Cambarian explosion
535-525 MYA -All phyla formed -New predator-prey relationships -Adaptive Radiation & Diversification
Animals- Muscles, nerves, tissues, absorptive nutrition by ingestion
Cephalization
the concentration of nerve tissue and sensory organs at the anterior end of an organism
origin of mammals
about 200 million years ago
The last common ancestor of all animals was probably a
flagellated protist
metamorphosis
change of form during embryonic development
Clade Ecdysozoa
Phylum Nematoda Phylum Arthropoda
Clade Lophotrochozoa
share the presence of a trochophore larva or a feeding structure called a lophophore -Platyhelminthes, Rotifera, Mollusca, Annelida
Clade Eumetazoa
animals with true tissues
Clade Parazoa
Phylum Porifera -> Sponges
Clade Radiata
Phylum Cnidaria and Phylum Ctenophora -Radial Symmetry
Clade Bilateria
contains Lophotrochozoa, Ecdysozoa, and Deuterostomia -Bilaterally symmetrical
Clade Deuterostomia
echinoderms and chordates -Triploblastic
Deuterostomes
Animals in which the blastopore becomes the anus during early embryonic development
Protostome
an animal whose mouth is formed from the blastopore -Determinate And Spiral cleavage
protostomates
mouth forms from blastopore. Determinate Cleavage -Phylum Annelidia -Phylum Mollusca -Phylum Platyhelminthes -Phylum Arthropoda
Blastula
The hollow ball of cells marking the end stage of cleavage during early embryonic development
blastopore
The opening of the archenteron in the gastrula that develops into the mouth in protostomes and the anus in deuterostomes
Chordate Features
Dorsal, hollow nerve cord Notochord Pharyngeal slits Muscular Postanal tail Segmented Muscles
Deuterostomate, bilateral, triploblastic
Cleavage (embryology)
-series of rapid mitotic divisions in early embryonic development -increasing ratio of nuclear to cytoplasmic material -increases surface-to-volume ratio of each cell, improving gas and nutrient exchange
-Deutro vs proto
Gastrulation
In animal development, a series of cell and tissue movements in which the blastula-stage embryo folds inward, producing a three-layered embryo, the gastrula.
-Can tell Triplo vs Diplo
Subphylum Cephalochordata
lancelets (amphioxus)-oldest chordates -Suspension feeders -Pharyngeal slits for water to go in/exit -cilia on outside -Diatoms and dinoflagellates inside
**Features in adults AND larvae
Ecdysis
periodic shedding of the cuticle in arthropods or the outer skin in reptiles
Subphylum Urochordata
tunicates -> Chordate features ONLY in larvae -Adults are IMMOBILE and lose chordate features (Derived traits -> ancestors=chordates) -Only have pharyngeal slits
Unikonta
amoebozoans and opisthokonts
Subphylum Vertebrata
Vertebrates; cephalized chordates a. A vertebral column b. Closed circulatory system c. Neural crest -> Infolded ectoderm d. Bones e. Brain f. Cranium (skull)
**2 sets of hox genes
Opisthokonta
the eukaryotic supergroup that contains the fungi, animals, and choanoflagellates
Subphylum Cyclostomata (Circle Mouth)
Class Mixini and Petromyzontida -Jawless -Simple Vertebrates
Clade Metazoa
all animals
Class Mixini
hagfish (Not fish) -Jawless Craniates -Marine scavengers -skull, simple vertebra -Cartilaginous-> NO COLLAGEN -Make slime for protection
Class Petromyzontida
Lampreys -Cartilaginous-> NO COLLAGEN -Jawless, vertebra-like extensions on notochord -Parasites; eat blood -> larvae suspension feed
Subphylum Gnathostomes (Jaw Mouth)
-JAWS -> Predators -Additional hox gene cluster -Mineralized endoskeleton -Lateral line system -> better senses and bigger brain -Tetrapods -> legs and arms
**Fish, amphibians, reptiles, mammals
Origin of Jaws
-Skeletal rods supporting pharyngeal slits fuse around the mouth -Other slits become GILLS for respiration -No more suspension feeding
Chondrichthyes (cartilaginous fish)
Sharks And Ray fish & ratfish -true jaws and Cartilage endoskeleton -paired fins -hypertonic to Ocean -Must be constantly swimming
Superclass Osteichthyes (bony fish)
-Endoskeleton made entirely of hard calcified bone -Operculum= protects gills and allows fish to draw in H2O and breathe -swim bladders= "Lungs" -> controls buoyancy -gills for respiration -Lateral line system -Oviparous
3 Classes: Class Actinopterygii Class Actinistia Class Dipnoi
Class Actinopterygii (ray-finned fishes)
-Origin Silurian Period 444-419 MYA -Aquatic -Fins supported by long flexible rays -> maneuvering, self defense
Class Actinistia (lobe-finned fish)
-Rod shaped bones surrounded by thick layer of muscle in pelvic and pectoral fins -3rd surviving group of lobe fins= survived on land -Silurian Period
Class Dipnoi (lungfish)
-Gills= main organs for gas exchange
Class Amphibia
Paleozoic- 365 MYA -Flattened head and arms come to sides -Presence of neck -Shell-less eggs -Frog= soft skin -Toad= rough skin
