Friday, June 21, 2024

Book 16: Geology And Evolution -- Completed

Undated. Not sure what book this came from. Started transcribing June 21, 2024.

Completed initial transcribing on October 18, 2024. This page needs a lot of formatting.

I still haven't finished taking notes on the book. Great book. 

Precambrian (formation of earth to the first period of the Phanerozoic Eon (visible life):

  • 4.6 billion years ago: formation of the earth


 So the "precambrian" includes two eons with NO LIFE and one EON with invisible life (Proterozoic)

Hadean: 4600 - 4000 mya

Archaean: 4000 - 2500 mya

Proterozoic: 2500 - 541 mya -- first life, but invisible.

 ********************

Phanerozoic: 540 mya -- present -- eon of visible life.

  • starts with the Cambrian explosion (first period in the Proterozoic Era in the Phanerozoic Eon.
  • begins just after Ediacara fauna -- perhaps straddles end of Proterozoic and very, very beginning of Proterozoic.

****************************
Cambrian Explosion

Scientific American

Cambrian Period / System

540 - 485 mya (one-half billion years ago)

There are only four eons:

  • Hadean: no eras
  • Archaean: four eras
  • Proterozoic: three eras  -- six periods
  • Phanerzoic: three eras

How to remember the eons:

  • Two eons: no life
  • Two eons: life --
    • one eon: early life; ends with ediacaran
    • second eon: visible life; begins with Cambrian

Proterozoic EON (early life)

Proterozoic: "early life"             EON
early life


Proterozoic -- "early life" -- three eras:

  • early: palaeo-proterozoic
  • middle: meso-proterozoic
  • late: neo-proterozoic -- ENDS WITH THE EDIACARAN

Then at end of "early life" -- end of EDIACARAN -- all of a sudden -- explosion of life -- THE CAMBBRIAN PERIOD -- the first of six periods in the Paleozoic Era

Right at end of Proterozoic eon and beginning of Phanerozoic era -- abundant evidence of life. Ediacaran.

The Ediacaran marks the first widespread appearance of complex multicellular fauna following the end of the Cryogenian global glaciation known as the Snowball Earth

But it was the Cambrian explosion that was most remarkable.

Three "dividing points" begin within a million years of each other:
    1) classic point -- trilobites and corals
        trilobites
        reef builders -- corals

    2) first appearance of a complex feeding burrow called Treptichnus pedium
       
first appearance: 542 mya
        earliest widespread complex trace fossil

    3) first appearance of a small, generally disarticulated, armoured form called "the small shelly fauna"

Phanerozoic EON (visible life)

Phanerozoic Eon: originally this was the eon of most interest to paleontologists but term fell out of favor. Paleontologists immediately went ot the "eras" and the "periods" (e.g., Paleozoic era and the first period, the Cambrian); the Mesozoic era and the three periods, Triassic, Jurassic, and Cretaceous

Paleozoic ERA -- age of fishes and reptiles

  • Cambrian period
  • Ordovician period
  • Silurian period
  • Devonian period
  • Carboniferous period
  • Permian period

Mesozoic ERA -- age of dinosaurs -- started with The Great Dying -- P-T ended 66 mya volcano, second greatest dying

  • Triassic period
  • Jurassic period
  • Cretaceous period

Cenozoic (tertiary) ERA --  started with the second greatest dying, the K-P; currently age of mammals; now age of man

  • Paleogene period
  • Neogene period
  • Quarternary period

********************************
Cambrian Explosion

Three "dividing points" begin within a million years of each other:

  • classic point -- trilobites and corals
    • trilobites
    • reef builders -- corals
  • first appearance of a complex feeding burrow called Treptichnus pedium
  • first appearance of a small, generally disarticulated, armoured form called "the small shelly fauna"
    • early skeletal fossils
    • somewhere between Ediacaran and Cambrian

Phanerozoic EON: originally eon of most interest to paleontologists but term falling out of favor.

