33 Deuterostome Animals

33 Deuterostome Animals 33.1 What is a Deuterostome? 33.2 What Are the Major Groups of Echinoderms and Hemichordates? 33.3 What New Features Evolved in the Chordates? 33.4 How Did Vertebrates Colonize the Land? 33.5 What Traits Characterize the Primates?

VERTEBRATES! There are some VERY cool pics and stories in Ch 33, but all you really need to focus on is the Mammal Section.

33.3 What New Features Evolved in the Chordates? Vertebrates: a jointed, dorsal vertebral column replaces the notochord during early development. Vertebrates have radiated in marine, freshwater, and terrestrial habitats.

Figure Chondrichthyans

Figure Diverse Ray-Finned Fishes (Part 1)

Figure Diverse Ray-Finned Fishes (Part 2)

Figure The Closest Relatives of Tetrapods (A)The Coelacalnth...was thought to be extinct!!!

Figure The Closest Relatives of Tetrapods (B) lungfish

Figure The Closest Relatives of Tetrapods (C)

Figure In and Out of the Water

Figure Diversity among the Amphibians

Figure An Egg for Dry Places

Figure Reptilian Diversity (A)

Figure Reptilian Diversity (B)

Figure Reptilian Diversity (C, D)

Figure Archosaurs (A)

Figure Archosaurs (B)

Figure Mesozoic Bird Fossils

Figure A Major Evolutionary Breakthrough

Figure Diversity among the Birds (Part 1)

Figure Diversity among the Birds (Part 2)

MAMMALS!!!

33.4 How Did Vertebrates Colonize the Land? Small mammals coexisted with dinosaurs for millions of years. Mammals increased in size and number after the extinction of dinosaurs.

33.4 How Did Vertebrates Colonize the Land? Characteristics of mammals: Sweat glands Mammary glands Hair Four-chambered heart—completely separates oxygenated from deoxygenated blood

33.4 How Did Vertebrates Colonize the Land? Just FYI, don’t need to know: Mammal eggs are fertilized internally; embryos undergo development in uterus Hair is greatly reduced in the cetaceans (whales and dolphins) and humans. Cetaceans have a layer of fat for insulation; humans learned to use clothing.

33.4 How Did Vertebrates Colonize the Land? Just FYI Living mammals (5,000 species) in two major groups: Prototherians: duck-billed platypus and echidnas—lack a placenta, lay eggs, and have sprawling legs. Therians—all other mammals.

Figure Prototherians

33.4 How Did Vertebrates Colonize the Land? FYI Therian clade has two subdivisions: Marsupials: carry and feed young in a ventral pouch. Young are born early, and crawl into pouch for further development. Most species are in Australia and South America. Eutherians—placental mammals. Young are more developed at birth.

Figure Marsupials

Table 33.1 Major Groups of Living Eutherian Mammals (Part 1)

Table 33.1 Major Groups of Living Eutherian Mammals (Part 2)

33.4 How Did Vertebrates Colonize the Land? FYI Eutherians are extremely varied. Extinction of non-avian dinosaurs allowed radiation into a large number of ecological niches. Some species assumed the role of dominant terrestrial predators.

Figure Diversity among the Eutherians (Part 1)

Figure Diversity among the Eutherians (Part 2)

33.4 How Did Vertebrates Colonize the Land? FYI Herbivores have influenced evolution of plant spines, tough leaves, toxic compounds, and difficult-to-eat growth. Herbivores in turn evolved adaptations to the teeth and digestive systems; an example of coevolution. Large size evolved in several herbivorous lineages.

33.4 How Did Vertebrates Colonize the Land? FYI Several eutherian lineages returned to aquatic habitats. Cetaceans evolved from artiodactyl ancestors. Limbs became modified as flippers.

33.5 What Traits Characterize the Primates? Eutherian primates radiated from a small, arboreal, insectivorous mammal. Grasping limbs and opposable digits were a major adaptation to arboreal life. Two main clades: prosimians and anthropoids.

Figure A Current Phylogenetic Tree of the Primates

33.5 What Traits Characterize the Primates? FYI Prosimians (lemurs, pottos, and lorises) are now restricted to Africa, Madagascar, and tropical Asia. Mainland prosimians are arboreal and nocturnal. On Madagascar, there was a radiation of lemurs. Some are terrestrial and diurnal.

Figure A Prosimian

33.5 What Traits Characterize the Primates? FYI Anthropoids (tarsiers, Old World monkeys, New World monkeys, apes, and humans). All New World monkeys are arboreal, many have prehensile tails. Some Old World monkeys are arboreal, others are terrestrial; none of them have prehensile tails.

Figure Monkeys

33.5 What Traits Characterize the Primates? FYI Lineage leading to modern apes split from Old World monkeys about 35 million years ago. Asian apes—gibbons and orangutans— descended from two of the ape lineages.

Figure Apes (Part 1)

Figure Apes (Part 2)

33.5 What Traits Characterize the Primates? Need To Know the Rest of the Chapter! Lineage split leading to chimpanzees and hominid clade occurred about 6 million years ago. Earliest protohominids (Ardipithecines) were bipedal. Forelimbs free, to manipulate and carry objects. Eyes elevated to look for prey. Bipedal locomotion more energetically economical.

33.5 What Traits Characterize the Primates? Australopithecines descended from Ardipithecines. most complete skeleton found to date is “Lucy” (Australopithecus afarensis), in Ethiopia; about 3.5my old.

33.5 What Traits Characterize the Primates? Two types of Australopithicines lived in eastern Africa about 4–5 million years ago: Paranthropus and A. afarensis. A. afarensis probably gave rise to genus Homo.

Figure A Current Phylogenetic Tree of Homo sapiens and Our Close Extinct Relatives

33.5 What Traits Characterize the Primates? Homo erectus used tools and fire for cooking. Survived in Eurasia until about 250mya. Fossils of a H. erectus descendent found (Indonesian island) These H. floresiensis fossils were only 18,000 years old.

33.5 What Traits Characterize the Primates? In lineage leading to Homo sapiens, brain size increased rapidly while jaw muscles decreased in size. Enlargement of brain relative to body size was probably favored by increasingly complex social life. Features that increased communication between individuals would have been favored.

33.5 What Traits Characterize the Primates? Several Homo species existed in the mid- Pleistocene; all hunted large mammals. Rituals and a concept of life after death emerged: CULTURAL EVOLUTION! Homo neanderthalensis was widespread in Europe and Asia. They may have been exterminated by H. sapiens known as Cro-Magnons.

33.5 What Traits Characterize the Primates? Cro-Magnons used sophisticated tools and created remarkable cave paintings. They spread across Asia and reached North America about 20,000 years ago, quickly spreading through the Americas.

33.5 What Traits Characterize the Primates? Our ancestors developed large brains, complex behaviors, and language. Complex cultures developed in which knowledge and traditions are passed from one generation to the next. Facilitated development of agriculture and pastoralism. This led to sedentary lives, cities, and occupational specialization.