Chapter 27: Animal Diversity Flashcards
0
Q
Example of a good clade
A
Birds
-all birds descended from common ancestor that was a bird
1
Q
Grade
A
-level of morphological organization wherein a group of organisms share a number of characteristics but may not owe them to a common ancestor
2
Q
Clade
A
- Complete branch of an evolutionary tree
- All members descended from a single common ancestor that is a member of the group.
3
Q
Clade or Grade for Kingdom Animalia:
- All animals are heterotrophs
- heterotrophs obtain energy and organic molecules from other organisms, dead or alive
A
Grade
-many Protists are also ingestive heterotrophs
4
Q
Examples of a good grade
A
- “Cactus” growth form
- Flight
- Endothermy
- Multicellularity
- “Tree” growth form
- Vertebrate “leglessness”
5
Q
Clade or Grade for Kingdom Animalia:
-All animals are multicellular
A
Grade
-plants, fungi, protists, some prokaryotes have multicellularity
6
Q
Clade or Grade for Kingdom Animalia:
-Animals held together by:
•Unique Extracellular matrix of collagen, proteoglycan, adhesive glycoprotein (fibronectin), and integrin
•Unique intercellular junctions
A
Clade
7
Q
Clade or Grade for Kingdom Animalia:
-Animals typically show active movement
A
Grade
-many Protists and some prokaryotes are motile
8
Q
Clade or Grade for Kingdom Animalia:
-Animals are species-rich and diverse form
A
Grade
9
Q
Clade or Grade for Kingdom Animalia:
-Animals occupy all major habitats on earth
A
Grade
10
Q
Clade or Grade for Kingdom Animalia:
-Most animals reproduce sexually
A
Grade
11
Q
Clade or Grade for Kingdom Animalia:
-Most animals have a characteristic pattern of development.
Zygote->Cleavage->Blastula->Gastrula
-Unique Hox developmental genes
A
Clade
12
Q
Clade or Grade for Kingdom Animalia:
- Animals cells are organized into tissues
- Muscle tissue and nervous tissue are unique
A
Clade
13
Q
Synapomorphy characteristics for the Kingdom Animalia
A
• Unique Extracellular matrix of collagen, proteoglycan, adhesive glycoprotein (fibronectin), and integrin • Unique intercellular junctions • Development includes a blastula • Hox developmental genes • Muscle tissue and nervous tissue -sponges lack "true" tissues
14
Q
Phylum Cnidaria
A
- Jellyfish
- Anemones
- Corals
- ~10,000 species
15
Q
Phylum Porifera
A
• Sponges
• ~8000 species
- Phyla Calcarea and Silicea in text
17
Q
Phylum Acoela
A
- “acoel flatworms”
- formerly within Platyhelminthes
- appear to be basal bilaterians
- ~400 species
18
Q
Phylum Rotifera
A
- Rotifers or “wheel animals”
- Microscopic
- Mostly benthic and freshwater
- ~1800 species
19
Q
Phylum Platyhelminthes
A
- “flatworms” (planarians, flukes, tapeworms)
- formerly included acoelomorph worms
- ~20,000 species
20
Q
Phylum Mollusca
A
- Molluscs (snails, clams, octopuses, chitins, nudibranchs)
* ~100,000 living species
21
Q
Phylum Annelida
A
- Segmented worms
- Mostly marine but includes earthworms and leeches
- ~12,000 species
22
Q
Phylum Anthropoda
A
- Arthropods: millipedes, centipedes, spiders, scorpions, mites, ticks, crustaceans, insects
- > 1,000,000 species named, true number may be 30x
23
Q
Phylum Nematoda
A
- Roundworms
- Found pretty much everywhere, doing anything
- ~20,000 species named, true number may be 100x
24
Q
Phylum Echinodermata
A
- Echinoderms: sea stars, sea urchins, sand dollars, sea cucumbers, sea lilies
- Start out bilateral symmetrical but have radial symmetry as adults
- ~6,000 species
25
Phylum Chordata
- Subphylum Tunicata
• Urochordata: sea squirts and planktonic relatives
• ~2,200 species
- Subphylum Cephalochordata
• Lancelets or amphioxus; fish-like, marine, burrowers
• ~30 species
- Subphylum Craniata
• Vertebrates: lampreys, fish, amphibians, reptiles, birds, and mammals
• Hagfishes
• ~54,000 species
26
How old are animals?