**Gave rise to reptiles and mammals
3 clades: Urodela- Salamanders Anura- Frogs (tail-less) Caecilians (Apoda)- (snakes Legless)
Missing Link Traits-Amphibians
Juveniles- Gills. Swim tail, Webbed feet, fish like Adults- Lungs, moist skin, H2O to reproduce
Reptile characteristics
Water proof scales Independent from water -DRY skin, keratinized cells -Lay Amniotic eggs on land -> Pre-fertilized= SHELLS COVER ZYGOTE -Egg Shell: Stores H2O, leathery, waste excretion (NH3-> Uric acid), gas exchange (Air pockets)
Reptile groups
Synapsids -Therapsids-> give rise to mammals -1 opening in temporal arch
Diapsids -Dinosaurs, crocodiles, snakes, lizards, birds -2 openings in temporal arch
Anapsid -Turtles -NO opening in temporal arch
Types of teeth in mammals
incisors= shredding canines= ripping and piercing molars= grinding
mammal characteristics
-Warm blooded -High metabolism -Sweat glands to cool -specialized teeth -hair -Mammary glands -Extended care of young -Learned behavior
Subclass Prototheria
monotremes (Porcupines) -Warm blooded -Lay eggs -> Young hatch and live outside mom -hair -NO NIPPLES -Milk glands
Subclass Metatheria (marsupials)
-Live Birth -Temporary placenta -Underdeveloped young -> stay in mom's pouch -Attached to nipple -> feed off nipple for milk
Subclass Eutheria (placental mammals)
-Live birth -Fully developed child after birth -Young held inside past egg feed development -Feed by umbilical cord attached to placenta -Long-term placenta -Feed off breast for milk-> NOT physically attached to nipple
**Convergent evolution with Marsupials -> look similar
Tetrapods
vertebrate animals having four feet, legs or leglike appendages -digits on feet and arms -Neck= sep movement of head -Fusion of pelvic girdle and backbone -Ears-> detect airborne sounds -Absence of gills
Origins of flight
Arose 4 times
Pterosaurs -> Flying reptiles
Bats
Birds
Insects
2 theories: Tree Down Theory Ground Up Theory
Bird (aves) characteristics
-feathers -> Flight -forelimbs have become wings -lay eggs with hard shells -4 chambers in heart -Warm blooded high metabolism -Lungs and air sacs= one way flow -Hollow bones -Parental care and social behavior -One ovary -NO TEETH OR URINARY BLADDER
Primates New Features
-Origins to 65 MYA -Insect eating nocturnal mammals -Derived Trait-> Life in trees -grasping hands and feet -Fully opposable separate big thumb -Fingerprints -Larger brain -Short jaws -Hand to eye coordination -Flat nails, no claws -Long parental care -Learned Behavior -Single births ANY time of yr
Primate Groups
prosimians -Lemurs and Tarsiers -> more related to OG primates
anthropoids -Monkeys and Hominoids -> Split from Prosimians 45 MYA
New World Monkeys
All species are arboreal -Nostrils open to the side -Many have prehensile tails. -Squirrel and Capuchin monkeys
Old World Monkeys
Split from New World Monkeys 35 MYA Include arboreal and terrestrial species -Lack prehensile tails -Nostrils open downward -Rhesus Monkeys, baboons, macaques
Hominoids
apes and humans Split from Monkeys 20-25 MYA -More flexible/learned behaviors -NO PREHENSILE TAILS -Larger brain to body ratio / larger size -Social Behavior
Orangutans and Gibbons -> Primarily Arboreal Gorillas, Chimps, Us -> Primarily Terrestrial
Hominins
-Humans and our direct ancestors since split from Chimps 6-8 MYA
Major Groups: Australopithecus Paranthropus Homos -> some co-existed
Hominin Evolution/Characteristics
Driven by Life on LAND -bipedalism -Smaller Jaw with SPECIALIZED teeth -> Omnivorous diet -Pronounced chin -Less Sexual Dimorphism -> no real harem/dominant male -Tool use -Language -Social behavior -Walking Upright -expanded brain -Decreased sense in smell nut increased vision and muscle coordination -Eyes are larger and directed forward -Mosaic Evolution-> Not all traits happened at same time
mosaic evolution
a phenotypic pattern that shows how different traits of an organism, responding to different selection pressures, may evolve at different rates
Chromosome anomaly
Other extant Hominids -> 2n=48 -2 Ape chromosomes fuse -> become humans with 2n=46
Paedogenesis
The early development of sexual maturity in an adolescent -> Larger cerebrum in hominins
Sahelanthropus tchadensis
The earliest pre-australopithecine species found in central Africa -OLDEST-> 6-7 MYA (discovered 2002)
-Reduced Canine teeth -Flatter Faces -More Upright & Bipedal other hominids
Orrorin tugenensis
-6.1 MYA-5.8 MYA (Discovered 2000) -Evergreen forest -> Not in open grassland -Oldest Bipedal Fossil Evidence
Ardipithecus ramidus
4.4 MYA -"Ardi"-> most complete skeleton found -wooded environment-> contradicts open Savannah theory for origins of bipedalism -small brain -walked upright -big toe separated from other toes
Australopithecus
