Linnaean Classification IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: Linnaean Classification Pongidae Hylobatidae Hominidae Apes = primates (grasping hands, binocular vision) with no tails

Phylogenetic Classification IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: Phylogenetic Classification 1-4% difference Hylobatidae Hominidae

IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: How can the small genetic difference account for the dramatic differences that occur between these species?

Homo sapiens Chimps, Gorillas Larger Head/body ratio smaller IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: 2. Patterns: a. Morphological and Behavioral Homo sapiens Chimps, Gorillas Larger Head/body ratio smaller Smaller jaw/head ratio larger Shorter limb/body ratio longer Less hair more hair Better learning poorer learning

Juvenile Primate Adult Primate Larger Head/body ratio smaller IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: 2. Patterns: a. Morphological and Behavioral Differences correlate with developmental differences Juvenile Primate Adult Primate Larger Head/body ratio smaller Smaller jaw/head ratio larger Shorter limb/body ratio longer Less hair more hair Better learning poorer learning

IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: 2. Patterns: a. Morphological and Behavioral Big head, short limbs Small head, long limbs

Primate Developmental Trajectory Chimp Human IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: 2. Patterns: a. Morphological and Behavioral b. Genetic Developmental genes can have profound effects on the final morphology of the organism. Primate Developmental Trajectory Chimp Human

What are some of these genetic differences? The HAR1 RNA molecule. IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: 2. Patterns: a. Morphological and Behavioral b. Genetic What are some of these genetic differences? The HAR1 RNA molecule. - not a coding RNA; probably regulatory - nearby genes associated with transcriptional regulation and neurodevelopment are upregulated in humans. - only 2 changes in sequence between chicks and chimps; 18 between chimps and humans. “HAR” stands for “human accelerated region” – changing more rapidly than drift can explain. why? Selection. Changes result in a profound change in RNA structure and, presumably, binding efficiency. Beniaminov A, Westhof E, and Krol A. 2008. Distinctive structures between chimpanzee and human in a brain noncoding RNA. RNA 14:1270-1275. Beniaminov A et al. RNA 2008;14:1270-1275

Sahelanthropus tchadensis IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: 2. Patterns: a. Morphological and Behavioral b. Genetic c. Fossils Chimpanzee Human Sahelanthropus tchadensis Sahelanthropus tchadensis – discovered in Chad in 2001. Dates to 6-7 mya. Only a skull. Is it on the human line? Is it bipedal? Probably not (foramen magnum). Primitive traits, as a common ancestor might have.

Ardipithecus ramidus: 4. 3-4. 5 mya Ardipithecus ramidus: 4.3-4.5 mya. Discovered in 1994 by Haile-Sailasse, Suwa, and White, with the most complete fossils were not described until 2009. Arboreal, but facultatively bipedal. Grasping toes.

Sahelanthropus tchadensis IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: 2. Patterns: a. Morphological and Behavioral b. Genetic c. Fossils Chimpanzee Human Homo sapiens Australopithecus afarensis Australopithecus africanus Homo habilis Homo erectus Sahelanthropus tchadensis

Innovation: Bipedality Radiation of Bipedal Hominids Competitive contraction?

Australopithecus afarensis: 2. 8-3. 9 mya Australopithecus afarensis: 2.8-3.9 mya. A femur discovered in 1973 by Donald Johansson suggested an upright gait, confirmed by his discovery in 1974 of the ‘Lucy” specimen. Also, the Laetoli prints (found by Mary Leakey) were probably made by A. afarensis, and in 2006, a juvenile A. afaresis was found.

Paranthropus aethiopicus: 2. 5-2 Paranthropus aethiopicus: 2.5-2.7 mya, discovered by Alan Walker and Richard Leakey, the “black skull” is one of the most imposing hominid fossils there is! Aside from the high cheekbones and the sagittal crest, it has similar proportions to A. afarensis and is probably a direct descendant. It probably gave rise to the “robust” lineage of Paranthropus.

Paranthropus boisei: 1. 2-2. 6 mya Paranthropus boisei: 1.2-2.6 mya. Discovered by Mary Leakey in Olduvai Gorge in 1959, it was originally classified as Zinjanthropus and nicknamed “Zinj” or “nutcracker man” because of the large grinding molars.

Paranthropus robustus: 1. 2-2. 0 mya Paranthropus robustus: 1.2-2.0 mya. Discovered in South Africa in 1938 by Robert Broom.

Competitive contraction? Innovation: Bipedality Radiation of Bipedal Hominids

Homo habilis: 1.4-2.3 mya, discovered by Louis and Mary Leakey, in association with stone tools. “Handy man”. Longer arms and smaller brain than other members of the genus.

Homo ergaster (H. erectus): 1. 3-1 Homo ergaster (H. erectus): 1.3-1.8 mya, the most complete fossil hominid skeleton was discovered in 1984 by Alan Walker who called it “Turkana Boy”. Some consider this species intermediate to H. habilis and H. heidelbergensis/H. sapiens, leaving H. erectus as a distinct Asian offshoot of the main line to H. sapiens. However, most paleontologists suggest that H. ergaster is the African ancestor – even a chronospecies or population - of H. erectus, which is ancestral to more recent Homo species.

Homo erectus: 0.2-1.8 mya; originating in Africa, but then leaving for Asia (Peking and Java Man). Discovered in Java by Eugene Dubois in 1891. Certainly one of the most successful hominid species in history; perhaps lasting as relictual species on islands in Indonesia as: Homo floresiensis: 94,000-13,000 years, discovered by Mike Mormood on the island of Flores. Shoulder anatomy is reminiscent of H. erectus, but could be an allometeric function of the small size (3 ft).

Homo neaderthalensis: 30,000-150,000; first discovered in 1829 Homo neaderthalensis: 30,000-150,000; first discovered in 1829. Descended from H. heidelbergensis. Homo sapiens idaltu: 160,000 – oldest Homo sapiens fossil – found in Africa in 2003… afar valley.

Competitive contraction? Innovation: Bipedality Radiation of Bipedal Hominids