• Oldest unambiguous fossil animals:
- ~550 million years ago
• Molecular estimate:
- older, maybe 700 million to 1 billion years
• Compare with
- Age of Earth: 4.6 billion years
- 1st Prokaryotes: 3.5-3.9 billion years ago
- 1st Eukaryotes: 2.1 billion years ago
27
Cambrian Explosion
* Relatively brief time in geologic history when many present-day phyla of animals first appeared in the fossil record
* This burst of evolutionary change occurred about 535-525 million years ago and saw emergence of first large, hard-bodied animals
28
Four keys of the animal body plan
* Evolution of tissues
* Evolution of bilateral symmetry
* Evolution of a body cavity
* Evolution of deuterostome development
29
Evolution of tissues
• Tissue is group of similar cells organized into a structural and functional unit (and isolated from other tissues by a membranous layer)
• Sponges lack "true" tissues
- May have epidermis (pinacoderm)
- Closer to unicellular level of organization
• Cell types remain totipotent (ability to differentiate into other cell types)
- Sometimes called "Parazoa"
• Other animals have well-developed tissues ("Eumetazoa")
30
Evolution of bilateral symmetry
• Asymmetry
- Lacking definite symmetry
- Characteristic of many sponges
• Radial symmetry
- Symmetry about a radius or diameter (starfish)
- Characteristic of Cnidaria and adult echinoderms
• Bilateral symmetry
- Right and left halves that are mirror images (humans)
- Have top and bottom (dorsal & ventral), front and back (anterior & posterior), and left and right
- "Bilateria"
31
Bilateria
• 3 germ layers
- Basic tissue layers in early embryo which develop into organs and tissues
- Endoderm, mesoderm, & ectoderm
- "Triploblastic"
- Radiata (Cnidaria & Ctenophora) are diploblastic
- Sponges have only 1 "germ layer"
• Cephalization
- Evolution of definite head and brain area
- Associated with greater levels of activity and greater coordination of that activity
- Sense organs and brain are located at anterior end
32
Evolution of a body cavity (coelom)
• Coelom
- fluid- or air-filled space between digestive tract and outer body wall
• Advantages
- Gut can be longer, and can move independently of body wall (e.g., peristalsis)
- Allows space into which structures can expand (e.g., eggs in ovary)
- Provides a simple circulatory system, if fluid filled
- Provides a storage space for waste products, from which they me be discharged to outside via excretory ducts
- Provides a hydrostatic organ, if fluid filled
33
Types of body cavities
• Acoelomate
- No body cavity
• Blastocoelomate("Pseudocoelomate")
- Cavity is between mesoderm and endoderm (e.g., Nematoda and Rotifera)
- Old name bad: not "false", just different
• Coelomate
- Cavity is fully enclosed within mesoderm (e.g., mollusks, arthropods, echinoderms, & chordates)
- Reduced in some and placed with "hemocoel or haemocel"
• Cavity is expansion of circulatory system
34
Acoelomate
- No body cavity
- Space between the gut and the body wall is filled with a more or less solid mass of mesodermal tissue
- E.g., Platyhelminthes, Acoela
35
Blastocoelemate
- Fluid-filled cavity between the gut and the mesoderm of the body
- Developmental remnant of bastocoel
- E.g., Nematoda & Rotifera, others
36
Coelomate (Eucoelomate)
- Fluid-filled cavity fully enclosed by mesoderm
- Characteristic of "higher" Bilateria
- E.g., Annelids, Molluscs, Arthropods..
37
Protostome-Deuterostome differences
* Cleavage
* Source of mesoderm & formation of coelom
* Fate of blastopore
* Fate of embryonic cells
38
Protostome or Deuterostome:
| - Spiral Cleavage
Protostome
39
Protostome or Deuterostome:
| - Radial Cleavage
Deuterostome
40
Protostome or Deuterostome:
- Mesoderm comes from lip of blastopore
- Coelom forms as split within mesoderm (schizocoely)
Protostome
41
Protostome or Deuterostome:
- Mesoderm comes from an "out pocketing" of the wall of the early guy (archenteron)
- Coelom forms as the pocket "pinches off" (enterocoely)
Deuterostome
42
Protostome or Deuterostome:
| - Blastopore develops into the mouth
Protostomes ( "first" & "mouth")
43
Protostome or Deuterostome:
| - Blastopore develops into the anus
Deuterostomes ( "second" & "mouth")
44
Protostome or Deuterostome:
- Determinate (mosaic) development
- Blastomeres lose totipotency with first cleavage division
Protostomes
45
Protostome or Deuterostome:
- Indeterminate (regulative) development
- First few cleavage divisions yield totipotent daughter cells ( e.g.,monozygotic twins, triplets, ...)