Phanerozoic Eon: Visible Life

Three eras:

  • Paleozoic: explosion --> fishes -- reptiles --> dinosaurs
  • Mesozoic: age of dinosaurs
  • Cenozoic: us

Paleozoic:

  • begins with Cambrian explosion, then
  • Ordovician
  • Silurian -- one of two periods of FISH
  • Devonian -- one of two periods of FISH
  • Carboniferous --
  • ends with Permian -- ends with greatest extinction event ever!

Permian-Triassic: THE GREAT DYING -- 94% of all species died off, marine and land life

Mesozoic: 250 mya -- 66 ma

  • Triassic period
  • Jurassic period
  • Cretaceous period

************************
The Book Evolution, Steve Parker, Alice Roberts, c. 2015

560+ pages

  • Chapter 1: earliest life; p. 22 - 53 (31 pages)
  • Chapter 2: plants, p. 54 - beginning to present -- p. 97 (43 pages)
  • Chapter 3: invertebrates, p. 98 - 171 (73 pages)
  • Chapter 4: fishes and amphibians, p. 172 - 227 (155 pages)
  • Chapter 5: reptiles, p. 228 - p. 369 (141 pages)
  • Chapter 6: birds, pages 370 - 415 (45 pages)
  • Chapter 7: mammals, pages 416 - 559 (143 pages)

************************
End Of Cretaceous
The Impact
Cretaceous - Paleogene (periods)
Mesozoic - Cenozoic (eras)
The Die-Off: K-Pg (K-Pe)
Second Worst
[Worst: the Permian - Triassic]

Cretaceous: tertiary extinction / boundary

Cretaceous-Paleogene extinction / boundary: K-P line

Tertiary: obsolete term; encompassed most of the Paleogene / Neogene periods

  • therefore, K-T (Cretaceous-Tertiary)

66 mya: extinction

  • all non-avian dinosaurs
  • most marine life
  • eliminated 80% of all life
  • K-Pg (K-Pe) -- second only to Permian-Triassic extinction

**************************************
Trilobites

Paleozoic Era: the oldest era of the Phanerozoic EON

The trilobites first show up in the Cambrian Explosion -- completely die out at end of Permian -- so Trilobites DEFINE THE Paleozoic era -- had the six periods ... Cambrian to Permian
die out just before the Triassic (end of Mesozoic Era)
so, if you find a trilobite, you are in the Paleozoic Era -- first era of visible life, the Phanerozoic EON

Trilobites: seen in early Cambrian

  • ancestor unknown
  • many species evolved at beginning of the Paleozoic / Cambrian until they completely died out at end of Paleozoic/Permian

Paleozoic Era: bookends -- Cambrian / Permian

*************************
Arthropods

Five classes (?)

  • insects
  • arachnids
  • crustaceans
  • millipedes
  • centipedes

account for 80% of all animal species on earth

trilobites: just one class of arthropods

************************
Ecdysozoa

Ecdysozoa: supergroup -- shed all skin as they grow -- CHITIN

Ecdysozans: include nematodes and velvet worms.

Common ancestor of the Ecdysozan is UNKNOWN.

Arthropods:

  • chelicerata
  • myriapods
  • pancrustacea (includes insects)
  • (trilobites)

Molluscs: 100,000 species known; at least twice that number waiting to be discovered.

Only arthopods have more species than molluscs.

Molluscs:

  • slugs / snails (Gastropods: snails, slugs, conches, whelks, limpets -- largest group of molluscs -- 80% of all living species)
  • shellfish: clams, scallops, oysters
  • predatory: octopus, squid, cuttlefish

Date for the Ediacaran: neoproerozoic / late pre-Cambrian
so, Ediacaran: just before the Cambrian explosion

By middle Cambrian, most mollusc groups found in fossil record

So, Cambrian explosion: think molluscs -- slugs/snails; shellfish; predatory (octopus)

Gastropods: snails, slugs, conches, whelks, limpets -- largest group of molluscs -- 80% of all living species (of molluscs, I assume)

Then diagram:

Vertebrates: only 5% of all species.

