History of Life Flashcards Preview

Biology 1114 > History of Life > Flashcards

Flashcards in History of Life Deck (18):
1

Earth Formation

We are made of stars

2

Hadean

(ca 4600-3850 Ma) Differentiation of earth into crust, mantle, and core. Origin of atmosphere. formation of freshwater

3

What is life

autonomous replication (mitosis/meiosis), complexity, ability to evolve

4

Requirements of life

energy source, basic chemicals, fitting external environment

5

Archean

(3850-2500 Ma) Origin of life at 3800 Ma. Photosynthetic organisms 3500 Ma. Oxygen environment 3500-2800 Ma

6

Continents Form

3400, collisions of smaller land masses

7

Archaean life

Various Bacteria, Archaea

8

Proterozoic

(2500-542 Ma) origin of Eukaryotes, multicellular soft bodied animals

9

Eukaryotic Cell

DNA storage, RNA transcription, Membrane bound organelles

10

Serial Endosymbiosis Theory

Eukaryotic cells evolved when aerobic bacteria affected larger host cell. Ex Chloroplast/mitochondria

11

Challenges of Multicellularity

Need for support, difficult reproduction, surface to volume ration goes down as size increases, metabolic demands.

12

Cambrian Explosion

sudden appearance of diverse animal forms 450 mya

13

Intrinsic explanations (Cambrian explosion)

genes duplicated in bilaterians

14

Extrinsic Explanations (Cambrian explosion)

sufficient O2 became available for larger animals, or arms race with evolution

15

Abiogenesis

Life originated from abiotic precursors that existed here on earth - T. H. Huxley

16

Panspermia

Life on earth originated from biotic or abiotic precursors that arrived from extraterrestrial sources. Murchison meteorite carried amino acids

17

Miller Urey experiment

synthesized organic compounds from inorganic precursors, experiment created 20+ different amino acids

18

RNA world Hypothesis

early life based on RNA, Short lived once oxygen became abundant, DNA is more stable