The Ancestor's Tale by Richard Dawkins -- Each Rendezous

In my original blog, which I deleted with one keystroke (the "delete" button") some time ago, I outlined the pilgrimage that Richard Dawkins described in his book, c. 2004.  That book is such an excellent book, both to read for pleasure as well as a reference book that I felt I had to restore that blog which I have done below.

This one book could be the textbook for advanced placement high school biology students looking to take a biology elective in their senior year, a year in which not much useful is accomplished by most seniors.

The Ancestor's Tale is a fantastic book and any biology teacher could have a field day using this as his/her text.

These are my notes for my use. If something seems incorrect, it is probably my error. Cross-reference the Dawkins text to answer questions. Some of the longer phrases are verbatim from the book and should not be used without referencing the source (Richard Dawkins).

 Notes from The Ancestor's Tale by Richard Dawkins

160,000 years ago

Herto humans in the Afar depression of Ethiopia
"Modern" or "nearly modern"
Herto humans clearly on the cusp between modern humans and predecessors

One million years ago

Archaic Homo sapiens: the Archaics

Immediate predecessors to "modern" humans
Lived alongside "modern" forms until at least 100,000 years ago
Even more recent, if we include Neanderthals
Examples: Heidelberg man, Rhodesian man, Dali man

1 million years ago to 250,000 years ago

Homo ergaster: the Ergasts
First fossil ancestor clearly different species than Homo sapiens
Unlike the Archaics, no overlapping features with Moderns
Bipedal
Campfires
Possibly could speak
Richard Leaky discovers Turkana Boy (1984); 1.5 myo

2 million years ago

Homo habilis: the Habilines
About as different from Ergasts as Ergasts from us
May include Homo rudolfensis; Kenyapithecus
Marks the place where brain starts to expand
Brain now beyond normal size of other large apes
Brain size why Habilines are Homo
Handyman

2.5 million years ago -- new discovery

Australopithecus sediba
Probably descendant of Lucy
April, 2010
Sediba: geographic location, south of Johannesburg
Professor Lee Berger, University of Witwatersrand
Sterkfontein region of South Africa near Johannesburg
"Cradle of Humanity"
Almost complete skeleton (actually composite)
May be identified as new species between Homo habilis and Australopithicus

4 million years ago

Australopithecus: Ape-men
Several species of hominids living alongside Homo
Homo's cousins include:

Australopithecus (Paranthropus) robustus
Australopithecus (Paranthropus, or Zinjanthropus) bosei
Australopithecus (Paranthropus) aethiopicus

Appeared to have evolved from "gracile" apes, not "robust" apes
Examples:

Mrs Ples
Mr Ples
Dear Boy (a robust australopithecine; "Zinj")
Little Foot
Lucy

Lucy, 3.2 million year ago

Donald Johanson
Australpithecus afarensis

Bipedal
Australopithecus anamensis, 4 million years ago

Rendezvous 1: 5 - 7 million years ago -- chimpanzees

First time our human ancestors meet another species
Actually two species
Chimpanzee and pygmy chimpanzee or bonobos
These two species split apart 2 mya
Was the Rift Valley that separated the Ape-Men from future hominids?

Rendezvous 2: 7 milion years ago -- gorillas

Continents looked pretty much like they do now
Mostly likely a knuckle-walker,  and tree-dweller

Rendezvous 3: 14 million years ago -- orang utans

Middle of the Miocene Epoch
About to enter its current cool phase, but still warmer than now
Originated in Africa or Asia; debates
Sivapithecus/Ramapithecus

Rendezvous 4: 18 million years ago -- gibbons

Early Miocene
Perhaps the finest arboreal acrobats that have ever lived
Second only to humans in the difficult art of walking upright
No tail; tree dweller

