HUMAN - HUMAN EVOLUTION. Darwin & Human evolution. But . the . only. mention of human evolution in

  • View
    0

  • Download
    0

Embed Size (px)

Text of HUMAN - HUMAN EVOLUTION. Darwin & Human evolution. But . the . only. mention of human evolution in

  • HUMAN

    Where did we come from?

    www.christs.cam.ac.uk/darwin200

    EVOLUTION

  • HUMAN EVOLUTION Darwin & Human evolution

    Darwin was very aware of the implications his theory had for humans.

    He saw monkeys during the Beagle voyage but saw his first Ape at London Zoo.

  • Darwin first saw Jenny the Orang-utan in 1838; He recognized human-like qualities in her

    HUMAN EVOLUTION Darwin & Human evolution

    Darwin was very aware of the implications his theory had for humans.

    He saw monkeys during the Beagle voyage but saw his first Ape at London Zoo.

  • Darwin first saw Jenny the Orang-utan in 1838; He recognized human-like qualities in her

    Even Queen Victoria recognized the similarities:

    HUMAN EVOLUTION Darwin & Human evolution

    Darwin was very aware of the implications his theory had for humans.

    He saw monkeys during the Beagle voyage but saw his first Ape at London Zoo.

    “frightful and painfully and disagreeably human.”

  • HUMAN EVOLUTION Darwin & Human evolution

    But the only mention of human evolution in On the Origin of Species (1859) was:

    “Light will be thrown on the origin of man and his history”

    Darwin left people to figure it out the implications of his work themselves

  • HUMAN EVOLUTION Darwin & Human evolution

    He later dealt with the topic more thoroughly in The Descent of Man (1871)

    • comparisons between apes & humans reveal their shared ancestry

    • Darwin also showed all human races were one species (which was debated at the time)

    • Also outlined his theory of sexual selection

  • HUMAN EVOLUTION

    sapiens

    Homo

    Hominidae

    Primates

    Mammalia

    Chordata

    Animalia

    Eukaryota

    Human classification

  • HUMAN EVOLUTION

    sapiens

    Homo

    Hominidae

    Primates

    Mammalia

    Chordata

    Animalia

    Eukaryota

    Human classification Characteristic features:

    “thinking man”

    Man: bipedal

    The apes; no tails, larger bodies

    Large brains, stereoscopic vision

    Have mammary glands

    Develop dorsal nerve cord

    Multicellular, heterotrophic, no cell walls

    Cells with membrane bound nucleus

  • HUMAN EVOLUTION

    Humans are primates.

    Primates are distinguished from other mammals by:

    · greater reliance on vision than smell

    · shortened snout

    · grasping hands & feet

    · nails instead of claws

    · large brains relative to body size

    What are the main characteristics of primates?

    http://upload.wikimedia.org/wikipedia/commons/e/ec/Pdiadema_AGrandidier.jpg�

  • HUMAN EVOLUTION What are the main characteristics of primates?

    Primates evolved 70-80 million years ago. There are about 600 living species.

    25% are endangered!

    Humans are primates.

    Primates are distinguished from other mammals by:

    · greater reliance on vision than smell

    · shortened snout

    · grasping hands & feet

    · nails instead of claws

    · large brains relative to body size

    http://upload.wikimedia.org/wikipedia/commons/e/ec/Pdiadema_AGrandidier.jpg�

  • HUMAN EVOLUTION You are here

    The primate family tree

    Ring tailed lemur

    Tariser

    Slow Loris

    Woolly monkey

    Mandrill

    Gorilla

    http://upload.wikimedia.org/wikipedia/commons/b/b9/%E5%8C%97%E4%BA%AC%E5%8A%A8%E7%89%A9%E5%9B%AD%E7%9A%84%E5%B1%B1%E9%AD%88.jpg� http://upload.wikimedia.org/wikipedia/commons/1/12/Lemur_CinZoo_036.jpg� http://upload.wikimedia.org/wikipedia/commons/2/2b/Philippine_sarangani_tarsier.jpg� http://upload.wikimedia.org/wikipedia/commons/f/ff/Loris_paresseux_retouch.jpg� http://upload.wikimedia.org/wikipedia/commons/7/7b/Lagothrix_lagotricha.jpg� http://upload.wikimedia.org/wikipedia/commons/4/41/Gorilla_019.jpg�

  • HUMAN EVOLUTION The Apes

    Humans Homo

    Orang-utan Pongo

    Chimpanzees Pan

    Gibbons Hylobatidae

    Gorillas Gorilla

    Who is more closely related to who?

  • HUMAN EVOLUTION The Apes

  • HUMAN EVOLUTION The Apes

  • HUMAN EVOLUTION The Apes

  • HUMAN EVOLUTION The Apes

    Which is more closely related to chimpanzees:

    humans or gorillas?

