Nutrient cycling is strongly regulated by vegetation. When plants are not present, nutrients are lost from the system.

pages 1213-1214

Fig. 54.21

Bioscience 2005

Ecologists are recognizing the need of understanding how landscapes (comprise different ecosystems) and food webs interact.

Gizzard shad

Ohio reservoir

Ecosystem. All the organisms living in a community AND the abiotic factors with which they interact.

Ecosystem Dynamics1- Energy flow Primary production gross and net

aquatic (light and nutrients). terrestrial (climate and nutrients). Secondary production

gross and net production and trophic efficienciesbiomass and number pyramids

green world hypothesis.

2- Matter (chemical) cycling Biogeochemical model. Water, carbon, nitrogen. Role of decomposers. Vegetation regulation.

1- Is the final cumulative? Can we have some sort of study guide?

SOME questions from February 24th

2- What happens to the rest of the light energy if only 1% is used?

3- How would omnivores be classified in consumer nomenclature?

6- If we need 2,000 calories per day and maybe half go out as feces, does that mean that we use only 10 calories for growth per day?

4- If organic and inorganic materials are only recycled, where are they from?

5- Is there any way to artificially produce photosynthesis to limit CO2?

The world's population continues to grow but at a slower pace. The world's population is expected to rise from the current 6.5 billion to 9.1 billion by 2050, the UN says.

World population 'to rise by 40%'

Introduction to Animal Evolution

What is an animal?• How would you know?

• What are the challenges that all animals must deal with?

• Are there some fundamental similarities in the ways that animals solve these problems (similar adaptations) ?

Major Themes -->

Growth & Development• form and function are related

Compare the means of support for animal and plant bodies.

• differentiation and specialization into tissues– tissues, organs, and organ systems– body plan, size, and symmetryHow is it possible that cells of the same animal can have a

different structure and function?

• reproduction– sexual and asexual– developmental stages

What is significant about the fact that larval forms are “sexually immature”?

Sensing and Responding to the Environment

• sensory systemsDescribe what is meant by “environment” in this context. Provide some examples of conditions that are monitored.

• motor systems (locomotion)What special tissue(s) enable this kind of movement?

• feeding and digestive functions Describe some examples of how body

structure is related to feeding style.

Internal Regulation• energy balance

What factors may influence an animal’s “energy budget”?

• transport– water– nutrients and wastes– gas exchangeHow do animals cope with abiotic stresses?

• intercellular communication– local– long distance

Provide one example of each type of intercellular communication.

Fig 28.8

Proposed evolution of the animals

Early embryonic development can help organize the diversity of animal life

What type of cell division occurs during cleavage?

When does the body form take on a “tube within a tube” appearance?

Patterns in Animal Evolution• Simple to more complex body form• Hypothesized colonial flagellated protist ancestor• Cell aggregates, to a gastrula-like (or tissue-grade)

“protoanimal” to

Fig. 32.3

Which stages demonstrate cell differentiation? … morphogenesis?

The Parazoa - Phylum Porifera

• No gastrulation occurs during development; no true tissuesIf sponges have no muscle or nerve tissues, how do they accomplish movement of water into the spongocoel?

Describe at least two functions of amoebocytes.

How would you describe the feeding strategy?

“pore-bearers”

Patterns in Animal Evolution (continued)

tissues organized into organs and organ systems (a “tube w/in a tube” body plan, with 3 embryonic germ layers)

Fig. 32.1Characteristics of the body plan (anatomy) and embryonic development are key to understanding the relationships between different animal groups.

Mesoderm (although, not in all animals)

Discuss the concept of “stem cells” in the context of animal embryology.

Patterns in Animal Evolution (continued)

• Bodies with no symmetry to bodies with symmetry– Branch Radiata

• 2 germ layers: ectoderm & endoderm

– Branch Bilateria• 3 germ layers

Which body form demonstrates cephalization?

Describe at least one example of an animal with a high degree of cephalization. What other characteristics are associated with cephalization?

Fig. 32.5

Patterns in Animal Evolution (continued)

Bodies with no body cavity (e.g. flatworms)

to bodies with a “false” body cavity

(e.g. rotifers and round worms)

to bodies with a “true” body cavity

Fig. 32.6

pseudocoelom

What normally fills the pseudocoelom?

coelom

What do the colored layers represent?

Coelomates

• Differences include:• Cleavage• Fate of blastopore• Process of coelom

formation

Name one organism representative of the animal groups listed at the top of the figure.

Fig. 32.7

How is structure related to function at major stages in the life cycle of a sea star?

What can early embryonic development tell us about phylogentic relationships in animals?

What is metamorphosis, and how is it different from morphogenesis?

Which animals have a body cavity?

What are the possible functions of a body cavity in animals?

Traditional Animal Phylogentic Tree

Animal Phylogeny – Modern

Fig 32.8

• Based on sequences in ribosomal RNA (molecular systematics)

• Acoelomate flatworms lost their coelom

• Coelom development happened early

• Combine phyla with lophophore and trocophore larvae

• Combine phyla that molt (ecdysis)

Tissues allow for different cells to take different roles: cnidocytes, unique in the animal kingdom, and extracellular digestion by gastrodermis allow food larger than individual cells.

X X X XXX

Plylum Cnidaria “cnidarians”

• extracellular digestion by gastrodermis allows food larger than individual cells

• Radial symmetry - detect and respond to stimuli from any direction

• Muscles and simple nerve net

Fig 33.6

Fig 33.4

Polyp vs. medusa

• 2 cell layers

– Skin

– Gastro-vascular cavity lining

• 2 body forms

– polyp

– medusa

Hydra eating

Swimming jelly fish

Phylum Platyhelminthes – “flat worms”• Bilateral symmetry with some cephalization; gastrovascular

cavity• A thin body between dorsal and ventral surfaces• NO coelom (acoelomate)• Flatworms, trematodes, tapeworms

Fig 33.12

Phylum Nemertea - “ribbon worms”

Photo from: http://www.seaslugforum.net/factsheet.cfm?base=nemertea

•Actually acoelomate, but some similarities to the protostomes

•Complete digestive tract; closed circulatory system

What are the advantages of a complete digestive tract?

…of a closed circulatory system?

Bivalves: Bivalves: clams, etc.clams, etc.

Phylum mollusca – “mollusks”

• Over 150,000 spp; mostly marine

• Soft body protected in most by a hard shell made of calcium carbonate

Gastropods: Gastropods: snails, slugssnails, slugs

Polyplacophora: Polyplacophora: chitonschitons

Cephalopods: Cephalopods: squid, etc.squid, etc.

Fig 33.20

Fig 33.17

Fig 33.18

Fig 33.22b

Mollusk anatomy

• Important consumers:– Filter feeders– Grazers– Carnivores

• 3 Main body parts:– Foot

• movement– Viscera mass

• internal organs– Mantle

• secretes shell; gas exchange

Most use a strap like rasping organ called a radula to scrape food; cephalopods have a beak