Human Evolution Ch 17.6 “wolf book”
Human evolution is NOT controversial amongst most scientists BUT disagreements on: how many species. Interpretations of new finds diet, habitat, partially or fully upright. Human evolution should not be seen as a simple linear progression of improvement toward our own present-day form. You will see differences in evolutionary models.
About 220 million years ago The first mammal evolves
65-85 million years ago The first primates evolve
We belong to the Primate order along with lemurs, monkeys, chimps and apes! A.Primate Characteristics 1.Forward facing eyes: binocular vision: 3-D vision = jump/catch with accuracy 2.Flexible shoulder and hip: movement = swing, bipedal (makes taller/vantage point) 3.Bigger brains: complicated behavior, social, tools 4.Opposable thumbs: grasp, tools
25 million years ago Apes lineage separates from monkeys
15 million years ago Great apes separate from other primates Formation of family hominidae
10 million years ago Chimpanzee/ Human ancestor separates from gorilla ancestor
6-8 million years ago Human lineage separates from chimpanzee/b onobo ancestor Toumi – 7million year old fossil a possible common ancestor
4.4 million years ago Age of fossil Ardi
3.2 million years ago Age of fossil Lucy
million years ago The first members of genus Homo appear Significant increase in brain size
Which species do we come from? We really don’t know! Lots of fossils, but really hard to figure out which one gave rise to which
What We Think Many species overlapped, some left Africa earlier than homo sapiens did
What is the evidence? The oldest primate fossils are 55 million years old – few primate fossils have been found, far older primates may have existed The oldest hominin fossils are from Africa – Hominins include humans and extinct humanlike primates – Comparisons of human DNA with that of apes suggest that the two diverged between 5 and 8 million years ago
A. boisei A. africanus A. robustus H. erectus Australopithecus afarensis Sahelanthropus tchadensis Ardipithecus ramidus Orrorin tugenensis A. anamensis H. habilis Homo ergaster H. heidelbergensis H. sapiens H. neanderthalensis A Possible Evolutionary Trees for Humans