The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the...
Transcript of The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the...
![Page 1: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/1.jpg)
Bio 100 - Study Guide 18
The Evolution of Animal Diversity
![Page 2: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/2.jpg)
Overview: Welcome to Your KingdomLearning Objectives
• Characteristics of Animals
• Origin of the Animal Kingdom
• Symmetry
• Segmentation
• Characteristics of Chordates….Vertebrates
• Phylogeny of the Animal Kingdom
![Page 3: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/3.jpg)
Characteristics of Animals-Learning Nutritional Mode
• Animals are heterotrophs that ingest their food
https://www.msu.edu/course/isb/202/ebertmay/notes/inotes/01_25_07_carbon.html
![Page 4: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/4.jpg)
Cell Structure and Specialization
• Animals are multicellular eukaryotes• Their cells lack cell walls• Their bodies are held together by
structural proteins such as collagen• Nervous tissue and muscle tissue are
unique to animals
![Page 5: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/5.jpg)
Reproduction and Development
• Most animals reproduce sexually, with the diploid stage usually dominating the life cycle
• After a sperm fertilizes an egg, the zygote undergoes cleavage, leading to formation of a blastula
• The blastula undergoes gastrulation, forming embryonic tissue layers and a gastrula
![Page 6: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/6.jpg)
LE 32-2_3
Zygote Eight-cell stage
Cleavage
Blastula Cross section
of blastula
Cleavage
Blastocoel
Blastocoel
Endoderm
Ectoderm
GastrulaBlastopore
Gastrulation
![Page 7: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/7.jpg)
• Many animals have at least one larval stage
• A larva is sexually immature and morphologically distinct from the adult; it eventually undergoes metamorphosis
![Page 8: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/8.jpg)
• All animals, and only animals, have Hox genes that regulate the development of body form
• Although the Hox family of genes has been highly conserved, it can produce a wide diversity of animal morphology
![Page 9: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/9.jpg)
The history of animals may span more than a billion years
• The animal kingdom includes not only great diversity of living species but also the even greater diversity of extinct ones
• The common ancestor of living animals may have lived 1.2 billion–800 million years ago
• This ancestor may have resembled modern choanoflagellates, protists that are the closest living relatives of animals
![Page 10: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/10.jpg)
LE 32-3
Stalk
Single cell
![Page 11: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/11.jpg)
Two distinct features that had to have preceded true
multicellularity.
1. The obvious feature is that cells must stick together;
specific adhesion molecules must be present that link cells
together, that aren't generically sticky and bind the organism
to everything. So we need molecules that link cell to cell.
2. A feature that distinguishes true multicellular animals from
colonial organisms is division of labor — cells within the
organism specialize and follow different functional roles. This
requires cell signaling, in which information beyond simple
stickiness is communicated to cells, and signal transduction
mechanisms which translate the signals into different patterns
of gene activity.
![Page 12: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/12.jpg)
http://7salemanimalkingdom.wikispaces.com/Sponges
Tube Sponge
![Page 13: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/13.jpg)
![Page 14: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/14.jpg)
LE 32-4
Hollow sphereof unspecializedcells (shown incross section)
Somatic cells
Colonial protist,and aggregate ofidentical cells
Gastrula-like“protoanimal”
Beginning of cellspecialization
Reproductive cells
Infolding
Digestivecavity
![Page 15: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/15.jpg)
Paleozoic Era (542–251 Million Years Ago)
• The Cambrian explosion marks the earliest fossil appearance of many major groups of living animals
• There are several hypotheses regarding the cause of the Cambrian explosion
![Page 16: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/16.jpg)
![Page 17: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/17.jpg)
http://www.astrobio.net/exclusive/2419/our-earliest-animal-ancestors
![Page 18: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/18.jpg)
![Page 19: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/19.jpg)
The Cambrian explosion or Cambrian radiation was
the relatively rapid appearance, over a period of many
million years, of most major Phyla around 530 million
years ago, as found in the fossil record. This was
accompanied by a major diversification of other
organisms, including animals, phytoplankton, and
calcimicrobes. Before about 580 million years ago,
most organisms were simple, composed of individual
cells occasionally organized into colonies. Over the
following 70 or 80 million years the rate of evolution
accelerated by an order of magnitude (as defined in
terms of the extinction and origination rate of species)
and the diversity of life began to resemble today’s.
![Page 20: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/20.jpg)
Charles Darwin considered this sudden
appearance of many animal groups with few or
no antecedents to be the greatest single
objection to his theory of evolution. He had even
devoted a substantial chapter of The Origin of
Species to solving this problem.
