1 / 25

Introduction To Animal Evolution

Introduction To Animal Evolution. Chapter 32. Animals 1 st appeared in Precambrian in waters, spread to land. 5 criteria that define animal: 1 Animals multicellular, must get food through ingesting other organisms or organic material.

ormand
Download Presentation

Introduction To Animal Evolution

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Introduction To Animal Evolution Chapter 32

  2. Animals 1st appeared in Precambrian in waters, spread to land. • 5 criteria that define animal: • 1Animals multicellular, must get food through ingesting other organisms or organic material.

  3. http://www.biology.wustl.edu/plant/simplealgalsystems1.jpg

  4. 2Animals do not have cell walls. • 3Animals have nervous tissue to conduct impulses and muscle tissue for movement. • 4Most animals reproduce sexually with diploid stage being dominant. • 5Animals have special regulatory genes (Hox genes) help zygote form into animal.

  5. Branching of evolutionary tree • 1st branch point splits Parazoa (lack true tissues) from Eumetazoa (true tissues). • Parazoa include sponges. • Eumetazoans divided into 2 major branches, partly based on body symmetry.

  6. http://www.sciencedaily.com/images/2007/07/070705153000.jpg

  7. Radial symmetry - phylum Cnidaria and phylum Ctenophora. • Bilateral symmetry (left and right side) - rest of phyla.

  8. Bilateral symmetry - cephalization, - concentration of sensory equipment towards head. • Difference between 2 groups - presence of germ layers - layers of embryonic tissue that form various tissues and organs.

  9. http://www.guam.net/pub/sshs/depart/science/mancuso/apbiolecture/27_Animalia/Annelida/Image11.gifhttp://www.guam.net/pub/sshs/depart/science/mancuso/apbiolecture/27_Animalia/Annelida/Image11.gif

  10. Bilaterally symmetric animals - 3 germ endoderm (innermost), mesoderm (middle) ectoderm (outermost). • Bilateral animals split according to presence of body cavity (fluid-filled space separating digestive tract from outer body wall) and what cavity looks like.

  11. http://universe-review.ca/I10-13-layers.jpg

  12. Acoelomates (phylum Platyhelminthes) have solid body, lack body cavity. • Some organisms - body cavity - not completely lined by mesoderm. • Pseudocoelomates include rotifers (phylum Rotifera), roundworms (phylum Nematoda).

  13. Coelomates organisms with true coelom, (fluid-filled body cavity completely lined by mesoderm). • Body cavity has many purposes including cushioning organs, allowing them more room to grow.

  14. Coelomate phyla divided based on differences in development. • Many protostomes (mollusks, annelids, arthropods) undergo spiral cleavage. • In many protosomes, blastopore develops into mouth; 2nd opening at opposite end of gastrula develops into anus.

  15. http://chsweb.lr.k12.nj.us/mstanley/outlines/animals/antax/image51.gifhttp://chsweb.lr.k12.nj.us/mstanley/outlines/animals/antax/image51.gif

  16. Zygotes of many deuterostomes undergo radial cleavage. • Deuterostomes - blastopore usually develops into anus, mouth derived from 2nd opening.

More Related