Earliest fish:

  • appeared 480 mya
  • early ordovician
  • right after the Cambrian
  • Chordata:
    • bilaterally symmetrical
    • no backbone, but a notochord
    • cartilage "backbone" providing structure
    • row of gill openings
    • tail beyond the anus
    • segmented muscles as repeated groups

Chordates: broke into two groups --

  • vertebrates
  • tunicates and cephalochordates

Some suggest because lobopods resemble onychophorans (velvet worms) -- the lobopods (Hallucigenic, e.g.) may be ancestors of onychophorans.

Lobopodian morphologies in the Cambrian - multiple life forms -- maybe experimenting.

Some suggest the Lobopodia should be placed in an unranked paraphyletic taxon, Panarthropoda, comprising three phyla and one genus:

  • arthropoda
  • tardigrada
  • onychophora
  • and genus Thelxiope

************************
Animalia

Phyla: 36.

36 phyla but nine phyla contain the majority of described, extant species

Nine/thirty-six major phyla, to include

  • mollusca
  • porifera
  • cnidaria
  • platyhelminthes
  • nematoda
  • annelida
  • arthorpoda
  • echinodermata
  • chordata

****************************

Also: onychophora (see also lobopodia)

Ecdysozoa: molt, chitin

includes all animals that grow by ecdysis -- molting their exoskeleton

ecdysis: ancient Greek to take off; strip off.

****************************

Figure 3: Invertebrates

Animalia

Brittanica:

Phylum Arthropoda:

four subphyla of extant forms

  • Chelicerta (spiders)
  • Crustacea
  • Hexapoda (insects)
  • Myriapoda (centipedes and millipedes)

One extinct subphylum: trilobitamorpha

Wiki: >20 classes in phylum Arthropoda

Classes include insecta and arachnida

Phylum: body plan.

Class: major division in a phylum

Phylum: onychophora -- velvet worms

Phylum: arthropoda -- animals with jointed legs -- five classes
    Class: chelicerata (includes horseshoe crabs)
    Class: trilbita
    Class: crustacea
    Class: insecta
    Class: Myriapoda


Interesting: -- Fortey -- British -- calls these divisions classes -- whereas, it seems, most others call the five classes subphyla -- and then with five subphyla there are > 20 classes of arthropods.


Note: e.g., chelicerata is a subphylum

This is interesting: Fortey's jargon -- five major classes within phylum Arthropoda -- but it appears he takes largest class in each subphylum -- 

SUB-PHYLUM                            CLASS

Trilobitomorpha                        Trilobites (extinct)

Myriapoda

Chelicerata                                Arachnids                                                           
                                                  Horseshoe crabs


Hexapoda                                    Insecta


*********************


p. 42: velvet worm beginning to look as ancient as the horseshoe crab!!!

Best known onychophoran (velvet worms) from the Cambrian; Burgess Shale, BC, Canada

1977: Hallucigenia

Tardigrade --onychophoran -- arthropod -- velvet worm -- Aysheiai (extinct genus of soft-bodied lobopodian) -- on one really knows yet.

 

Back to onychophorans: extant velvet worms; then Aysheaia pedunculata (1911)

then hallucignia

 

So where does the story go from here? Seems to be two story lines: evidence of oldest animal and survivors ofall the mass extinction events.

p. 43: Fortey still comparing Aysheiai and Peripatus (velvet worms) --

Kerygmachela -- p. 45. Where do these all fit in tree of life??

Chitin would make articulated hinged joints a requirement; so closely related arthopods.

But velvet worms did not have chitin and hinges not possible; so we had teh non-articulated onychophoran and the articulated onychophorans (?).

Bottom line: Arthropods and Peripatus  (genus of velvet worms) --- common ancestor.


********************
Phanerzoic EON

Five major extinctions

In fact, there were dozens, but folks like to keep it manageable and five is a nice, small round number.

Three major extinctions: Paleozoic -- Ordovician-Silurian; end of Devonian; Permian-Triassic

Two major extinctions: Mesozoic -- at the end of the Triassic and end of Cretaceous

It looks like the Triassic involved in two mass extinctions:

  • first time: Permian-Triassic
  • second time: end of Triassic

****************

All those critters that appeared during the Cambrian -- most were by the end of the Paleozoic.