Rendezvous 5: 25 million years ago -- Old World monkeys

First time we enter a new period; leave Neogen; enter Palaeogene
The next time we enter a new period -- the Cretaceous world (dinosaurs)
Last stop on the backward journey where climate/vegetation still similar
Africa completely separated from rest of world
Huge sea between Africa and Spain
Two main groups of Old World monkeys
Colobus (Africa) and langurs and proboscis (Asia)
Macaques (mostly Asian) and baboons and guenons (Africa)
Concestor 5: probably looked like Aegyptopithecus
Tail: most likely, yes
Old World monkeys more closely related to apes than New World monkeys
Perhaps better to call Old World monkeys, "tailed apes"

Rendezvous 6: 40 million years ago -- New World monkeys

Concestor 6: the first anthropoid
Lush tropical forests; even Antarctica was partly green

Rendezvous 7: 58 million years ago -- tarsiers

Palaeocene Epoch
Haplorhines: the clade that unites anthropoids and tarsiers
No tapetum lucidum; so huge eyes instead for night vision
Where does Rendevous 7 take place? Not known
North America rich in early omomyid fossils of the right period
North America joined to Eurasia via Greenland at that time

Rendezvous 8: 63 million years ago -- lemurs and bushbabies

We join the rest of the primates traditionally called prosimians

Lemurs
Pottos
Bushbabies
Lorises

We are haplorhine pilgrims meeting our strepsirhine cousins
Of the living strepsirhines, majority are lemurs, Madagascar only

INTERMISSION

Rendezvous 8 was our last rendezvous "before" (in the backward journey) we burst through the 65-million-year barrier, the so-called K/T boundary
This boundary separates the Age of Mammals from the Age of Dinosaurs
The K/T was a watershed in the fortunes of mammals
With loss of dinosaurs, pressure on mammals released and they flourished
The catastrophe: a meteor?

Rendezvous 9: 70 million years ago -- colugos and tree shrews

Flowering of flowers has just begun; dinosaurs still around

Rendezvous 10: 75 million years ago -- rodents and rabbitkind

Once classified as rodents, rabbits now have their own order
Rabbits: Order Lagomorpha
Rodents: Order Rodentia
Rodents are one of hte great success stories of mammaldom

Rendezvous 11: 85 million years ago -- laurasiathreres

The hot-house world of the Upper Cretaceous
Diverse, miscellaneous bunch
Only one thing in common: they all come from old northern continent of Laurasia
Seven different orders

Pholidota (pangolins)
Carnivora (dogs, cats, hyenas, bears, weasels, seals, etc)
Perissodactyla (horses, tapirs and rhinos)
Cetartiodactyla (antelope, deer, cattle, camels, pigs, hippos, whales)
Microchiroptera (small bats)
Megachiroptera (relatively big bats)
Insectivora (moles, hedgehogs, and shrews -- but not the elephant shrews or tenrecs)

Rendezvous 12: 95 million years ago -- xenarthrans

Meet up in South America; recently torn away from Africa
Odd group of mammals: armadillos, sloths, anteaters
"Alien joints" -- stronger lumbar articulations to support digging

Rendezvous 13: 105 million years ago -- afrotheres

Afrotheres: the last placental mammals to join the pilgramage
Elephants, elephant shrews, dugongs and manatees, hydraxes, aardvarks (ant bears) and probably the tenrecs of Madagascar the the golden moles of southern Africa
The next pilgrims we will meet are far more distant cousins, the marsupials
Therefore, the Afrotheria are our most distant non-marsupial cousins.

Rendezvous 14: 140 million years ago -- marsupials

Marsupials join the placental mammals
At the base of the Cretacous, living in the shadow of the dinosaurs
The supercontinent Gondwana (SA, Antarctica, Africa and India) just starting to break up
A short-lived cold period
Only a few flowering plants in the temperate forests of coniferous trees and plains of ferns
Few pollinating insects
At this point, the group represented by a small insectivore greets the other great group of mammals, the marsupials.