![Page 21: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/21.jpg)
Symmetry
• Animals can be categorized according to the symmetry of their bodies, or lack of it
![Page 22: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/22.jpg)
LE 32-7a
Radial symmetry
![Page 23: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/23.jpg)
Bilateral symmetry
Bilaterally symmetrical animals have:
A dorsal (top) side and a ventral (bottom) side
A right and left side
Anterior (head) and posterior (tail) ends
Cephalization, the development of a head
![Page 24: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/24.jpg)
Tissues• Animal body plans also vary according to the
organization of the animal’s tissues
• Tissues are collections of specialized cells isolated from other tissues by membranous layers
![Page 25: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/25.jpg)
• Animal embryos have concentric layers called germ layers that form tissues and organs
• Ectoderm is the germ layer covering the embryo’s surface
• Endoderm is the innermost germ layer
• Diploblastic animals have ectoderm and endoderm
• Triploblastic animals also have an intervening mesoderm layer
![Page 26: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/26.jpg)
Body Cavities
• In triploblastic animals, a body cavity may be present or absent
• A true body cavity is called a coelom and is derived from mesoderm
![Page 27: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/27.jpg)
A coelomate animal (mollusks, annelids, and all of
the more complex animals) is basically a set of
concentric tubes, with a gap between the gut and
the outer tubes.
(mollusks, annelids, and all of the more complex animals)
![Page 28: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/28.jpg)
LE 32-8a
Coelom
Coelomate
Body covering
(from ectoderm)
Digestive tract
(from endoderm)
Tissue layer
lining coelom
and suspending
internal organs
(from mesoderm)
![Page 29: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/29.jpg)
LE 32-8b
Body covering
(from ectoderm)
Digestive tract
(from endoderm)
Muscle layer
(from
mesoderm)
Pseudocoelom
Pseudocoelomate
A pseudocoelom is a body cavity derived from the
blastocoel, rather than from mesoderm
![Page 30: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/30.jpg)
LE 32-8c
Body covering
(from ectoderm)
Wall of digestive cavity
(from endoderm)
Acoelomate
Tissue-
filled region
(from
mesoderm)
Acoelomates are organisms without body
cavities
![Page 31: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/31.jpg)
Leading hypotheses agree on major features of the animal phylogenetic
tree
• Zoologists recognize about 35 animal phyla
• Current debate in animal systematics has led to the development of two phylogenetic hypotheses, but others exist as well
![Page 32: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/32.jpg)
• One hypothesis of animal phylogeny based mainly on morphological and developmental comparisons
![Page 33: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/33.jpg)
![Page 34: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/34.jpg)
The two major types of coelomates are protostomes and
deuterostomes. These groups differ in the characteristics of early
development.
![Page 35: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/35.jpg)
LE 32-10
Deuterostomia“Radiata”
Bilateria
Protostomia
Metazoa
Eumetazoa
Ancestral colonialflagellate
![Page 36: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/36.jpg)
• One hypothesis of animal phylogeny is based mainly on molecular data
![Page 37: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/37.jpg)
LE 32-11
Deuterostomia
“Radiata”
Bilateria
Lophotrochozoa
Metazoa
Eumetazoa
Ancestral colonialflagellate
Ecdysozoa
![Page 38: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/38.jpg)
Points of Agreement
• All animals share a common ancestor
• Sponges are basal animals
• Eumetazoa is a clade of animals with true tissues
• Most animal phyla belong to the clade Bilateria
• Vertebrates and some other phyla belong to the clade Deuterostomia
![Page 39: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/39.jpg)
Disagreement over the Bilaterians
• The morphology-based tree divides bilaterians into two clades: deuterostomes and protostomes
• In contrast, recent molecular studies assign two sister taxa to protostomes: the ecdysozoans and the lophotrochozoans
![Page 40: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/40.jpg)
http://www.brsd.org/education/components/scrapbook/default.php?sectiondetailid=4125&&PHPSES
SID=8907e11c0c2c592b81323e6a645eeff7
![Page 41: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/41.jpg)
http://www.utexas.edu/features/2008/tree/
![Page 42: The Evolution of Animal Diversity - geneseo.edusimon/bio105/class/guide1810.pdf · •Origin of the Animal Kingdom •Symmetry •Segmentation •Characteristics of Chordates….Vertebrates](https://reader035.fdocuments.in/reader035/viewer/2022062908/5ab9119c7f8b9ad13d8d43fc/html5/thumbnails/42.jpg)
The End