From Reptiles to Us

From Mbscientific_wiki

Biotic Morphogenesis - Reptiles to Homo Sapiens (a pictorial family album), the tree of life

In the last section we followed our pictorial family tree up to reptiles. We'll pick up the story from there. The stem species of reptiles, the Cotylosaurs appeared during the Pennsylvanian. During Permian era reptiles called Synapsids appeared, and established an evolutionary branch, leading to mammals.

In the transition from reptiles to mammals a major evolutionary morphological change occurred. The mammals became warm blooded. The main morphological change was to the circulatory system, it became efficient, as you can see below:

In the amphibian and reptile circulatory system a mix of oxygenated blood (in red) and deoxygenated blood (blue) feed the body capillaries (purple artery). In the bird and mammal circulatory system, only oxygenated blood feeds the body capillaries. And since oxygen is the main catalyst for metabolism (generation of internal energy), birds and mammals have plenty of it and can maintain a consistent body temperature regardless of the outside temperature. That means that they can be active all of the time and migrate to cold climates. This gave them the evolutionary edge over the reptiles and they flourished.

Reptiles to Placental Mammals

We will follow the branch of Synapsids, as pictorially shown:

1-Cotylosaurs (Pennsylvanian) - reptile stem species	2- Synapsids (Late Pennsylvanian - Permian)
3-Therapsids (Permian and Triassic)	4- Cynodont (Triassic)
5- Probainognathia (late Triassic, picture related Trithelodontidae)	6- Morganucodontidae (low Jurassic, picture related Megazostrodon)
7- Triconodonts (late jurasic-late cretaceous, picture related Gobiconodont)	8- Eutheria ( mid Cretaceous, picture related Xenarthra)

Morph Animation: morphing Cotylosaurs==> Therapsids ==> Gobiconodont (Triconodont)

The Eutheria (placental) mammal branch leads to the many familiar mammals that we see today:

Placental Mammals to Man

Of those branches, we are going to follow the one that leads to us, as pictorially depicted below:

1- Insectevora (late cretaceous, picture related Scandentia, late Paleocene, mid Eocene)	2- Primatomorpha (Eocene)
3- Plesiadapiformes: (Eocene)	4- Anthropoidea (mid Eocene, picture related Platyrrhini new world monkey)

Morph Animation: morphing Gobiconodont (Triconodont)==> Insectevora Scandentia==> Plesiadapiformes

Next, we'll follow the Hominid branch (src:http://anthropology.si.edu/humanorigins/ha/a_tree.html - Courtesy of Smithsonian Institute)-

But, as you might guess, I don't have artists renderings for all of them, so I'll put up all I could dig up:

5- Hominoidea: (apes. Gorilla, Homo, Hylobates, Pan, Pongo,) Range: from the Late Oligocene or Early Miocene; artist's rendering.	6- Sahelanthropus tchadensis(6-7 Million yrs, bipedal) Note: from 5 onwards, these are all artists' renderings. .
7- Australopithecus (5-4Myrs, bipedal)	8- Homo Habilis (2.5 Myr), Homo Erectus(1.3 Myrs), humorous artist's rendering!?!
9- Heidelbergensis (< 1 Myrs, Neanderthal pic. is closest thing I could find)	10- Us (well, me actually!)

Morph Animation: morphing Anthropoidea Platyrrhini==> Sahelanthropus tchadensis==> Australopithecus ==> Homo Sapien, Me

For a cool animation of hominid to human family tree click here

The Tree of Life - synopsis

Chapter Key: Morphological Flows, entities going through functional constructs thereby creating more complex entities with more complex functionalities:

Between comparing gene and protein sequences, comparative anatomy and studying the fossil record, the tree of life can be assembled (it is an evolving, US government funded, world wide collaborative work available at www.tolweb.org). A synopsis of what we covered pictorially is shown in the table below (follow the yellow brick road, branching in successive rows, till it gets to us - the white cells branch off to other life forms that may or may not be extinct - we don't follow the white branches - for that see tolweb.org):

Single cell primordial family:

Eukaryotes

Archaea

Eubacteria

?viruses, ? nanobes

Cell Colonies Animals (amoebae)

Cell Colonies Plants (green algae)

Fungi

Proteists

Etc.

Bilateria (mollusks, arthropods, vertebrates, etc.)

Cnidaria (jellyfish, anemones, corals)

Porifera (sponges)

Etc.

Deuterostomia (vertebrates, echinoderms, tunicates, etc.)

Arthropods (insects, crabs, etc.)

Mollusks (clams, snails, squid, octopus)

Annelids (segmented worms) , Flatworms

Etc.

Chordates (vertebrates and relatives)

Echinoderms (starfish, urchins, etc.)

etc.

Craniata (animals with sculls, hagfish, vertebrates)

Tunicates

Vertebrata (lampreys and jawed vertebrates)

Hagfish

Jawed Vertebrates

Lampreys

etc.

Lobed fin fish and 4 legged vertebrates

Ray-fin fishes

Sharks and rays

etc

Terrestrial vertebrates (mammals, birds, reptiles, amphibians

coelacanths

Other extinct relatives

Amniota (mammals, birds, reptiles, dinosaurs, etc.)

Amphibians (frogs, salamanders, etc.)

Extinct relatives

Etc.

Mammals

Reptiles, dinosaurs birds

Turtles

Etc.

Placental mammals

Platypus, Echidnas

Marsupials (opossums, kangaroos)

Primates (monkeys, lemurs, chimps, humans)

Rodents

Carnivora (dogs, cats, hyenas, bears, seals, walruses, etc.)