Rendezvous 15: 180 million years ago -- monotremes

Half-monsoonal, half-arid world of the Lower Jurassic
Southern continent of Gondwana was still just about connected to the great northern continent of Laurasia -- the first time in our backward journey that we find all major land-masses collected into a contiguous "Pangaea."
Only three genera (collectively known as monotremes) join us:

Duckbilled platypus (Eastern Australia and Tasmania)
Short-beaked echidna (Australia and New Guinea)
Long-beaked echidna (highlands of New Guinea)

Monotreme: single hole -- anus, urinary tract and reproductive tract all empty into a single shared opening - the cloaca; eggs emerge from that cloaca
Discussion of "northern" mammals (almost all) and "southern" mammals (the monotremes)

INTERMISSION: uninterrupted gap back another 130 million unbroken years.

The longest gap yet between any two milestones, to Rendezvous 16 where we will meet an even larger band of pilgrams than our own, the sauropsids: reptiles and birds
Sauropsids: pretty much all vertebrates that lay large eggs with a waterproof shell on land
"Pretty much" because monotremes have already joined us and also lay that kind of egg
Ichthyosaurs, an exception: birth to live young

Rendezvous 16: 310 million years ago -- Sauropsids

Second half of the Carboniferous Period
Vast swamps of giant club moss trees in the tropics
Sauropsids: by far the largest contingent yet to join the group

Rendezvous 17: 340 million years ago -- Amphibians

Early Carboniferous Period
We amniotes (the name that unites mammals with reptiles and birds) meet amphibian cousins
Pangaea has not yet come together; northern and southern landmasses surrounded a pre-Tethys ocean
Climate probably something like today
Concestor 17 is the ancestor of all surviving tetrapods (we are lapsed tetrapods, as are birds, but we are all called tetrapods)
Three groups of amphibians joined before they met up with us:
Frogs and toads
Salamanders and newts
Caecilians (moist, legless burrowers or swimmers; look like earthworms or snakes)
Amphibians: (generally) live on land; always reproduce in water

Rendezvous 18: 417 million years ago -- lungfish

Warm and shallow seas of the Devonian-Silurian boundary
Concestor 18: a sarcopterygian, a lobefin fish, much more like a lungfish than a tetrapod
Ten species of lungfish today: South America (6) and Africa (4)
Lungfish quit evolving 200 million years ago
Lungfish: a "living fossil"

Rendezvous 19: 425 million years ago -- coelacanths

Plants were just beginning to colonize the land
Coral reefs were expanding
We meet one of the sparsest, most tenuous bands of pilgrims in this story
One one genus:  See Living Fossil: the Story of the Coelacanth, by Keith Thomson

Discovered in the catch of a South African trawler in 1938
Thought to have gone extinct before the dinosaurs

Devonian "Age of Fishes"

Rendezvous 20: 440 million years ago -- ray-finned fish

Earliest Silurian; southern ice cap left over from the cold Ordovician
Teleosts: the great success story among modern vertebrates
Prominent at many levels of underwater food chains, both fresh and salt water
"Ray" refers to fact that fins have a skeleton similar to a fan
They lack the fleshy lobe at the base ofeach fin -- eponym for the lobefin fish like coelacanths and Concestor 18
Ray-finned fish are mostly teleosts, as well as a few odds and ends including sturgeon and the paddlefish

Rendezvous 21: 460 million years ago -- sharks and their kin

Sharks, rays and other cartilaginous fish (chondrichthyans)
In the seas of the icy-cold and barren lands of the Middle Ordovician
Skeleton: cartilage; no bone

Rendezvous 22: 530 million years ago -- lampreys and hagfish

Pivotal messengers from the dawn of vertebrates

Rendezvous 23: 560 million years ago -- lancelets

Last time that Dawkins will suggest date as firm as this
Dating getting more and more difficult
Phylum Chordata

Renezvous 24: 565 million years ago (e) -- sea squirts

A chordate; doesn't swim
Not even faintly reminiscent of a fish -- but it has a larva that looks like a tadpole
Discussion of neoteny, the axolotl's tale: juveniles become sexually mature

