Download Basic Baupläne—Architectural Styles of the Biosphere

Basic Baupläne—Architectural Styles of the Biosphere
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Ernst Heinrich Philipp August Haeckel (18341919)
o 19th century proponent of
Darwinian evolution
o Obtained doctorate in medicine
1858, then pursued natural history,
purportedly because he was
influenced by Darwin’s Origin of
Species.
o Field expeditions included
Mediterranean (1859-1860),
Canary Islands (1866-1867), Red
Sea (1873), Ceylon (1881-1882),
and Java (1900-1901)
o Professor of zoology at Jena
(1865-1909)
o A true systematist, he described
over 4000 species of lower marine
taxa, including: Radiolaria (1862)
Siphonophora (1869), Monera
(1870) and Calcareous Sponges
(1872), as well as several
Challenger reports, viz. Deep-Sea Medusae (1881), Siphonophora (1888),
Deep-Sea Keratosa (1889) and Radiolaria (1887).
o Developed concepts of ecology, phylum, phylogeny, recapitulation, and the
first “tree of life”
o Work used as pseudoscientific basis for support of Nazism.
o Postulated ascent of man from Indonesian ancestor
o Fraudulent use of embryo images of dog and human woodcuts to support
Darwinian evolution
o Wrote Allgemeine Entwicklung der Organismus (1866) which included tree of
life.
ONTOGENY = “onto development”. Development of individual from conception
through death
o Includes changes in form, physiology, metabolism, function, and behavior
o Types of maturity include PHYSICAL, SEXUAL, and ETHOLOGICAL
o Maturity levels typically onset at different times
o Ultimate end of development in many species is sexual maturity
 “Cost of sex….”
PHYLOGENY = “phylo development”.Development of changes in organisms through
an ancestor—descendant lineage.
o Includes changes in form, physiology, metabolism, function, and behaviour
o May reflect ontogeny and embryological development
© WB Leatham 2006
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PAEDOMORPHIC evolution
 Retention of juvenile characteristics into maturity
o Can include NEOTENY (slowing of physical maturation),
PROGENESIS (halting of development prior to full
physical maturity), or POSTDISPLACEMENT (start of
development is delayed)
 PERAMORPHIC evolution
 Development of new characteristics after sexual maturity—
opposite of PAEDOMORPHOSIS
 Implicit in tree of life and increasing morphological complexity
 Certain organisms preferentially exhibit PERAMORPHOSIS (e.g.
ammonoids)
Developmental benchmarks
o BINARY FISSION
o GENE-STREAMING
o MEIOSIS (production and recombination of gametes to form zygote)
o ZYGOTE→CYTULA→BLASTULA→GASTRULA
 ZYGOTE = fertilized egg
 CYTULA = initial bound set of cleaved cells
 BLASTULA = hollow ball of cells which are TOTIPOTENT
 TOTIPOTENT = having total potential outcome
 GASTRULA = invaginated blastula (pre- pluripotent)
 PLURIPOTENT = having more than one potential outcome. Often
called stem cells that can differentiate into type of body tissues
o Cell cleavage controls morphological development
 Direction of mitosis controls shape of “colony” of cells
o Eukaryotic cell cleavage (early ontogeny)
 During mitosis, cellular cytoskeletal filaments (i.e. the MITOTIC
SPINDLE) of direct the segregation of the chromosomes. The spindle is
bound at the ends (poles) and its microtubles spread out towards the
equator. The spindle is made of structural proteins including Lamin-B,
a protein similar to Keratin. This spindle controls CYTOKINESIS, or the
division of the cell (= cleavage).
 SPIRAL CLEAVAGE
 Cleavage is oblique to the polar axis (axis of mitotic spindle).
Results in spiral pattern of cellular layers. Cells are fit between
tops of cells in layer one. Similar to hexagonal packing in
crystalline solids.
 Typical SPIRALLIANS include Arthropoda and Mollusca.
o Both are SCHIZOCOELIC.
 RADIAL CLEAVAGE
 Cleavage is either parallel or orthogonal to the polar axis (axis
of mitotic spindle). Results in parallel and orthogonal stacked
layers of cells. Similar to cubic packing in crystalline solids.
© WB Leatham 2006
o TOTIPOTENT cells form blastula, PLURIPOTENT cells then differentiate into
tissues (GERM-LEVEL differentiation) during GASTRULATION
 Phased cell division = TISSUE GRADE organism
 Three primary germ tissues:
 ECTODERM forms from the cells coating the gastrula.
Essentially epidermis (skin, etc.).
 ENDODERM forms from invaginated gastrular cells. Includes
mouth, esophagus, interior stomach lining, gastrointestinal
tract, respiratory pathways, anus, etc.)
 MESODERM forms between endoderm and ectoderm from
gastrular cells (pluripotent). Includes muscle, bone, blood,
and urogenital tissues.
 Production of COELOM (i.e. body cavity(ies))
 Mouth or anus forms from BLASTOPORE
Major Baupläne
NONCELLULAR
UNICELLULAR
DIPLOBLASTIC
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Nucleic acid
Artificial
PROKARYOTIC
EUKARYOTIC
Colonial/Parazoal
All have ENDODERM, MESOGLEA, ECTODERM, and POCKET GUT or
ENTERON
TRIPLOBLASTIC 
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All have endoderm, mesoderm, ectoderm, may have either a
BOTTLE GUT or THROUGH GUT
Classified based on COELOM (# and size)
o Two major methods of coelomic formation, controlled by ontogeny:
1. SCHIZOCOELY (mesodermal splitting)
2. ENTEROCOELY (out-pouching of endoderm)
Types of triploblastic organisms
ACOELOMATE
PSEUDOCOELOMATE
METAMEROUS COELOMATE
PSEUDOMETAMEROUS COELOMATE
OLIGOMEROUS COELOMATE
© WB Leatham 2006
o Typical body cavities have separate functions, e.g. brain cavity,
cardiopulmonary cavity, gastrointestinal cavity, reproductive cavity.
 ACOELOMATE (= without COELOM). Includes Platyhelminthes,
Nematodes, and several small phyla.
 PSEUDO COELOMATE (= false COELOM). Includes
 METAMEROUS COELOMATE (= multiple segmented COELOM). Includes
Arthropoda and Annelida.
 PSEUDOMETAMEROUS COELOMATE (= false multiply segmented
COELOM). Includes Mollusca.
 OLIGOMEROUS COELOMATE (= few segmented COELOM). Includes
Chordates, Chaetognaths, Echinodermata.
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Karl Grobben (1854-1945)
o Austrian invertebrate zoologist (mollusks and crustaceans) and Professor at
University of Vienna
o Developed developmental/classification concepts of PROTOSTOME and
DEUTEROSTOME (1908).
 PROTOSTOME (greek = “before the mouth”)
 BLASTOPORE (first formed opening) becomes the mouth
 Includes most BILATERIA
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 Deuterostome (greek = “second mouth”)
 Blastopore (first formed opening) becomes the anus
 Includes the following bilateral phyla:
o Chordata, Echinodermata, Hemichordata, and
Chaetognatha, and the extinct phylum Vetulicolia (Shu
et al, 2001).
 All are ENTEROCOELIC
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Berthold Hatschek (1854-1941)
o Czech-Austrian Invertebrate Zoologist
o developed concept of the TROCHOPHORa (Molluska and Annelida), based on
similarity of larval form (1878).
o TROCHOPHORE (greek = hair bearer). A larval form that is polar and has
several transverse rows of cilia.
o Developed concept of BILATERIA (1888)
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ASTOGENY controls populations of individuals
© WB Leatham 2006