Chapter 32 Mammals

Question of the day What is the largest mammal living in the world? Blue Whale What was the largest mammal ever on earth Sea & Land? Baleen Whale (110’ long) Ancestor to rhinoceros (23’ tall)

Ch. 32 Essential Questions What special adaptations did mammals evolve? What kinds of mammals are there? What are the main evolution steps to modern humans?

32-1 Mammal Characteristics What sets mammals apart from other species? Mammary Glands, or the ability to produce nourishment for young Other Distinctive features Breathe air Hair 4 Chambered Heart Endothermic Maintain Homeostasis Nourish Young

Early Mammals When did the 1st mammals arrive? 250 - 290 million yrs ago in Permian period Descendants of reptiles 1st true mammals - 220 million years ago Also Triassic period Dinosaurs started & ended Cretaceous period Cenozoic means rise of mammals Humans came along 10 mill yrs

Form & Function of Mammals What do all mammals do? Regulate internal temp: Homeostasis Subcutaneous fat Endothermic

Feeding Mammals have high metabolism: Must eat 10 times food as reptiles Can eat many things (Herbivores, omnivores & carnivores) Evolved best ways to eat over time: Hunters Plant eaters Strainers

Other Processes Respiration Breathing in O2 + out CO2 Circulation Move blood, nutrients around Excretion Getting rid of wastes Response Involuntary reactions to stimuli Movement Adaptations to get around Reproduction Internal Fertilization

31-2 Diversity of Mammals Three different types of mammals Separated by birth methods Monotremes - Egg Layers Marsupials - Live Birth, grow in external pouch Placental Mammals

Other Cool Ones Sirenians Chiropterans Lagomorphs Xenathrans Proboscideans

Primates & Human Origin What is a primate? How is it different? Binocular Vision Rotating Joints in arms & legs Fingers (opposable thumb) & toes Well-developed cerebrum

Primate Evolution 3 Main Types of Primates - what are they called? Anthropoids Monkeys Apes Humans Whats the difference? Humans walk upright, monkeys & apes on all fours

Apes vs. Monkeys What are some examples of Monkeys & Apes? Apes (Hominids) Orangutang, Gorilla, Baboon Monkeys (Prosimians) Spider, Lemur How do they differ? Size - Big vs. Small Habitat - Ground vs. Tree Limbs - 2 feet, 2 hands vs. 5 arms (tail) What is monkey’s tail called? Prehensile

Time Frame for Evolution Hominids - 6 million yrs old Gave rise to Homo Habilis 2.5 million yrs ago Meaning Handy Man (tools) Used tools, walked more on 2 feet

The next step 2 million years ago Homo Ergaster or “workman” Closely related to Homo Erectus or upright man These species migrated from Africa to Asia & N.America

Finally Modern Day Final Predecessors to Humans: 500,000 yrs ago Neanderthals - Europe & Asia Used Stone Tools & lived in social groups, 1st sounds 150,000 yrs ago Cro-Magnons - Europe More sophisticated tools (weapons), appearance of words 40,000 yrs ago modern Homo Sapiens

Summary Main Ideas: Man Evolved as a species from apes Each time - Got Bigger, Less Hairy, Smarter, More Social, Explored further around the globe