1. Evolution toward Technology ASTR 1420 Lecture 5 Sections 6.5, 12.2

2. Evolution of Human • Traits of tree life transformed to good human skills • Grabbing branches  dexterous hands • Swinging among branches  depth perception  good hand-eye coordination • Good parental cares for youngsters • Primates : having hands, hand-like feet, forward-facing eyes • Common myth: Apes Human

3. Humanoid • Numerous hominid species • no “missing link” in human evolution Toumai

4. During the past 40,000 years, we did not make any significant evolutionary changes… Cultural & Technological Evolution • Dramatic changes • cultural evolution : via transmission of accumulated knowledge • Cultural evolution • is far more important than natural evolution.. • accelerates over time • Beginning a new trend? Technological evolution : increased technology  new discoveries  more advanced technologies  … • Active Evolution: • genetic engineering • modern medicine • not limited by Darwinian evolution anymore…

5. Is intelligence inevitable? “No” • biology might be common… • we (human) are the only one with Technology in the Universe (or at best, extremely rare) • over 3.5 Gyr of life, only 200 years of technology • our existence is due to some chance events • evolutionary stress from Snowball Earth or mass extinction impacts… • no mammal domination if there was no asteroid impact 65 Myr ago. “Yes” • evolutionary pressure for intelligence (lions and gazelles) • even if there was no human, other technological species might have emerged instead. • Convergent evolution  intelligence

6. acquisition of the same biological trait in unrelated lineages  natural selection often produces analogous adaptations. Convergent Evolution • Dolphins and Sharks streamlined “torpedo-shape” body form • greater speed for better survival to catch preys • Eye-sights • most multi-cellular animals can “see” • eyes evolved independently 8+ times! • Flights • bats, birds, pterodactyls, some insects… • Sonar (echolocation) • whales/dolphins, bats

7. Bioluminescence • It has evolved independently at least 40 times! E. A. Widder (Science, 2010, 328, 704) Bioluminescence has resulted from some intriguing evolutionary adaptations. • In the deep- sea anglerfish Linophrynecoronata, bioluminescence from the esca is bacterial in origin, whereas that from the chin barbel is an unidentified intrinsic chemistry. • In the octopus Stauroteuthissyrtensis, its suckers are photophores. • In the tunicate Pyro-soma atlanticum, luminescence originates from putative bacterial endosymbionts.

8. Extra credit… All crabs look quite similar… but DNA information tells us that they are from many different ancestors (from shrimps, lobsters, etc.). Crablike body and walking must be an outcome of the convergent evolution. What’s the benefits of these traits?

9. Encephalization Quotient (EQ) = the ratio of the actual brain mass to the expected brain mass of a typical animal that size Human : 7 Chimpanzee : 3 Dolphins : 2.5-4.5 Hippo : 0.27 Raptors : 5.5 Troodons : 5.8 Measuring Intelligence

10. A trend toward increasing intelligence? Factors encouraging intelligence high, effective metabolism (2% body weight uses ¼ of energy) long period of parental care (to pass down knowledge) Natural selection on intelligence gazelle + lion : mutual pressure intelligence comes with a cost high metabolism and handling heavy head. Evolution of Intelligence If only for survival, for given limited resources, other capabilities can be equally good faster running, better fighting, etc.

11. Pass down accumulated knowledge to next generation!

12. Technology: inevitable? • A pathway from higher brainpower to science and technology seems apparent… • For technology, there are some other needed traits (e.g., dexterous hands) • dolphins : with intelligence and social structure. • need to manipulate complex tools!! • Even for advanced civilizations, do they head toward interstellar radio communications or space travels? What about the Woodpecker’s niche? Need to find an evidence of alien technology on other habitable worlds!

13. If human disappears on the Earth now, will there be a different species to carry out the evolution toward technology? Watch “Smart Monkeys” from PBS NOVA!! (or search for “Clever Monkeys” in Youtube)

14. In summary… Important Concepts Important Terms Convergent evolution Encephalization Quotient • Cultural evolution • Technological evolution • Woodpecker’s niche • Chapter/sections covered in this lecture :6.5 & 12.2