Deuterostomes
46
"Old" view of animal phylogeny
Based on morphology and embryology
47
"New" view of animal phylogeny
Based on genetic sequence data
48
Similarities or difference between "old" & "new" views of animal phylogeny:
• Animals are a natural group
- monophyletic, a clade
Similarity
49
Similarities or difference between "old" & "new" views of animal phylogeny:
• Sponges are basal animal
Similarity
50
Similarities or difference between "old" & "new" views of animal phylogeny:
• There is a large clade, Eumetazoa
- have true tissues
- all but sponges & few others
- basal Eumetazoa typically diploblastic, with radial symmetry
Similarity
51
Similarities or difference between "old" & "new" views of animal phylogeny:
• Most animal belong to clade Bilateria
- triploblastic & bilaterally symmetry
- "Cambrian explosion" was explosion of this clade
Similarity
52
Similarities or difference between "old" & "new" views of animal phylogeny:
• Deuterostomia is a clade
- including Chordates & Echinoderms
Similarity
53
Similarities or difference between "old" & "new" views of animal phylogeny:
• "Protostimes" consist of two major clades:
- Ecdysozoa
- Lophotrochozoa
Difference - old view
54
Look at pictures and diagrams throughout the slides
Review last few slides
55
Strong support for hypothesis that animals are derived from _______
Choanoflagellates
56
The most diverse Phyla is _______
Arthropoda
57
Ecdysozoa
```
• Consists of Phyla:
- Nematoda
- Arthropoda
• Characterized by:
- SHEDDING
- Bilateral symmetry
- Triploblastic
```
58
Lophotrochozoa
```
Consists of Phyla:
- Platyhelminthes
- Rotifera
- Mollusca
- Annelida
Characterized by:
- Early lophophore feeding OR trochophore larva stage
- Bilateral symmetry
- Triploblastic
```
59
Platyhelminthes and Acoela are _________ (acoelomate/blastocoleomate/eucoelomate)
Acoelomate
60
Nematoda and Rotifers are _________ (acoelomate/blastocoleomate/eucoelomate)
Blastocoleomate
61
Review the slides on Clades, Grades, & Taxa
Good luck
62
Porifera (sponges) are ______ (asymmetric/radial symmetric/bilaterial symmetric)
Asymmetric
63
Cnidaria (jellyfish, hydra) are ______ (asymmetric/radial symmetric/bilaterial symmetric)
Radial symmetric
64
A clade is a __________ (synapomophy/symplesiomorphy)
Synapomophy
65
Monophyletic taxon
– A set of species that includes the most recent common ancestor of the set, and all of the species descended from that common ancestor.
– A complete branch of an evolutionary tree (a clade).
– E.g., mammals
66
Paraphyletic taxon
– A set of species that includes the most recent common ancestor of the set, and some but not all of the species descended from that common ancestor.
– An incomplete branch of an evolutionary tree
– Examples on slides
67
Polyphyletic taxon
– A set of species that does not includes the most recent
common ancestor of the set.
– Parts of two different branches of an evolutionary tree.
68
A set of species that includes the most recent common ancestor of the set, and SOME BUT NOT ALL of the species descended from that common ancestor?
Paraphyletic taxon
69
A set of species that includes the most recent common ancestor of the set, and ALL of the species descended from that common ancestor?
Monophyletic taxon
70
A set of species that does not include the most recent
| common ancestor of the set?
Polyphyletic taxon
71
True or False: Monophyletic taxon are an incomplete branch of an evolutionary tree (a clade)
False, Monophyletic taxon are an COMPLETE branch of an evolutionary tree (a clade)
72
True or False: Polyphyletic taxon are an incomplete branch of an evolutionary tree
False, Paraphyletic taxon are an incomplete branch of an evolutionary tree
73
Flipperoidea is an example of a ______ taxon
Polyphyletic taxon
74
Synapomorphy
- Shared, DERIVED character similarity
| - Help identify monophyletic taxa (clades)
75
Symplesiomorphy
- Shared, ANCESTRAL similarity
| - Likely lead to paraphyletic taxa
76
Echinoderms have __________ symmetry in their adult life.
Radial
