1
Q
Invertebrates
A
animals lacking a backbone
- 95% of known animal species
- occupy almost every habitat on earth
- morphologically diverse
2
Q
Porifera
A
sponges
- sedentary
- live in marine or fresh waters
3
Q
Lophotrochozoa
A
- platyhelminthes
- rotifera
- acanthecephala
- nemertea
- cycliophora
- ectoproctaBrachiopoda
- annelida
- mullosca
4
Q
Ecdysozoa
A
- Loricifera
- Priapula
- Tardigrade
- Onychophora
- Nematoda
- Arthropoda
5
Q
Deuterostomia
A
- Hemichordata
- Chordata
- Echinodermata
6
Q
Cnidarians are an…
A
ancient phylum of eumetazoans
-one of the oldest in eumetazoan clade
7
Q
Cnidaria
A
both sessile and motile forms
-jellies, corals and hydras
8
Q
Cnidaria body plan
A
simple, diploblastic+radial body plan:
-sac with central digestive compartment (gastrovascular cavity)
9
Q
Gastrovascular cavity
A
sac with central digestive compartment observed in cnidarians
10
Q
Bilateria body plan
A
Have bilateral symmetry and triploblastic development. Most have choelom and digestive track with two openings:
- Lophotrochozoa
- Ecdysozoa
- Deuterostomia
11
Q
Lophotrochozoa
A
- some develop lophophore for feeding
- others pass through a trochophore larval stage
- others have neither feature
- flatworms
- rotifers
- ectroprocts
- brachiopods
- molluscs
- annelids
12
Q
Rotifers
A
- tiny
- inhibit fresh water, ocean water or damp soil
- similar to many protists, but are multicellular (truly) and have specialized organ systems
13
Q
Why are Echdysozoans are the most species rich animal group?
A
- covered by a tough coat (cuticle)
- Cuticle is shed/molted (ecdysis)
14
Q
two largest echdysozoan phyla
A
- Nematodes
2. Arthropods
15
Q
Nematodes
A
- roundworms
- include many parasites and C. Elegans
- found in: most aquatic habitats, in soil, moist tissue of plants, in body fluids, tissues of animals
16
Q
Arthropods
A
2/3 of known species of animals
17
Q
Phyl: Echinoderms
A
-sea stars, sea urchins
18
Q
Phyl: Chordates
A
- Bilaterally symmetrical choelomates with segmented bodies
- did NOT evolve from echinoderms; but have evolved separately for at least 500million years
- 2 subphyla:
1. invertebrates
2. vertebrates
19
Q
Clade Deuterostomia comprised of… (2)
A
- Echinoderms
2. Chordates
20
Q
Deuterostomes share developmental characteristics…
A
- Radial cleavage
- Formation of the anus from the blastopore
* defined primarily by DNA similarities*
21
Q
Chordates have a…
A
-Notochord+dorsal, hollow nerve cord
22
Q
Vertebrates have a…
A
-Backbone
23
Q
Gnathostomes
A
-vertebrates that have jaws
24
Q
Tetrapods
A
-gnathostomes that have limbs
25
Amniotes
-tetrapods that have a terrestrially adapted egg
26
Mammals are...
Amniotes that have hair and produce milk
27
Humans are...
Mammals that have a large brain and bipedal locomotion
28
365million years ago
one lineage of vertebrates colonized land
29
how many vertebrates (species)
52 000;
- including the largest organisms ever to live on earth.
- great disparity, wide range of differences within the group.
30
Chordates
Phylum chordata
- bilaterian
- deuterostomia
- comprises all vertebrates and two groups of invertebrates
31
derived characters of chordates (4)
- all share set of derived characters; some species have some of these trains only during embryonic development
1. Notochord
2. Dorsal, hollow nerve cord
3. Pharyngeal slits/clefts
4. Muscular, post-anal tail
32
Notochord
a longitudinal, flexible rod b/w digestive tube and nerve cord.
- provides skeletal support throughout most length of chordate
- in most vertebrates, a more complex+jointed skeleton develops; the adult retains only remnants of embryonic notochord
33
Dorsal, hollow nerve cord
- develops from a plate of ectoderm, rolls into tube (dorsal to notochord)
- develops into CNS
34
pharyngeal clefts
in most chordates, grooves in pharynx that develop into slits that can open to the outside of the body
35
pharyngeal slits (functions)
1. Suspension-feeding structures in many invertebrate chordates
2. Gas exchange in vertebrates (except vertebrates with limbs and tetrapods).
3. Develop into parts of the ear, head, neck (in tetrapods).
36
Muscular, post-anal tail
Chordates have tail posterior to anus
- in many species, tail greatly reduced during embryonic development
- contains skeletal elements and muscles
- provides propelling force (in many aquatic species)
37
Tunicates
- most resemble chordates as larvae
| - adults draw in water to filter food particles
38
Vertebrates have... and tunicates have...