the earliest humanlike creature 3-4 MYA -Fully upright walking -Human-like teeth and hands
1/3 of modern human skull size -Lasted over 1 MY in South and East Africa
Homo Naled
2.5-3 MYA (Not sure) (found 2012) -Base of Homo Genus -Fully Bipedal -Fine Hand/Motor skills
Homo Habilis
1.6-2.5 MYA -Walked upright for 2 MY -USED Brains -Fashioned STONE TOOLS -Co-existed with Australopithecus for 1 MY
Homo ergaster
1.6-1.9 MYA -Less sexual dimorphism and more monogamy -larger brains -Slender legs -> Long distance walking -> Migrations -Smaller teeth= Prepared/cooked food -Smaller fingers= no more climbing trees -More advanced tools and more habitats
Intermediate btwn Habilis and Erectus
Homo erectus
300,000 YA- 1.8 MYA First to Migrate OUT to Europe and Asia -Larger populations -More advanced hunting -> Oldest evidence of use of fire -Java Man and Pecking Man
Homo heidelbergensis
A transitional species between Homo erectus and Homo sapiens -Descended from H. ergaster in Africa and spread out
Europe in ICE AGE: 3 populations LOSE CONTACT and speciate:
Europe: Neanderthals Asia: Denisovans Africa: Homo Sapiens (us)
Homo neanderthalensis
40,000-200,000 YA -Buried dead -Hunting tools from stone and wood -Carnivorous -Larger brain size than us (Maybe)
**Interbred With H. sapiens -> 20% European genome is Neanderthal (Except Y chromosome 100% Sapien)
Denisovans
41,000 YA -Formed from H. heidelbergensis -More closely related to Neanderthals than us -Not much info -> only have small DNA fragments -Fossils in Spain -> May have interbred with Neanderthals
**Papua New Guinea ppl have Denisovan DNA -May have been around until 60,000-110,000 YA
Ethology
The scientific study of how animals behave, particularly in natural environments.
behavior
what and how animals do things
Reductionism
Single out/isolate variable you are testing
causes of behavior
Ultimate Causation: Ecological/Evolutionary reason -> How to maximize fitness
Proximate Causation: Trigger/signal causes behavior
Innate Behavior
Genetically determined behavior -> Instinct
fixed action pattern
A sequence of unlearned acts that is essentially unchangeable and, once initiated, usually carried to completion.
-Perform behaviors without having seen them performed -> Don't think abt it, instinctive -Triggered by sign/stimulus
learned behavior
a behavior that has been learned/modified from experience or observation
Learning
The modification of behavior based on specific experiences.
Maturation
biological growth processes that enable orderly changes in behavior, relatively uninfluenced by experience -Period of learning
Habituation
A loss of responsiveness to stimuli that convey little or no information. -Temporary-> can be reversed
Imprinting
the process by which certain animals form attachments during a critical period very early in life -PERMANENT
classical conditioning
a type of learning in which one learns to link two or more stimuli and anticipate events -Link background stimulus with reward or harm
operant conditioning
Learning based on the consequences of responding -Trial and Error learning -Can either reinforce or diminish behavior based on reward or harm
Cognition
all the mental activities associated with thinking, knowing, remembering, and communicating
-Can make judgement about environment -> perceive, store and process info = senses
insight learning
The process of learning how to solve a problem or do something new by applying what is already known
observational learning
learning by observing from parents and other members of species -Mammals and vertebrates -Traditions passed down to generations
Play
Practicing behaviors and exercise
ex. Tag exercises behavior of hunting
social learning
Learning through observing others. -Forms roots of culture
altruistic behavior
self-sacrificing behavior that benefits another individual or individuals
social behavior
All interactions taking place between members of the same species -Rituals to warn, appease, court, defense
Dominance in Species- Alpha: Controls pack and resources and access to it Beta....Omega (Lowest)
Modes of Communication
Visual Verbal Auditory Chemicals- Pheromones (insects, mammals, reptiles)
agonistic behavior
Competition that determines who wins a prize, such as food, mates, or Alpha dominance.
ritual
a ceremonial act; a customary procedure; a symbolic activity
monogamy
marriage with one mate at a time -> No sexual Dimorphism
Polygyny
One male, several females. -Strong sexual dimorphism
Polyandry
One female, several males. -Strong sexual dimorphism
Tinbergen
study of red stickleback aggression (FAP)with red underbelly
Von Frisch
studied honeybee communication
Konrad Lorenz
researcher who focused on critical attachment periods in baby birds, a concept he called imprinting