, stones from other areas and bones are found.

This suggests that early hominins were not just carrying things around, but were focusing on one site as a home base.

Adults hunted and left young behind, and then brought all produce back to be shared

Sharing of food lead to complex societies Clearly defined by the time of Homo erectus

Communication

Facial expressions important Speech

Culture requires intelligence and communication

Areas of the brain essential for structure and sense of speech

Broca’s area – concerned with speech Wernicke’s area – concerned with

comprehension of language The lower the voice box, the more sounds can

be articulated.

Communication

Singing and chanting Essential for remembering kinship lines and

tribal history Better hearing and listening skills as a result

of speech Art – drawings of pictures and symbols on

cave walls, bone carvings, clay statues

Development of Agriculture

Learning to cultivate a food-producing plant; not just gathering a naturally occurring plant.

Domestication of animals – dogs, sheep, goats, pigs, cattle

Why start agriculture? Population expansion Shortage of food Climate change Need to be near a constant water supply

Development of Agriculture

Disadvantages; Living close together means chances of

diseases spreading is increased Diet not as varied so could have suffered from

malnutrition Stored food could spoil

The dispersal of humans

The Multiregional Theory

Extending from the populations of H.erectus there were populations of humans living around the world, and all of these contributed to successive generations – eventually leading to modern humans. In other words – Homo sapiens evolved

independently in several places around the world.

Predictions of Multiregional

Transitional forms found in many places Modern traits should appear around the world

simultaneously There should be a high degree of diversity in

humans as Homo sapiens is a very old species

Evidence for Multiregional

Asian fossils show a clear transition from older hominid to modern H.sapiens

The oldest H.sapiens fossils outside Africa were in Australia, and are 60 000yrs old.

Northern china fossils show no evidence that African features ever replaced the ancient Chinese in this region Instead there is a smooth transformation of

ancient peoples into the present populations of East Asia and the Americas.

Evidence of Multiregional

Post-Neanderthal people in Europe show mixtures of modern and archaic African features

Mitochondrial DNA analysis is flawed because; Present-day patterns cannot show links that

become extinct Whenever no daughters are produced the

mitochondrial line dies out

Replacement – “Out of Africa” model

Intial migration of early Homo, such as H.erectus, H.heidelbergensis and H.neanderthalis, did not contribute to modern humans, but there was a second wave of new humans out of Africa approx 200 000years ago.

It was a fully modern H.sapiens that then replaced whatever populations then occupied Asia and Europe

Predictions of “Out of Africa”

Transitional forms found mainly in Africa Modern traits found first in Africa and then

later elsewhere as they spread Since the species is young there should be

little diversity

Evidence for “Out of Africa”

Mitochondrial DNA shows high degree of similarity between all modern human populations that most likely occurred with the past 150 000 – 200 000 years ago

The oldest H.sapiens fossils have only been found in Africa, 80 000 – 120 000 years old

Humans arrived in Europe late – about 80 000 years ago

Evidence for “Out of Africa”

Mitochondrial DNA of Neanderthals, Cro-Magnons and 21st century Europeans that was compared and showed: Modern humans showed similarity with Cro-Magnons Modern humans showed no similarity with

Neanderthals Mitochondrial DNA all lead back to Africa, showing

that Africa is the place of origin for modern humans. Large levels of gene flow between continents would

be required for multiregionalism (unlikely)

Evidence for “Out of Africa”

Fossil evidence shows that moderns humans appeared in Africa before the Neanderthals had disappeared in Europe so could not be descendants of the Neanderthals