First extinction, but #2 in severity -- Ordovicia - Silurian -- 85% of marine species lost; not much on land to begin with.

Second extinction, relatively minor, Devonian (END of Devonian) -- almost only marine animals affected.

Third extinction, and this is the biggie -- the end of the Permian -- 96% of all marine species; 70% of all terrestrial species lost; "we" came close to losing it all!!! Followed by the Triassic.

Fourth extinction: end Triassic -- not much known about it -- again, mostly marine but land also hit hard; so two close together? third and fourth extinctions?

Fifth extinction -- end Cretaceous -- 65 mya -- loss of non-avian dinosaurs; allowed mammals to proliferate.

[Note: the 3rd extinction was preceded by a smaller -- but also huge CAPITANIAN extinction - the Capitanian is the latest subdivision of the Guadupian epoch which is the middle of the three epochs in the Permian.]




Sponges may have appears as long ago as 560 mya -- Ediacara fauna -- right before the Cambrian explosion, 540 - 550 mya.

Animal
    -- porifera (sponges) -- one branch
    -- eumetazoa -- the other branch

Dickinsonia: late pre-Cambrian; possible Placozoan
    -- maybe a halfway stage between sponges and Eumetazoa, animals with true tissues and specialized cells.

New discovery (2016): GK-PID.



This is so cool. Richard Dawkins was right on the cusp with sponges and then in 2016 -- the enzyme that connected the dots.



Placozoans:

should analysis be correct -- see wiki, also.

Trichoplax adhaevens -- wuld be the oldest branch of multicellular animals -- a relic of the Ediacara fauna -- or even the pre-Ediacaran fauna.


Some say only one living placozoan species -- others say three genera.

Phylum: Placozoa -- "flat animal"

Three named species:
    **** Tricoplax adhaerens **** -- said to be the world's simplest animal -- just a blog of cells
    Hoilungia honkongensis
    Polyplacotoma mediterranen

p. 201 - bony, juawless fish -- Bone: distinctive proof that all chordates descended from a common ancestor.

 

First bone probably dates from the late Cambrian!!

The story of AMPHIOXUS -- pp. 201 - 202. Lancelet at wiki.

Gills --> transformed --> moveable parts that became struts and levers of jaws -- the story of a Swede, Erik Stensio!!!!  p. 203. 

 

Jaws: two arches --

--- the mandibular arch -- forms the jaws themselves;
-- the hyoid arch -- acts as a support for the mandibular arch.

p. 204 -- moves to amphibians -- 

Unab le to come up with living species of amphibian surviving from the base of the tree of life. It is Fortey's major missing survivor. Today's amphibians all descended from a common ancestor long afger tetrapods crawled out of hte water. Most of them evolved after the great Permian Period mass extinction.

So, amphibians evolved twice.

So, great question / essay for students: following each of the 5 great mass extinctions, what resulted?

Only one "ancestor" -- from the Permian age fossil "ancestor" -- all frogs, toads, newts, salamanders, and relatives from one ancestor: all are in one group -- Lissamphibia.

Reptiles:

  • turtles
  • tuataras
  • a few lizards
  • crocs / alligators

Reptilian survivor:

The tuatara (sphenodon) superficially unchanged since the Triassic -- New Zealand -- two species of Sphenodon. Tuatara at wiki.

First fossils recognized as reptiles: CARBONIFEROUS -- remote second cousins of the tuataras (New Zealand)

Bay of Funday -- p. 210

Hylonomus

reptiles: "egg-laying animals." -- p. 211

Most did not survive the Cretaceous extinction but some did (the Cretaceous extinction event that wiped out the dinosaurs).

Huge extinct turtle: Archelon -- end of Cretaceous.

Carboneferous (Mississippian, Pennsylvanian)

20-million year gap: Romer's Gap; wiki entry here.

