Supplemental Lecture (99/12/29 update) by Stephen T. Abedon (abedon.1@osu.edu)

(1) Chapter title: The Evolution of Man

(a) An index to all of the vocabulary words found on this site also exists [index]

(2) Overview

(a) This page has been under development for quite some time as a part of the introductory biology course that I teach at the Ohio State University. It is meant to be an extension of the diversity of life material presented by Campbell (1996) in his introductory biology text. As will become abundantly clear upon observation of the presented table (below), I have gotten somewhat carried away. Nevertheless, what is presented is my current understanding of the evolutionary history of man.

(b) The table is a list of more or less nested clades going from the universal ancestor on down to Homo sapiens. Included with most categories are links to sites (e.g., The Tree of Life) providing additional information (though some supply more information than others).

(c) Note that not all of the named clades are commonly included in a formal taxonomic description of Homo sapiens, i.e., Domain, Kingdom, Phylum, Subphylum, Class, Order, Suborder, Superfamily, Family, Genus, and Species as Eucarya, Animalia, Chordata, Vertebrata, Mammalia, Primates, Anthropoidea, Hominoidea, Hominidae, Homo, and sapiens, respecitively, though those that are included (as just listed) are listed capitalized and without parentheses (formal taxonomic descriptions not commonly used formally with Homo sapiens are listed, instead, parenthetically and starting with lowercase). The problem, of course, is that formally recognized taxa are often paraphyletic and therefore (by definition) not true clades. Here I am making an attempt at listing and nesting all of the known, true clades that include humans, plus listing all fossil species that might be ancestral (with the caveat that many or all fossils are at best controversially ancestral).

(d) Note that I am not a paleobiologist but, instead, a bacteriophage ecologist (see: www.phage.org) so will no doubt have made numerous grave errors. Any help in correcting these errors, or embedding better links will be most appreciated.

(e) Additional material, some better than others, that I have provided elsewhere on the web can be found by clicking on the following links:

(i) origin of universe

(ii) history of Earth

(iii) brief introduction to biology

(iv) decent with modification: a Darwinian view of life (Campbell chapter outline)

(v) introduction to evolution

(vi) the evolution of populations (Campbell chapter outline)

(vii) evolutionary biology

(viii) population genetics

(ix) Hardy-Weinberg problems

(x) the origin of species (Campbell chapter outline)

(xi) speciation

(xii) tracing phylogeny: macroevolution, the fossil record, and systematics (Campbell chapter outline)

(xiii) classification of organisms

(xiv) early earth and the origin of life (Campbell chapter outline)

(xv) origin of the universe

(xvi) history of earth

(xvii) brief introduction to biology domains and kingdoms

(xviii) prokaryotes and the origins of metabolic diversity (Campbell chapter outline)

(xix) bacteria

(xx) archaeabacteria

(xxi) the origins of eukaryotic diversity (Campbell chapter outline)

(xxii) protozoa

(xxiii) algae

(xxiv) plants and the colonization of land (Campbell chapter outline)

(xxv) evolution of plants

(xxvi) reproduction by seed

(xxvii) fungi (Campbell chapter outline)

(xxviii) invertebrates and the origin of animal diversity (Campbell chapter outline)

(xxix) the vertebrate genealogy (Campbell chapter outline)