Two or more sets of Hox genes
only one cluster of Hox genes
39
Vertebrates have (2) derived characters
1. Vertebrae enclosing a spinal cord
| 2. An elaborate skull
40
Earliest vertebrates...
lacked jaws; two lineages remain today:
- Hagfishes
- Lampreys
41
Gnathostomes are...
Vertebrates that have jaws
- outnumbers jawless vertebrates
- sharks, et al
- ray-finned fishes
- Lobe-finned fishes
- Amphibians
- Reptiles (including birds)
- Mammals
42
Gnathostomes hypothesized
to have evolved from skeletal supports of the pharyngeal (gill) slits
43
Chondrichthyans
vertebrates that have a skeleton composed primarily of cartilage
subclass 1
-sharks
-Rays, et al
subclass 2
-ratfishes
chimaeras
44
Osteichthyes
the vast majority of vertebrates belong to this clade of gnathostomes:
- nearly all have bony endoskeleton
- include bony fish tetrapods
- aquatic Osteichthyes=fish!
45
Tetrapods
are Gnathostomes that have limbs:
- four limbs, with feet & digits
- neck, allowing separate movement of head
- fusion of pelvic girdle to backbone
- absence of gills (excl. some aquatic species)
- ears for detecting airborne sounds
46
One of the most significant events in vertebrate evolutionary history...
when fins of some lobe-fins evolved into the limbs & feet of tetrapods
47
(class) Amphibia
approx 6, 150 species:
- frogs
- toads
- salamanders
- Caecillians
48
Amniotes are...
Tetrapods that have a terrestrially adapted egg
49
Amniotic egg was the key...
adaptation to life on land
50
amniotic eggs of most reptiles (& some mammals)
have a shell
51
Other terrestrial adaptations of Amniotes...
- relatively impermeable skin
| - ability to use the rib cage (to ventilate lungs)
52
Reptile (clade)
```
Have scales (waterproof barrier), most lay shelled eggs on land.
Most are ectothermic, except birds (endothermic)
```
- tuataras
- lizards
- snakes
- turtles
- crocodilians
- Birds
* some extinct groups*
53
endothermic
capable of maintaining body temperature through metabolism
54
ectothermic
absorbing external heat as the main source of body heat
55
Birds
Dinosaurs (hence reptile clade), but almost every feature of their reptilian anatomy has been modified to adapt for flight:
-wings with keratin feathers
56
Derived characteristics of birds (4)
1. Lack of urinary bladder
2. Females with only one ovary
3. Small gonads in both sexes
4. Loss of teeth
57
Derived characteristics of mammals (5)
1. Mammary glands (produce milk)
2. Hair
3. High metabolic rate (due to endothermy)
4. Larger brain than other vertebrates (of equal size)
5. Differentiated teeth
58
Early mammalian evolution
(by early Cretaceous) three lineages of mammals emerged:
1. Monotremes
2. Marsupials
3. Eutherians
* mammals did not undergo a significant adaptive radiation until after Cretaceous*
59
Monotremes
egg-laying mammals
- Echidnas
- platypus
60
Marsupials
mammals whom embryo develops within uterus and born very early in gestation:
-opossum
61
Primates (mammalian order)
have hands and feet adapted for grasping, and flat nails.
- lemurs
- tarsiers
- monkeys
- apes (humans part of this group)
62
Primate derived characteristics (4)
1. Large brain, short jaws
2. Fwd-looking eyes, close together on face (provides depth perception)
3. complex social behaviour & parental care
4. Fully opposable thumb (monkeys & apes)
63
200 000 years ago
species homo sapien's age
64
Derived characteristics of humans (compared to others in ape group)
1. Upright posture and bipedal locomotion
2. Larger brains, capable of; language + symbolic thought, artistic expression, the manufacture and use of complex tools
3. Reduced jawbones + jaw muscles
4. Shorter digestive tract
65
99% identical genomes
humans and chimpanzees; changes in regulatory genes can have large effects.
66
Paleoanthropology
the study of human origins
67
Hominins
are more closely related to humans than to chimpanzees
| *extinct*
Biol225
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