360 mya - 290 mya (70 million years)

After the gap -- wide diversity of fauna -- must have been a major radiation of species

 

Earliest Tetrapods seen in Devonian -- fish iwth legs.

After Romer's gap -- true land-based tetrapods.

East Kirkton, Scotland, world's oldest-known vertebrate terrestrial community.

Temnospondyls: first appears here; amphibian (one time thought to be reptilian)

Lepospondyls also present (legless amphibia; resembled sharks)

most striking: reptile-like animals also diapsids.

Crocs and alligators; p. 213

Chapter 8: Heat In The Blood

Shelled eggs required three new membranes (and ample yolk(.

Three new membranes:
chorion
amnion
allatois

Mammals dispensed with the shell -- developed tissue (PLACENTA) that could interact directly with the three new membranes.

Monotremes: egg-laying mammals.
Echidnas
Platypus

Echidnus -- four species in Australia and New Guinea

The last species to be discovered in the New Guinea highlands: 1961 -- a grand total of five species in all.

Many reptilian traits, including their body temp of 31 - 33°C, the lowest operating temp in Mammalia.

Echidan and relatives lived during age of Dinosaurs.

10-cm long Megazostradon -- mammal -- traces back to Triassic. Wiki entry here.

First seen 200 mya -- mid-Jurassic.

Mammals pretty much began due to richness of insect niche!!


The trick of "internal fire" -- p. 230 -- Birds and Mammals.

Lianas

Epiphytes

Having found a mammal survivor -- the echidna -- now the author looks for an avian survivor -- p. 230 -- 

Andes, Ecuador --

Avian survivor -- p. 234

 

Tinamous (plural) -- singular tinamou --

most primitive living bird

Tinamous and ratites = Palaeognatha: "old jaws"

Molecular studies:

tinamous and ratites: in a single group

--> Kiwis

--> the rest

 Now conventional: birds descended from lightly-built therapod dinosaurs with relatively long arms. 

Feathers likely colorful.

The dodo was not a ratite. The dodo was a giant, flightless dove.

Archaeopteryx --> tinamou somewhere in here -->

Birds survived the Cretaceous extinction which eliminated all their non-avian relatives.

Living birds, could be argues, are the most successful living vertebrates -- perching birds (passerines) more than twice as many species as the most diverse of the mammal groups -- the rodents.

Warm Blood

Warm blood unites creatures with fur and creatures with feathers.

Birds as a whole: survivors.

"Remember: of the major groups, amphibians alone -- according to Fortey -- have no example of a survivor.]

Enantiornithines -- p. 241.

p. 245 .. hmmmm? Fortey -- amphibians -- no survivor found.

The Mallorcan midwife toad (Alytes muletensis] "a living fossil" -- wiki entry here.

Earlier in the book he seemed to equate "living fossil" with survivor --p. 245.

Possible that the ferreret is at the junction between frogs and toads.

The Majorcan midwife toad (Alytes muletensis) (also Mallorcan midwife toad or ferreret in Balearic Catalan and Spanish) is a frog in the family Alytidae (formerly Discoglossidae). It is endemic to the Balearic Island of Majorca in the Mediterranean Sea. An example of Lazarus taxon, the species was first described from fossil remains in 1977, but living animals were discovered in 1979.
The Mallorcan Midwife Toad lives only on the island of Mallorca in Spain in the Sierra Tramuntana. The frogs live in streams carved into limestone mountains. Interestingly, the toad was originally discovered from a fossil and then after a few years, the first living ones were found. Link here.


 

Chapter 9

Islands, Ice

Begins about 100,000 years ago;

glacial

our own species emerged.

City of Las Palmas on the Mediterranean island of Mallorca.

The Mallorcan midwife toad also called a ferreret.

 

Balearic Islands: in the Mediterranean off Spain --
Mallorca
Menorca
Ibiza
Formentera

 

Three periods in the Cenozoic Era in the Phanerozoic Eon.

  • Paleogene: 65 - 24 mya
  • Neogene: 24 - 3 mya
  • Quaternary 3 mya - present



 


 





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