(xxx) ascent of mammals

(xxxi) descent of man

(3) Evolution of Man

Category	Taxon, Geological Age, etc.	Characteristics, Description, quote are from Campbell, 1996		First (mya) appearance
(?)	???	???		?
(cosmology)	universe	created by the big bang		~10,000
(cosmology)	milky way	our galaxy
(cosmology)	sun	our star, a.k.a., sol, created via the condensation of a large cloud of mostly hydrogen gas		~4600
(?)	earth	our planet, a.k.a., home, created by accretion		~4600
(?)	moon	our sister plant, created upon the collision of a Mars-size body with early plant earth		~4000
(?)	plate tectonics	the movement of continents across the face of the earth
(species?)	cellular root / univesal ancestor	a prokaryote [Carl Woese’s home page]		~3500
---	first oxygen pulse	"oxygen begins accumulating in atmosphere"		2200-1800
Domain	Eucarya	organisms with nuclei; 67% of Earth's history is already over		~1500
(kingdom)	Archezoa	eight-kingdom kingdom of eukaryotes lacking mitochondria		ditto
(domain)	Eubacteria	ancestor of endosymbiotic bacteria
(kingdom)	Protista	protozoa, single-celled eukaryotes (etc.) in five-kingdom system
(?)	mitochondrial eucaryotes	endosymbiont-containing eukaryotes
(kingdom)	Protista	protozoa, non-Chromista, non-Plantae, single-celled mitochondrial eucaryotes (eight-kingdom system)
(phylum)	Zoomastigophora	a.k.a., zooflagelata and mastigophora; flagellated mitochondrial protists
(?)	choanoflagellate	protist, possible animal (and fungi) ancestor
(?)	crown eucaryotes	animals, fungi, plants, etc.
Kingdom	Animalia	metazoans		~700
(subkingdom)	Eumetazoa	true body tissues		?
---	second oxygen pulse	"oxygen begins accumulating in atmosphere"		~600
(?)	Bilataria	animals with bilateral symmetry, triploblastic		?
(?)	coelomates	true body cavities; not true clade?		?
(?)	deuterostomes	animals with derived mouths		?
era	Paleozoic	Cambrian explosion; 87.5% of Earth's history is already over		570
Phylum	Chordata	tunicates, lancelets, fish		>530
period	Cambrian	"origin of most invertebrate phyla; diverse algae"		570
(?)	Craniata	animals with skulls: hagfish and vertebrates
	Hyperotreti	hagfish (primitive craniate)		?
period	Ordovician	"first vertebrates (jawless fishes); marine algae abundant"		510
Subphylum	Vertebrata	lampreys and jawed vertebrates
(super class)	Ostracoderms	extinct jawless vertebrates
(?)	Gnathostomata	vertebrates with jaws
(?)	Teleostomi	mouth terminal in position, narrow-based braincase, three otoliths in ear		?
period	Silurian	"diversity of jawless vertebrates; colonization of land by plants and arthropods; origin of vascular plants"		439
(class)	Osteichthyes	bony fish [transition from primitive fish to bony fish]
(subclass)	Sarcopterygii	fleshy-finned fish (lobe-finned & lung fish)
(order)	Crossopterygii	lobe-finned fishes
(order)	Rhipidistians	ancestral lobe-finned fish
period	Devonian	"diversification of bony fishes; first amphibians and insects"		408.5
(species)	???	footprints through muddy shallows on four feet (National Geographic, 5/99 issue)		365
(?)	tetrapods	terrestrial vertebrates (amphibians onward) [transition from primitive bony fish to amphibian (Talk.Origins)]		?
(?)	Anthrocosauria	???		?
period	Carboniferous	"extensive forests of vascular plants; first seed plants; origin of reptiles; amphibians and insects"		362.5
(?)	Amniota	reptiles and onward [transition from amphibians to amniotes (Talk.Origins)]		?
(?)	Synapsida	reptile branch giving rise to mammals [transition from reptiles to mammals (Talk.Origins)]
(?)	Eupelycosauria	???
(?)	Sphenacodontia	???
(?)	Sphenacodontoidea	???
(?)	Therapsida	mammals and extinct relatives
period	Permian	"radiation of reptiles; orgins of mammal-like reptiles and most modern orders of insects; extinction of many marine vertebrates"		290
era	Mesozoic	begins after Permian extinction		248.2
period	Triassic	"gymnosperms dominate landscape; first dinosaurs and mammals"		248.2
not ancestor	(dinosaurs)	(not ancestral to humans)		227.4
Class	Mammalia	hair and mammary glands		~220
period	Jurrassic	"gymnosperms continue as dominant plants; dinosaurs dominant; first birds"		205.7
period	Cretaceous	"flowering plants (angiosperms) appear; dinosaurs and many groups of organisms become extinct at end of period		144.2
(?)	Eutheria	placental mammals		~80 to ~100