Rendezvous 25: 590 mya +/- large margin or error -- ambulacrarians

First group of invertebrates to join us
Starfish, sea urchins, brittle stars and crinoids (sea lilies)
Phylum Echinodermata, the spiny-skinned ones
Also, in this group, now, a curious little worm called Xenoturbella
A highly degenerate bivalve mollusc, with affinities to cockles

Rendezvous 26: 590 mya +/- large moe -- protosomes

The biggest of all rendezvouses
Protostomes: the great bulk of of the pilgrimage of animals
Less and less hard support of fossils
Now: molecular rangefinding
Animal kingdom divided into two great subkingdoms

Deuterostomia
Protostomia

Deuterostomia (all pilgrims, including us, so far)
Protostomia: joined us at Rendezvous 26
Has to do with gastrulation (embryology)
Protostome: mouth first
Deuterostome: mouth second

Rendezvous 27: 630 mya -- acoelomorph flatworms

"Snowball Earth" -- 590 - 630 mya: debated
Some flatworms were not protostomes
All flatworms have in common: lack an anus; lack a coelom
Acoela and the Nemertodermatida: in this group

Rendezvous 28: >630 mya -- cnidarians

The "c" is silent: "nidarians"
Freshwater hydras and marine sea anemones, corals and jellyfish
Unlike the Bilateria, they are radially symmetrical about a central mouth
No obvious head, no front or rear, no left or right, only and up and down
Most distant cousins; some even thought to be plants 

Rendezvous 29: >630 mya -- ctenophores

Some of the most beautiful of all the animal pilgrims
Superficial resemblance led them to be wrongly classed as jellyfish

Rendezvous 30: >630 mya -- placozoans

Trichoplax adhaerens, the only known species in its entire phylum, the Placozoa
Looks like a multi-cellular amoeba

Rendezvous 31: >630 mya -- sponges

Sponges are the last pilgrims to join us who are members of the Metazoa, the truly multicellular animals
The  most primitive and the most unusual animals
Difficulty determining animal vs plants. BUT they are heterotrophs (use organic carbon for energy, not photosynthesis).
Essentially circular pumping tubes
All sponge cells are germ cells; potentially immortal and can become any type of sponge cell

Rendezvous 32: 900 mya -- choanoflagellates

Date based on molecular evidence
The first protozoans to join our pilgrimage
140 species

Rendezvous 33: >900 mya -- drips

Single-celled parasites known as either Mesomycetozoea or Ichthyosporea, mostly parasites of fish and other freshwater animals
Mesomycetozoea, the last to join us before the fungi join us
DRIP stands for the four genera that make up this group:

Dermocystidium
Rosette agent
Ichthyophonus
Psorospermium

Rosette agent: a commercially important parasite of salmon

Now formally named Sphaerothecum destruens

Another one has now been found: Rhinosporidium seeberi

A parasite of the human nose

Rendezvous 34: > 900 mya -- fungi

We are joined by the second of the three great multicellular kingdoms, the fungi
The third is the plants
Fungi more closely related molecularly to animals than to plants

Rendezvous 35: > 900 mya -- amoebozoans 

Amoeba proteus
Large enough to be seen without microscope
Includes three different groups of slime molds

Rendezvous 36: >900 mya -- plants

The third multicellular kingdom; the true lords of life

Rendezvous 37: ~ 2000 mya -- eukaryocytes

INTERMISSION: The Great Historic Rendezvous

A cataclysmic event: arguably the most decisive event in the history of life, which really was a rendezvous, literally a historic rendezvous that actually took place in the true, forward direction of history. This was the origin of the eukarotic (nucleated) cell: the high-tech,  miniature machine that is the microfoundation of all large-scale and complex life on this planet. To distinguish it from all the other metaphorical backwards rendezvous points, Dawkins calls it the Great Historic Rendezvous.

Rendezvous 38: > 2000 mya -- archaea

Formerly called Archaebacteria
Closer to us then Eubacteria

Rendezvous 39: > 2000 mya -- Eubacteria