Cetacea (dolphins, whales, etc.)

Horses, tapirs, rhinos, etc.

Etc.

Humans, great apes, gibbons

New world monkeys

lemurs

Etc.

Human, gorilla, chimp, orangutan, etc.

gibbons

Old world monkeys

Hominids

Gorillas

Chimps

Etc.

Homo Sapiens

Australopithecus

Homo erectus

Homo habilis

Etc.

Us

Once you cover the tree of life, you might note that 6 major functionalities of micro-life that the DNA-RNA-Proteins engendered: metabolic, replication, structural, sensor-motor, signaling and communication, defense and immunity, remain as the drivers of macro-life in the quest for survival as well.

Moreover the markers of morphological flows that we noted in the first chapter, when we covered the Creation of Elementary Particles in the Cosmos, remain in tact:

1- You have attractor/repulsive forces as impetus for life forms, be it predator-pray relationships, sexual drivers, environmental niche (habitat) drivers, etc. The 6 major functionalities enumerate above emanate from and are manifestations of these primal forces.

2- The Chaotic Dynamics are in tact. Life tends to radiate in every which way. The stable entities that find a niche perpetuate, those who don't won't. That is the essence of natural selection.

3- The spectra of life, the tree of life, is full. From viruses and single cells, to various larger animals, to groups and colonies, to our societies, the spectra is full, even though speciation and die-offs go on. With the floor fixed, morphological flows push up the ceiling of complexity.

Courses

http://ocw.mit.edu/OcwWeb/Earth--Atmospheric--and-Planetary-Sciences/12-110Spring-2007/CourseHome/index.htm - MIT - 12.110 Sedimentary Geology - From MIT OpenCourseWare.

http://www.usd.edu/esci/vp/ - Vertebrate Paleontology (ESCI 463/563, ZOOL 486/586), Dr. Timothy Heaton, Department of Earth Sciences, University of South Dakota

http://ocw.mit.edu/OcwWeb/Materials-Science-and-Engineering/3-987Spring-2006/CourseHome/ - MIT - 3.987 Human Origins and Evolution. From MIT OpenCourseWare.

Chapter 6 QA Review

Links

http://www.ucmp.berkeley.edu/help/timeform.html - Geologic time

http://www.nationalgeographic.com/seamonsters/timeline/index.html?fs=plasma.nationalgeographic.com#introduction National Geographic Animated Time line 250-65 million years ago - Mesozoic Era's Triassic, Jurassic and Cretaceous Periods - a good one

http://www.ucmp.berkeley.edu/ - UC Berkeley Museum of Paleontology

http://geology.about.com/od/museums_paleo/See_Fossil_Exhibits_Online.htm - online paleontology museums

http://tolweb.org/tree?group=life - Tree of life

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/G/GeoEras.html - History of life

http://www.luc.edu/depts/biology/dev/devm.htm - Developmental biology

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html - A good online biology book

http://www.uwinnipeg.ca/%7Esimmons/Chap3298/sld001.htm - Animal evolution slideshow

http://www.cals.ncsu.edu:8050/course/ent425/tutorial/circulatory.html - Insect circulatory system

http://www.shadow.net/%7Ewweinkle/clamdissection.htm - Mollusk dissection- clam, see it then eat it

http://www.bio200.buffalo.edu/labs/echinoderms.html - Echinoderms- urchins.. ooh sushi, sake not included

http://www.animalnetwork.com/fish2/aqfm/1998/sep/wb/ - Flatworms

http://www.angelfire.com/de2/atoy/ - Earthworms

http://www.pbs.org/kcet/shapeoflife/episodes/index.html - PBS: Shape of life

http://www.pbs.org/wgbh/nova/link/clack2.html - More PBS: from fish to tetrapod

http://www.pbs.org/wgbh/nova/link/hist_nf.html - More PBS yet: a brief history of life.. I like PBS

http://www.gate.net/%7Erwms/EvoLimb.html - Evolution of Limbs from the Fossil Record and Molecular Biology

http://mac-huwis.lut.ac.uk/%7Ewis/lectures/limb-evolution/LimbEvolution.html Limb Evolution - comparative anatomy

http://www.biology.eku.edu/RITCHISO/342notes5.htm - Comparative vertebrate anatomy

http://www.mdgekko.com/devonian/site-index.html - Devonian Times

http://www.museums.org.za/iziko/index.html - South African Museum archives

http://palaeo.gly.bris.ac.uk/communication/boulton/Boulton.html - Dinosaur Evolution

http://www.txtwriter.com/Backgrounders/Dinosaurs/dinoBG2.html - Another Great Dinosaur evolution site

http://www.ansp.org/museum/dinohall/index.php - Academy of Natural Sciences Dinosaur Hall

http://www.nmnh.si.edu/vert/mammals/mammals.html - Smithsonian Museum

http://users.tamuk.edu/kfjab02/Biology/Mammalogy/biology_4429_ch_4a.htm - Mammalian Evolution

http://www.palaeos.com/Vertebrates/default.htm - Vertebrate Evolution, a great site

http://www.hunterian.gla.ac.uk/museum/hominid/hominid.html - Hominid evolution

http://anthro.palomar.edu/hominid/default.htm - Yet more Hominid evolution

http://www.mnh.si.edu/anthro/humanorigins/ha/a_tree.html - Hominid family tree from Smithsonian institute

http://news.nationalgeographic.com/news/2008/03/080310-hobbit-video-wc.html - VIDEO: Ancient Little People Found - Hobbits of Palau!

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