(?)	primate-rodent complex	according to Campbell (1996) the primates are closely related to the rodents (form a clade?); I suspect that not everyone aggrees
Order	primates	nails, grasping digits, binocular vision
era	Cenozoic	begins after Cretaceous "crisis"; mass extinction, meteor		65
period	Tertiary			65
epoch	Paleocene	"major radiation of mammals, birds, and pollinating insects"		65
(?)	plesiadapids	“primate-like mammals… that may be ancestral to primates, or may be ‘cousins’ to primates” [primates (Talk.Origins)]		?
(suborder)	Prosimians	“premonkey” primates		?
Suborder	Anthropoidea	monkeys and apes		?
epoch	Eocene	"angiosperm dominance increases; further increases in mammalian diversity"		56.5
epoch	Oligocene	"origins of most modern mammalian orders, including apes"		35.4
Superfamily	Hominoidea	apes
epoch	Miocene	"continued radiation of mammals and angiosperms"		23.3
(species)	Proconsul africanus	“probably ancestral to all the later apes” [primates (Talk.Origins)]		?
(species)	???	chimpanzee-human-gorilla-organgutan-gibbon common ancestor		?
(genus)	Dryopithecus	“later ape probably ancestral to the great apes” [primates (Talk.Origins)]		?
(species)	???	chimpanzee-human-gorilla-orangutan common ancestor		~15?
(genus)	Kenyapithecus	“gave rise to the African great apes” [primates (Talk.Origins)]		~16?
(species)	???	chimpanzee-human-gorilla common ancestor		6 to 8
(species)	Kenyapithecus wickeri	possible post-gorilla ancestor		?
(species)	???	chimpanzee-human common ancestor		6 to 8
(?)	Hominini	(synonymous with Family Hominidae?) includes the following genera: Ardipithecus, Australopithecus, Homo, Paranthropus, and Praeanthropus (» Australopithecus afarensis) (Wood & Collard, 1999)
(species)	Ardipithecus ramidus			? 5 to 4
Family	Hominidae	upright-walking apes;
epoch	Pliocene	"apelike ancestors of humans appear"		5.2
(?)	Praeanthropus
(genus)	Australopithecus	small-brained, upright-walking apes; may include genus Paranthropus as well as early Homo; many if not all members were likely more arboreal than members of genus Homo (excluding H. habilis and H. rudolfensis)		? ~5
(species)	A. anamensis			5 to 4
(species)	A. afarensis	“Lucy” and her kin; a.k.a., Praeanthropus africanus		~4?
(species)	A. garhi	possible link between A. afarensis and H. habilis		3 to 2
(?)	“early Homo”	H. habilis and H. rudolfensis		2.4
(species)	H. habilis	“handy man”; may not have been first tool users; along with H. rudolfensis (2.4-1.8 mya), may not even be a legitimate member of genus Homo (Wood & Collard, 1999{4672}); extinct by 1.6 mya		2.3-1.9?
Genus	Homo	large-brained, upright-walking apes; minimally includes H. ergaster, H. heidelbergensis, H. neaderthalensis, H. sapiens and their varients		1.9
(species)	H. ergaster	possible alternative to H. erectus as post-H. habilis human ancestor; extinct 1.5 mya		1.9
(species)	H. erectus	fire, expanded tool kit, spread kind throughout world; extinct by 0.2 mya		~1.9
period	Quaternary			1.64
epoch	Pleistocene	"ice ages; humans appear"		1.64
(species)	H. antecessor	post-H. erectus / ergaster possible ancestor		~1.0
(?)	H. sapiens archaic	potentially more than one species		~0.5
(?)	H. sapiens “early moderns”	[hominid paleo-ethology unit (Universitat de Barcelona)]		~0.2
(?)	---	mitochondrial eve		0.4 to 0.1
epoch	Holocene			0.1
Species	sapiens	us	human pop. size	~0.1
culture	---	burial of dead	???	~0.1
species?	H. sapiens “Cro-Magnon”	anatomically modern H. sapiens	???	~0.05
culture	---	drawing and proto-writing	???	~0.03+
culture	---	civilization	5 million	~0.01
culture	---	writing	???	~0.005
culture	-384	Aristotle	~250 million	~0.002
culture	1215	Magna Carta	450 million	~0.001
culture	1650	---	500 million	~0.0004
culture	1776	Declaration of Independence	800 million (1750)	~0.0002
culture	1825	---	1 billion
culture	1903	heavier-than-air aircraft	1.6 billion	~0.0001
culture	1927	---	2 billion
culture	1940s	WWII & atomic bomb	2.3 billion (1945)	~0.00006
culture	1954	Brown vs. Board of Education	2.6 billion	~0.00005
culture	1960s	space travel & The Beatles	3 billion (1960)	~0.00004
culture	1970s	hand-held calculators	4 billion (1975)	~0.00003
culture	1980s	personal computers	5 billion (1985)	~0.00002
culture	1990s	www/internet	6 billion (1999)	~0.00001
culture	2000s	tenure???		~0.00000

