Illustration Ivan Allen 1 HOMO HABILIS NICKNAME Handyman

Illustration: Ivan Allen 1 HOMO HABILIS ~ NICKNAME: Handyman LIVED: 2. 4 to 1. 6 million years ago HABITAT: Tropical Africa DIET: Omnivorous – nuts, seeds, tubers, fruits, some meat 2 HOMO SAPIEN ~ NICKNAME: Human LIVED: 200, 000 years ago to present HABITAT: All DIET: Omnivorous - meat, vegetables, tubers, nuts, pizza, sushi 3 HOMO FLORESIENSIS ~ NICKNAME: Hobbit LIVED: 95, 000 to 13, 000 years ago HABITAT: Flores, Indonesia (tropical) DIET: Omnivorous - meat included pygmy stegodon, giant rat 4 HOMO ERECTUS ~ NICKNAME: Erectus LIVED: 1. 8 million years to 100, 000 years ago HABITAT: Tropical to temperate - Africa, Asia, Europe DIET: Omnivorous - meat, tubers, fruits, nuts 5 PARANTHROPUS BOISEI ~ NICKNAME: Nutcracker man LIVED: 2. 3 to 1. 4 million years ago HABITAT: Tropical Africa DIET: Omnivorous - nuts, seeds, leaves, tubers, fruits, maybe some meat 6 HOMO HEIDELBERGENSIS ~ NICKNAME: Goliath LIVED: 700, 000 to 300, 000 years ago HABITAT: Temperate and tropical, Africa and Europe DIET: Omnivorous - meat, vegetables, tubers, nuts 7 HOMO NEANDERTHALENSIS ~ NICKNAME: Neanderthal LIVED: 250, 000 to 30, 000 years ago HABITAT: Europe and Western Asia DIET: Relied heavily on meat, such as bison, deer and musk ox

Who are we, anyways? • Kingdom-animalia – Phylum—chordata • Class—mammalia – Order—primate » Suborder—anthropoidea --Family—hominidae --genus—homo --species—sapiens Chimpanzees (our closest relative) is family Pongidae, although some researchers believe chimpanzees and humans should be in the same family and genus

A broad picture of our family tree

A look at our family tree

Once We Were Not Alone Paranthropus (Australopithicus) boisei, Homo rudolfensis, Homo habilis and Homo ergaster foraged in the same area around Lake Turkana. From “Once We Were Not Alone” by Ian Tattersall in Scientific American 2003

Human Skull evolution

Some distinguishing physical characteristics of humans Skull Features: • Flat face • Prominent Chin • Modified teeth • Large brain case (~1300 cc)—early hominids/chimpanzees ~450 cc • Reduced brow ridges • Smaller cheek bones Other skeletal features • Adapted for bipedal locomotion—changes in pelvis, foot

A Tour Through 7 Million Years of Human Evolution No clear fossil evidence of last common ancestor between the line that would lead to chimps and the line that would lead to modern humans has been found yet However, many other intermediates have been found. . .

African Ancestors

Sahelanthropus chadensis: About 7 million years old, status as human ancestor unclear

Ardipithecus: 4. 4 million years ago

Australopithecus afarensis: 3. 5 million years ago

Homo habilis: 2. 4 million years ago First clear use of stone tools

Homo erectus: 1. 8 million years ago

Relationship between modern humans, Neandertals, and Denisova

Neandertals: 350, 000 to 30, 000 bp Neandertal modern human

Gibraltar Child: A Neandertal Child

Modern humans: ~200, 000 years ago

What else have we learned from the Neandertal genome? 1. People from Eurasia share 1 -4% of their genomic variations with Neandertals: “It may not sound like a lot -- between 1 and 4 percent. But that's the equivalent of one great-great grandparent's DNA contribution. In the case of the Neandertal contribution, more than 1500 generations ago, it's an enduring legacy of an ancient group of people, spread across many lines of the genealogies of living people. ”--from John Hawk's (Associate Professor of Anthropology, U. of Wisconsin) weblog, May 6, 2010

2. Comparison of the modern human genome with the neandertal genome suggests that many human genes have been positively selected (relative to Neandertals) at 212 sites --genes involved in metabolism, neuronal and skeletal functions 3. So far, only 88 single amino acid changes have been found between the protein sets of modern humans and Neandertals

