AST251H1 Lecture Notes - Lecture 6: Stromatolite, Ciliate, Covalent Bond

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST251H1
• Professor: Hilding Neilson

Document Summary

Dar(cid:449)i(cid:374) sa(cid:449) that e(cid:448)olutio(cid:374) is(cid:374)"t pushed for(cid:449)ard (cid:271)(cid:455) spo(cid:374)ta(cid:374)eous effe(cid:272)ts, (cid:271)ut (cid:271)(cid:455) (cid:449)hat (cid:449)orks the (cid:271)est. Natural selection can also be artificial selection cuased by humans. The problem with groupings is that its solely based on superficial sppperance. Tree of life: the bacteri and archae are single celled organisms, the eucarya can be either single celled or multi cellular. Eukarya are more closely related to the archae than to bacteria. Car(cid:271)o(cid:374) a(cid:374)d o(cid:454)(cid:455)ge(cid:374) are(cid:374)"t that (cid:272)o(cid:373)(cid:373)o(cid:374), (cid:374)itroge(cid:374) is (cid:448)er(cid:455) (cid:272)o(cid:373)(cid:373)o(cid:374). Cno peak is at 1 part in 1000. For every 1000 h atoms, theres 1 c,n,o. A covalent bond is where 2 atoms share electrons. If si life was possible, because its so common we would expect to see si life by now. Thus we tend to rule it out and only have carbon based life. Water is a simple molecule but it has lots of complex properties.