(4) Footnotes

(a) (?) – parenthetic question marks in the first column mean that I am not aware of the level of the subsequent taxonomic category.

(b) ? – non-parenthetic question marks in the last column mean I am uncertain of the relative date (i.e., order of rows); when I am uncertain about absolute dates I leave the entry blank or employ a range.

(c) ??? – I don’t know/understand the information that belongs here.

(5) References

(a) Wood, B., Collard, M. (1999). The human genus. Science 284:65-71. “A general problem in biology is how to incorporate information about evolutionary history and adaptation into taxonomy. The problem is exemplified in attempts to define our own genus, Homo. Here conventional criteria for allocating fossil species to Homo are reviewed and are found to be either inappropriate or inoperable. We present a revised definition, based on verifiable criteria, for Homo and conclude that two species, Homo habilis and Homo rudolfensis, do not belong in the genus. The earliest taxon to satisfy the criteria if Homo ergaster, or early African Homo erectus, which currently appears in the fossil record at about 1.9 million years ago… We suggest that a fossil species be included in Homo only if it can be demonstrated that it (i) is more closely related to H. sapiens than it is to the australopiths, (ii) has an estimated body mass that is more similar to that of H. sapiens than to that of the australopiths, (iii) has reconstructed body proportions that match those of H. sapiens more closely than those of the australopiths, (iv) has a postcranial skeleton whose functional morphology is consistent with modern human-like obligate bipedalism and limited facility for climbing, (v) is equipped with teeth and jaws that are more similar in terms of relative size to those of modern humans than to those of the australopiths, and (vi) shows evidence for a modern human-like extended period of growth and development.” (Wood & Collard, 1999{4672}) Genus may be defined as: “In the first (evolutionary systematic) interpretation, a genus is a species or a group of species of common ancestry that occupies an ecological situation, or adaptive zone, that is different from that occupied by the species of another genus… In the second (cladistic) definition, a genus is a group of species that are more closely related to one another than to species assigned to another genus. Thus, this interpretation insists that a genus must be monophyletic; it cannot be paraphyletic… We suggest, therefer, that a genus be defined as a species, or monophylum, whose members occupy a single adaptive zone.”

(b) Zimmer, C. (1999). Fossils give glimpse of old mother lamprey. Science 286:1064-1065. “…two (530 mya) fossils represented different species, and although the fossils measured only a couple of centimeters long, the researchers could recognize key vertebrate traits. They had rows of gills, and their muscles were arranged in W-shaped blocks along their flanks, a pattern unique to vertebrates. ‘they were presumably filter feeders but they have these muscular bodies and things which we cautiously interpret as an eye… And so presumably they could go along at a fair pace if they had to, and they might have grabbed prey.” “The researchers then tried to find a place for the fossils in vertebrate evolution. A number of researchers believe that vertebrates evolved from an ancestor something like Amphioxus, otherwise known as the lancelet. Amphioxus, which lacks eyes or fins and looks rather like a miniature anchovy fillet, has a notochord—a primitive backbone. The first vertebrates added new traits to that body plan, such as a skull with a brain; later vertebrates acquired jaws and fins. The most primitive vertebrate alive today is the hagfish, a jawless fish, and the second-most primitive is the lamprey.” “…the fossils fall into a surprisingly advanced position. One of the species , which the researchers named Haikouichthys, is most closely related to the lamprey. The other fossil—tortuously named Mylokunmingia—is more primative (its gills are simpler), but… it is still a closer relative to us than to the hagfish.”

(c)