  • HUMAN EVOLUTION The Apes

    Which is more closely related to chimpanzees:

    HUMANS!

    This grouping is supported by

    anatomical and DNA evidence

  • HUMAN EVOLUTION How do humans and chimpanzees differ?

  • HUMAN EVOLUTION

    Brain size Body hair

    Face length Locomotion

    How do humans and chimpanzees differ?

  • HUMAN EVOLUTION

    Brain size Body hair

    Face length Locomotion

    How do humans and chimpanzees differ?

    Brain size 1300-1400g 400g Body hair not much quite a bit Face length shorter longer Locomotion bipedal knuckle walking

  • HUMAN EVOLUTION

    5-7 million years ago5-7 million years ago

    virtually no chimpanzee fossils

    Lots of hominid (human ancestor)

    fossils

    How did these difference evolve? Evidence from fossils

    The human fossil record is quite good – about 20 species are recognised. The chimpanzee fossil record is very poor.

  • HUMAN EVOLUTION

    Paleo-anthropologists don’t always agree on the proposed relationships among the early human ancestors

    But we can recognize general trends

    The human fossil record

  • HUMAN EVOLUTION

    There was not a directed, gradual progression but instead a mosaic pattern

    The human fossil record

  • HUMAN EVOLUTION

    Increase in brain size

    Evolution Bipedalism

    Reduction in face more gradual

    The human fossil record

  • HUMAN EVOLUTION The human fossil record

    http://upload.wikimedia.org/wikipedia/commons/e/e9/SkullFromTheFront.JPG� http://upload.wikimedia.org/wikipedia/commons/6/63/Broken_Hill_Skull_(Replica01).jpg� http://upload.wikimedia.org/wikipedia/commons/4/45/Homo_habilis-KNM_ER_1813.jpg� http://commons.wikimedia.org/wiki/File:Australopithecusafarensis_reconstruction.jpg�

  • HUMAN EVOLUTION

    Increase in brain size

    Bipedalism

    Reduction in face more gradual

    The human fossil record

  • HUMAN EVOLUTION

    Darwin predicted this long before man’s African origins were established:

    “In each great region of the world the living mammals are closely related to the extinct species of the same region. It is therefore probable that Africa was formerly inhabited by extinct apes closely allied to the gorilla and chimpanzee; and as these two species are now man’s nearest allies, it is somewhat more probable that our early progenitors lived on the African continent than elsewhere. -Darwin (1871) The Descent of Man

    Modern humans evolved in Africa

  • HUMAN EVOLUTION Modern humans evolved in Africa

    The oldest known fossils of anatomically modern humans were found in Ethiopia from about 150,000 years ago

    http://upload.wikimedia.org/wikipedia/commons/2/27/Herto,_Ethiopia_;_Homo_sapiens_idaltu_1997_discovery_map.png�

  • HUMAN EVOLUTION Modern humans evolved in Africa

    The oldest known fossils of anatomically modern humans were found in Ethiopia from about 150,000 years ago

    Most scientists agree Homo sapiens evolved in Africa and migrated out from this single origin

    http://upload.wikimedia.org/wikipedia/commons/2/27/Herto,_Ethiopia_;_Homo_sapiens_idaltu_1997_discovery_map.png� http://upload.wikimedia.org/wikipedia/commons/3/37/Map-of-human-migrations.jpg�

  • HUMAN EVOLUTION Modern humans evolved in Africa

    Most scientists agree Homo sapiens evolved in Africa and migrated out from this single origin

    This is supported by genetic and phenotypic evidence. The diversity of both decrease with over-land distance from Africa.

    This is what would be expected if humans evolved once and their range expanded, going through a series of population bottlenecks

    http://upload.wikimedia.org/wikipedia/commons/3/37/Map-of-human-migrations.jpg�

  • HUMAN EVOLUTION What does the DNA evidence say?

    Scientists have now sequenced the genome of a: • Human • Chimpanzee • Gorilla • Orang-utan • Gibbon • Macaque (an old world monkey) • Marmoset (a new world monkey) • and a type of galago and a lemur As well as many other mammals!

    The DNA evidence confirms the relationships between humans, primates and other mammals.

    They show how similar we are, genetically, to chimpanzees: • an estimated 96-98% of our DNA sequence is identical to chimpanzees • (but that’s still millions of differences!)

  • HUMAN EVOLUTION What does the DNA evidence say?

    By comparing the DNA sequences biologists can see which regions of the genome have changed rapidly since the human-chimpanzee split.

    These studies highlight genes involved in: • immunity & defence – evolving to tackle new diseases as humans spread • dig