Chapter 16: Evolution of Animals Flashcards
proper reasons for the Cambrian explosion?
complex predator-prey relationships
Another hypothesis focuses on the evolution of genes
four key points in animal evolution?
1) Multicellularity (true tissue) :: sponge vs other (have true tissue)
2) Bilateral symmetry (radial or bilateral symmetry)
3) Body cavities
4) True coelom (coelom from cell mass, coelom from digestive tube)
difference between a pseudocoelom and a true coelom?
Pseudocoelom’s body cavity is not completely lined with the peritoneum(tissue) derived by mesoderm, middle layer
True coelom’s is completely lined by tissue derived from mesoderm
structural of Porifera Phylum
- Sponges
- Sessile animals, the simplest animals, range in height from about 1cm to 2 meters.
- Sponges have no nerves or muscles, but the individual cells can sense and react to changes in the environment
- Lack real tissues and have amoebocyte (skeleton)
structural of Cnidarian Phylum?
- Radial symmetry and having tentacles with stinging cells.
* Jellies, sea anemones, hydras and coral animals
structural features and representatives of Platyhelminthes Phylum?
• Simplest bilateral animals, leaflike or ribbonlike, 1 mm to 20 meters in length.
• Planarians are nonparasitic flatworms
-tapeworms, flukes
structural features and representatives of Nematoda Phylum?
- Cylindrical bodies
- Have complete digestive tract
- Body cavity (pseudocoelom)
the structural features of Mollusca Phylum?
- Soft-bodied animals, mostly protected by a hard shell
- 3 part body plan: a muscular foot, visceral mass, and mantle-fold of tissue (wraps the visceral mass & secretes the shell)
three classes and representatives of Mollusca Phylum?
gastropod (snail and slugs)
bivalves (clams and oysters)
and cephalopod (squids and octopuses),
structural features of Annelida Phylum?
- The body is divided into a series of repeated parts (body segmentation)The coelom is partitioned by walls. It has segmental blood vessels.
- Less than 1 mm to 3 m in length
the three classes and representatives of Annelida Phylum?
earthworms, polychaetes, leeches
structural features of Arthropods Phylum?
- Segmented animals, with variety of function ex walk feed sense recep
- Has exoskeleton — constructed from layers of protein and chitin (a polysaccharide)
- Undergo molting (shed old exoskeleton, secrete larger one)
four classes and representatives of Arthropods Phylum?
- Arachnids (scorpion, spiders, ticks, mites) – 4 pairs legs & feeding appendages
- Crustaceans (crabs, lobsters, crayfish, shrimps)
- Millipedes (eat decay plant matter) and centipedes (terrestrial carnivores)
- Insects
structural features and representatives of Echinoderms Phylum?
Spiny surface, sessile-moving, lack body segment; Have an endoskeleton beneath the skin; have water vascular system,
Sea star,sea urchin
common four key features of Chordata Phylum?
①, hollow nerve cord
②notochord, a flexible, longitudinal rod, located between the digestive tract and the nerve cord
③pharyngeal slits
④post-anal tail, a tail to the rear of the anus
Besides vertebrate, what are the other two subphyla and representatives of Chordata Phylum?
Tunicates and Lancelets
What is the earliest vertebrate? When did it appear the first time on earth? What are its special structural features?
Agnathans, evolved during early Cambrian period, about 540 million years ago
Lacked jaws, paratistes use jawless mouth as suckers to attach large fishes and draw blood
A shark belongs to Cartilaginous fishes or Bony fishes?
• Cartilaginous fishes
What kind of fish has the closest genetic relationship with amphibian?
• Lobe-finned fishes
special adaptations of Reptiles to terrestrial environment?
- Keratin containing scales
- Waterproof skin & prevent dehydration in dry air
- Evolved amniotic eggs
structural features of Birds?
- Bones have a honeycombed structure that makes them strong but light; they no internal organs; they are endotherms
- wings adapted for soaring on air currents (feathers made of keratin)
When did mammals firstly appear on land?
225 million years ago,
What are the two features of mammals?
Hair and mammary glands
Which three major groups are mammals divided into? What are the structural features and representative respectively of these three groups?
A. Monotremes- platypus, echidnas
B. Marsupials- kangaroos and koalas (pouched animals)
C. Eutherians- monkey, apes, humans (placental animals)
When did primates originate?
65 million years ago
What are the structural features of primates?
- were small, arboreal mammals
- have limber shoulder joints
- dexterous hands
- eyes of primates are close together on the front of the face
What two main groups are primates classified into? And what are the representatives of these two groups?
1) Prosimians – lemurs, lorises, pottos, tarsiers
2) Anthropoids- monkey, apes, humans
How long is the history of human and chimpanzee?
5-7 million years ago, human and ages diverged
What is earliest bipedal walking Hominidae? And when did it firstly appear?
afarensis, 4 million years ago
When did all species of Australopithecus extinct?
.4 million years ago
When did Homo habilis appear firstly?
2.5 million years ago
What structural traits does Homo habilis have?
Enlarged brains, brain cavity, made handmade stone tools
When did Homo erectus start global dispersal?
1.8 million years ago
When compared with Homo habilis, what special evolutional features does Homo erectus have?
A. taller than Homo habilis and had a larger brain capacity
B. resided in huts or caves, built fires
C. made clothes from animal skins, and designed stone tools that were more refined than the tools of Homo habilis
Development of animals
Zygote→ Blastula→ Gastrula→ Larva→ Adult
What structural differences are between Neanderthals and homo sapiens?
Neanderthals had slightly heavier browridges and less pronounced chins, but their brains were slightly larger than humans.
What are the two hypotheses on the origination of homo sapiens?
A. Multiregional model- modern humans evolved simultaneously in different part of the world.
B. Monogenesis Model- human arose from a single archaic group in Africa. (based on molecular DNA in mitrochondria)
What are the three stages of cultural evolution?
A. Nomads (2 million years ago) made tools, organized communal activities and divided labor, produced beautiful ancient art.
B. Development of agriculture in Africa and Eurasia about 10,000 to 15,000 years ago. People settled permanent and formed cities.
C. Industrial Revolution, which began in the eighteenth century. Since then, new technology has escalated exponentially, people formed high-tech society.
Concept: metamorphosis
the process of transformation from an immature form to an adult form which two form are totally different