Various scenarios explaining presence of neandertal genomic traits in modern humans

Evolution in tool making

Homo habilis (Oldowan stone tool industry)

Early Homo georgicus (transition Between Homo habilis and Homo erectus) Stone tools from Dmanisi site and insitu fossil

Homo erectus

Trends in Brain Evolution http: //www. colorado. edu/intphys/Class/IPHY 3730/05 cns. html

Human Brain evolution

Recent Human Brain Evolution

Absolute Increase in brain volume http: //cas. bellarmine. edu/tietjen/Laboratories/Bio%20 Pix%204%20 U/Bio%20 Pix. htm

Brain evolution trends (brain mass to body mass ratio)

Virtual endocasts (red) and crania (transparent) of four hominid taxa in comparison to visualize the differences in shape and relative position. Comparison of the Taung child endocast with apes and man. A. Frontal lobe of an ape. B. Taung specimen (A. africanus). C. Frontal lobe of a human. The simplicity and what seems to show sulcal pattern shows that the Taung resembles the chimpanzee. Comparative cranial configuration of monkeys, chimpanzees, and man. A: Monkey B: Chimpanzee and C: Man

Human and chimpanzee brains Bradbury, molecular insights into human brain evolution, PLOS Biology (2005), Volume 3, Issue 3, 367

The variations between human and bonobo brains Three-dimensional reconstruction of a reference bonobo (pygmy chimpanzee) brain (A) and a reference human brain (B) after magnetic resonance imaging and normalisation of absolute brain sizes. The virtual bonobo brain has been transformed into the virtual human brain using an elastic deformation algorithm. The local deformation vectors are colour-coded and projected onto the virtual human brain (C). The most dramatic changes in brain shape occur in (1) the ventro-orbital prefrontal cortex, (2) the ventral stream of the visual cortex, and (3) the hypothalamic neuroendocrine region. Bradbury, molecular insights into human brain evolution, PLOS Biology (2005), Volume 3, Issue 3, 367

Why the increase in brain size? • • Consumption of meat Cooking Development of hunting Development of proto-language Increased social ability (cooperative living) Sexual selection General use (tool construction an use improvement helps overall survival—may require bigger brains)

Genes involved in brain evolution? • Microcephalin—mutations result in small brain size – Certain mutations found in about 70% of humans arrived in the human genome about 37, 000 years ago • ASPM—mutations result in small brain size Protein involved in spindle-formation (used during mitosis), so perhaps controls neuron division rate Certain variants found in a quarter of people, arose around 5800 years ago • Nde 1—mutations result in premature neuron differentiation (in other words, less neurons and smaller brains—in mice) • Glutamate dehydrogenase Bradbury, molecular insights into human brain evolution, PLOS Biology (2005), Volume 3, Issue 3, 367

Distribution of the haplogroup D variant of Microcephalin Evans et al. , Science 9 September 2005: Vol. 309. no. 5741, pp. 1717 - 1720

Introgression of Microcephalin Haplogroup D into modern human populations Modern humans out of Africa Neandertals 37, 000 years From Evans et al, http: //www. pnas. orgcgidoi 10. 1073 pnas. 0606966103

Questions about our genetic heritage that ancient DNA can help answer • How are modern humans (Homo sapiens) related to Neanderthals (Homo neanderthalensis)? – While it is unlikely that modern human evolved directly from Neanderthals, was there any interbreeding between modern humans and Neandertals? – Has the Neanderthal genome made any contribution to the genome of modern humans?

Noonan et al. suggest that the original Homo sapiens/Neandertal split took place 706, 000 years ago and there was no genetic mixing after that time Noonan et al , Science 314, 1113 (2006)

http: //www. mnh. si. edu/anthro/humanorigins/ha/a_tree. html

Neandertal modern human

Gibraltar Child

Neandertal flute?

Neandertal Hybrid ? Modern Human (Cro-Magnon) Erik Trinkaus (Washington University) thinks he has detected definite skeletal evidence of hybridization Published in PNAS, 2007

Trinkaus and team reported previously a possible hybrid on the Iberian peninsula in 1999 (Lagar-Velho 1)