Download Key Concepts: Adaptive Radiation & Cambrian Explosion in Life's History and more Quizzes Biology in PDF only on Docsity!
TERM 1
2 important points to study when considering
the history of life
DEFINITION 1
- periods when species originate and diversify rapidly2. periods when species go extinct rapidly TERM 2
adaptive radiation
DEFINITION 2 when a single lineage produces many descendant species that live in a wide diversity of habitats and use a wide array of resourcese.g. the Hawaiian silverwoods TERM 3
the 3 hallmarks of adaptive radiation
DEFINITION 3
- they are a monophyletic group2. they are speciated rapidly3. they are diversified ecologically (in terms of the resources they useand the habits they occupy) TERM 4
two general mechanisms that can trigger
adaptive radiations
DEFINITION 4
- new resources2. new ways to exploit resources TERM 5
niche
DEFINITION 5 the range of resources that a species can use and the range of conditions that it can tolerate
TERM 6
ecological opportunity
DEFINITION 6 meaning the availability of new or novel types of resourceshas driven a wide array of adaptive radiations TERM 7
the evolution of a key morphological traits
allowed descendants to:
DEFINITION 7
- live in new areas2. exploit new sources of food OR3. move in new ways*it triggered many of the important diversification events in the history of lifee.g. the evolution of wings, reproductive structure of angiosperms, chichlids (fish that evolved a unique set of jaws in their throats), feathers and wings give some dinosaurs the ability to fly TERM 8
Cambrian Explosion
DEFINITION 8 the evolution of creatures with shells, exoskeletons, internal skeletons, legs, heads, tails, eyes, antennae, jaw-like mandibles, segmented bodies, muscles, and brains during the Cambrian perioddocumented by 3 major fossil assemblages (1) 570 mya, (2) at 565 to 542 mya, and (3) at 525 to 515 mya TERM 9
fauna
DEFINITION 9 a collection of animal species TERM 10
theories as to what triggered the Cambrian
explosion
DEFINITION 10
- higher oxygen levels2. the evolution of predation3. new niches beget more new niches4. new genes, new bodies**** most/all of these hypotheses could be correct. they are not mutually exclusive****
